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T-D2-IN&OS_Service M..

1. Ver 1 00 6 Wiring diagram The diagram below refers to both the T D2 IN and T D2 OS BL Hue A2 a 120 VAC G Geen w our ge BK box Y Yel ow Qo i Ground Orange A3 1 BR Brown PCB Trans BR BR forner BR BR O O G G Ground wAL 2 CA amp o 77 Ww Heater E H1 AA Heater 1 cd a a pr ot ect i on O ther nast at B mE
2. 3 QUTH failure gt 311 bl i nk YES failure 331 blink BV nodul at es 3PCB failure gt 701 bl i nk L 5SV circuit fail ure 9 510 bl i nk FI ow sensor CFF C Faucet cl oses Fan not start 611 bl i nkl oper ati on GN Fan notor stop operation N 20sec later Fan notor stop operati on FAV Fl ow Adj ust Val ve BV Bypass Val ve lt Getect s eo Fal se fl gt gt 721 bl i nk EA Panor Or EE OHCF Over Heat Cut off Fuse DO 154A MV Main gas Valve YES SVI Sol enoi d Val ve 1 See the section 6 Igniter CN 5 2 Sol enoi d Val ve 2 See the section 6 SV3 Sol enoi d Val ve 3 See the section 6 CPV Gs Proportional Val ve I nTH Inlet thermistor Output ther m stor qaa 1111 blink M TH M xi ng ther ri stor Rei gni ti on Print Circuit board Success Conqput board 121 blink Ar Fuel Ratio rod SV2 ON A Igni ter OFF GPV ON M CFF Fl ame rod NO SV2 CFF CPV CFF 5sec later SV1 SV3 CFE I YES T Bur ni ng ON Igniter CFF lt Proporti onal co
3. X E 0 Mxing M Ther m st or AY U ja A 2 gt G V A Drain pl ug H C 5 Gas proportional val ve T L Gas solenoid valve 2 D Gas solenoid valve 3 ni Inlet drain Ther m st or plug filter ransf or ner When a hot water tap is opened cold water enters the T D2 IN or T D2 OS The water flow sensor detects this water flow and sends this information to computer The computer initiates fan motor and sends signal to igniter to create ignition spark The main proportional and solenoid gas valves open to allow gas input The gas ignites and flames appear inside the burner chamber Water circulates through the heat exchanger and is heated up to the set temperature DX oS JP 23 d Using thermistors to measure temperatures the computer modulates the gas and water valves to ensure proper output water temperatures 8 When the tap is closed the T D2 IN or T D2 OS shuts down CONFIDENTIAL T D2 IN T D2 OS Service M anual
4. Q Increase button om L Decrease button Red light lt 91 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 4 AFR rod function Function The AFR rod checks flame conditions during combustion When the AFR rod detects unexpected flame conditions the computer board of the T D2 adjusts the fan motor speed to ensure that air and fuel are always at a proper mixture ratio minimizing emissions AFR normal range of values Unit A Gastype LPG Natural gas LPG Natural gas Combustion 8 8 to 32 5 12 5 to 35 0 2 5 to 50 0 9 0 to 38 0 mode 1 5 to 13 2 2 0to 11 5 3 5 to 18 5 2 0 to 10 5 If the detected AFR value is higher than the normal value the FM speed is increased If the AFR value is lower than the normal value the FM speed is decreased These values are read with the front cover close Measure the values after burning the water heater for ten minutes The AFR stage can be confirmed in Diagnostic Mode Section 12 1 lt The relationship between the AFR stage and the 10 and 99 error codes gt FM Stage 15 13 5 Condition of AFR stage 0 to 5 Air rich In order to solve the air excess problem the fan motor 991 error cod
5. 165 05nm The computer board 6 1 2 differs from one in the T K3 SP OS ij Tolo To b T dh T dh d fi L A ju 5 3 8 138rm 31 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 16 Transformer Unit Part 02 Takagi Part EKHO9 Checkpoint 1 2 transform input voltage from 120 to 100 VAC Every electrical component of the water heater is designed to only work with a 100 VAC power supply therefore the water heater comes equipped with this transformer 1 There is no power coming from the transformer Failure events 2 The voltage from the power supply cannot be converted to 100 VAC 1 The water heater does not operate due to lack of power from Effects on the water tran
6. levels with the appropriate level being set up by the installer until the abnormal sound problem is solved The desired level can be specified at the left bank of dipswitches No 4 and No 5 on the computer board See the table in the next page ud Left bank of dipswitches 0 to 2 000 ft Standard setting Left bank of dipswitches No 4 OFF FM function the fan motor speed increased by 6 aft bank of dipswitches No 4 ON 1 2 000 to 4 000ft T D2 IN the fan motor speed increased by 4 T D2 OS FM function the fan motor speed increased by eft bank of dipswitches No 4 OFF 2 4 000 to 6 000ft 12 T D2 IN S N the fan motor speed increased by 8 T D2 OS FM function khe fan motor speed increased by oft bank of dipswitches No 4 ON 3 Over 6 000ft 18 T D2 IN No 5 ON ithe fan motor speed increased by 12 T D2 OS Consult our Technical Services Department 4 If the abnormal sound problem persists even with a Level 3 setting please contact our Technical Service Department for advice Note that there are many high risks associated with manually changing the manifold pressures T D2 IN OS installation manual doesn t mention this function for safety purposes 61 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 11 Relay selection for the pump co
7. 26 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 11 Thermistors 407 Inlet EKK38 Inlet E1 Mixing Unit Part 408 Mixing Takagi Part EKKIA Mixing Checkpoint E2 Output at 0 411 Output EKK2T Output E3 Inlet M easures cold hot water temperatures in the water heater Unable to properly measure water temperatures within the water heater Effects on the water If the thermistors fail open or short error code appears before starting operation heater if thermistor If resistance values are just off The water heater will have temperature fluctuations fails in hot water 311 Output 321 Inlet 331 Mixing thermistors fails 1 Visual inspection connection breakage of wires and or debris on thermistor Diagnostic 2 Check voltages and resistance proper range of values shown below Inlet Black 42 Black 68 F 20 C 9 0 to 13 ka Color Number Output Black 12 Black 122 F 50 C 3 3 to 4 4 ka wires 176 F 80 C 1 4 to 1 8 Mixing Black 113 Black see table below for more resistance values ss Inlet thermistor 42 Blue TG gt IM ixing thermistor 113 Black Insulating i Output thermistor 12 Resistance values of thermistors as a function of temperature 25 00 20 00 Resisitance kQ O O1 O O O O 20 40 60 80 100 120 140 160 180 200 220 Temperature F 2 CONFIDENTIAL
8. 3 3 8 84 4mm The flow adjustment valve differs from one in the T K3 SP OS adj ust nent 1 7 8 47mm val ve Fl ow 24 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 9 Flow sensor Unit Part Takagi Part EK438 Checkpoint 2 Function Detects and measures water flow rate using a spinning impeller and magnetic pick up Failure events Unable to detect or measure any water flow rate Effects on the water heater Ignition sequence does not start water heater will not initiate any 441 only within Easy Link systems sensor fails 1 Visual inspection connection breakage of wires and or debris Diagnostic impeller 2 Check voltages proper range of values shown below Red Black 4 0 to 5 5 VDC Input Color Number of wires 1 0 to 4 0 VDC pulse White 85 Black 1 080 pulse min more than 18 Hz The flow sensor is assembled with the flow adjustment valve Fl ow adj ust nent dd 84 4nm The flow senor Fl ovv sensor 3 3 8 differs from one
9. TE OFF position 0 6 O ON position 12 18 OFF position ON position 4 No 6 ON position 8 N A N A N A Default 93 The function of the lower bank of dipswitches No Functions ON position OFF position 1 Parent Child setting for Easy Link systems Parent Child Default 4 5 6 Modeltvpe Output temperature settings See table to the right Default 122 F CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Default Disable EI Default Disable me CN 123456 400 CN 123456 ial 113F 45 C ON 123456 LL 122 50 DEFAULT 123456 njajn 123456 alla 158 70 C 123456 alal 176 80 C 94 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 6 Assigning unit numbers in the Easy link system A How to display the unit number Press the Increase button on the computer board The 7 seg LED will then display the assigned number for that T D2 IN or T D2 OS unit for 10 sec NOTE In a single unit installation the numbering system is disabled B How to reset and reconfigure th
10. Description Common parts for other models 461 192 Fastener 16 T K3 T K3 Pro T K3 SP OS T K r2 IN OS T K4 IN OS 462 EKK39 Fastener 16 25A T K3 T K3 Pro ii T K3 T K3 Pro T K3 SP T H2 DV T KJr2 IN OS 463 EKN50 Silicon ring T K4 IN OS T M 32 701 EK439 Computer board 702 EKHO9 T K3 T K3 Pro T K3 SP OS T KJr2 IN OS T K4 IN OS 703 EK428 T KJr2 IN OS T K4 IN OS 704 EKK3C 120VACwire T K3 SP OS T H2 DV OS T K4 IN OS 706 EKK4v 120VACPower ON OFF switch T K3 SP OS T H2 DV OS T KJr2 IN OS T K4 IN OS 707 EK441 Switch wire T K4 IN OS 708 EKK10 T K3 T K3 Pro 709 EKK11 T K3 T K3 Pro Gas valve wire Flame rod wire EKKOZ EH IG wire T K3 T K3 Pro 710 EH IG wire with freeze protection EKK40 T K3 OS 2 05 4 05 thermostat T K3 T K3 Pro T K3 SP OS T H2 DV OS 711 EKN 74 Igniter T KJr2 IN OS T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 712 EKK2M High voltage igniter cable T KJr2 IN OS T K4 IN OS T M 50 713 EKJ59 Freeze protection thermostat T K3 T K3 Pro T K3 SP 2 T K4 IN T M 32 714 EKK12 Proportional gas valve wire T K3 T K3 Pro T H2 DV OS 715 EKK36 Pump and multi cable T K3 T K3 Pro 117 EKK35 RS VG wire T K3 T K3 Pro 719 EKKIM Computer board cover T K3 T K3 Pro T M50 77 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 15 Revisions Version Description of changes Date 1 00 First edition 11
11. 0 1 0 to 9999 x10 hour Integrating flow of Unit 0 to 9999 x1 000 gallon Error code history displays most recent error code Error code history displays 2 most recent error code Error code history displays 3 most recent error code Clears memory in error code history N A Air Fuel ratio stage 0 to 16 normal condition 6 RE30 Simultaneously press the INFORMATION button and the BUZZER buttons on the TM RE30 while in mode 14 for at least 5 seconds to completely clear the memory in the error code history Mode 5 after 9 will be displayed as a number e g 10 11 16 on the TM RE30 After 16 the TM RE30 will cycle back to 1 again 49 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 2 Verifying functionality of computer board and Displaying error code history and Clearing error code history memory DRM The T D2 IN and T D2 OS has an Error call button on the computer board that provides the functions listed below 1 xi The button is located next to the 7 seg LED as shown in 3 S the picture to the right AL p Error call button js 7 seg LED Check if the computer board works properly 1 Turn on the ON OFF button of TM RE30 remo
12. 271nm 10 5 8 271mm 23 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 8 Flow adjustment valve Unit Part Takagi Part EK438 Checkpoint Controls water flow to properly control the output hot water temperature 1 Water leakage from valve Failure events 2 The valve cannot modulate or make open close positions 1 Water leakage from failed valve can damage other water heater components 2 Temperature fluctuations in the hot water output 3 Within an Easy Link system the 651 error code can occur Error codes when flow M 651 only within Easy Link systems adjustment valve fails only within Easy Link sy 1 Visual inspection connection breakage of wires motor drive locked due Diagnostic to scale buildup and or water leakage 2 Check voltages and resistance proper range of values shown below Color Number of wires Black Red 7 to 16 VDC and 0 09 to 0 2 ka The flow adjustment valve is assembled with the flow sensor e Effects on the water heater if flow adjustment valve fails Fl ow adj ust nent n Fl ow adj ust nent val ve Fl ow sensor 2 5 8 67 5mm gt E 5 BI ack C Red Flow adjustment valve
13. T D2 IN T D2 OS Service M anual Ver 1 00 10 12 Hi limit switch Unit Part Takagi Part EKN34 Checkpoint Based on bi metal thermal expansion Detects excessively high water temperature more than 194 F or 90 C in pipes of the heat exchanger After detection communication between the computer board and gas valves are severed shutting down the water heater instantly The 111 or 121 error codes will display 1 Unable to detect excessively high water temperatures if switch fails closed Failure events 2 Continuous detection of excessively high water temperatures regardless of what the actual water temperature Is if switch fails open 1 Unable to shut down the water heater if the water temperature from the heat exchanger exceeds 194 F 90 C Effects on the water Note The mixing and output thermistors always act as backup hi limit heater if hi limit switch detectors to detect excessively high water temperatures in the heat fails exchanger 2 The water heater is always shut down immediately after the ignition process and either the 111 or 121 error code will display 111 121 Function Error codes when hi limit The T D2 IN T D2 OS don t have the 141 error code that was used in our switch fails previous models This error code is now replaced by the 111 and the 121 error codes 1 Visual inspection connection breakage of wires Possibility also includes Diagnostic scale deposits inside the hea
14. 2 Listen for clunk sounds from the gas valves opening right after fan motor Diagnostic initiates 3 Check voltages and resistance of coils proper range of values shown below Blue Light blue MV 78 to 100 VDC during operation 0 9 to 1 3 Blue Green 5 1 78 to 100 VDC 1 3 to 1 9 Blue Orange 5 78 to 100 VDC during operation 1 3 to 1 9 ko Blue Red SV3 78 to 100 VDC during operation 0 9 to 1 7 White Red Proportional valve Effects on the water heater If valves fails during operation Color Number of wires 1 0 to 15 VDC during operation 20 to 40 O EKHOT for LP model and EKK5K for NA model is an assembly of the gas manifold with gas valve assembly For safety reasons these assemblies should be installed in the unit as a whole set The diagram below shows the gas valve assembly _4 1 4 108mm 7 8 22 2nm _2 5 8 67mm 1 Hi A t Mai n gas val ve f Proportional Valve Sol enoi d val ve 4 5 8 119mm 3 5 8 91 5109 1 3 8 34mm Proporti onal val 20 CO
15. T K4 IN OS T M 50 T M 32 121 EK436 Surge box plate T K3 T K3 Pro T K3 SP OS T KJr2 IN OS 150 EZP18 O ring P18 NBR Black T K4 IN OS T M 50 T K3 T K3 Pro T K3 SP OS T H2 DV OS 151 EK042 O ring P20 NBR Black T KJr2 IN OS T K4 IN OS T M 50 152 EKK3G Silicon ring T K3 OS T K4 OS T M 50 Rain protection plate in Exhaust 3 EKK53 T K3 SP OS r2 OS T K4 OS chamber 1 154 EKK56 Exhaust port T K3 OS r2 IN OS 201 TU002 Heat exchanger assembly IN 402 Exa38 Flow adjustment valve Flowsensor StS 403 EKKOU Bypass valve T K3 T K3 Pro T K3 T K3 Pro T K3 SP OS T KJr2 IN OS 404 EKK1U Water inlet T K4 IN OS T K3 T K3 Pro T K3 SP OS T KJr2 IN OS 405 EKK2B Inlet drain plug T K4 IN OS T K3 T K3 Pro T K3 SP OS T KJr2 IN OS 406 EKK2C Inlet water filter T K4 IN OS 407 EKK38 Inlet thermistor T K3 T K3 Pro T H2 DV OS T M 50 T M 32 408 EKKIA M ixing thermistor T K3 T K3 Pro T M50 T K3 T K3 Pro T K3 SP OS T K r2 IN OS 409 EKK1V Water outlet T K4 IN OS 75 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Item Part Description Common parts for other models T K3 T K3 Pro T K3 SP OS T KJr2 IN OS Outlet drain plug T K4 IN OS 50 411 EKK2T Output thermistor T K3 T K3 Pro T H2 DV OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS T M 50 412 EKN34 Hi Limit switch T M 32 T K3 T K3 Pro T K3 SP OS T K r2 IN
16. T M 50 T M 32 T K3 T K3 Pro T K3 SP OS 23 Flame rod 10 EKKOE T H2 DV OS T M 50 T M 32 0 0 T K3 T K3 Pro T K3 SP OS 24 Igniter rod 1 EKKOF T H2 DV OS T M 50 T M 32 Inlet drain plug water T K3 T K3 Pro T K3 SP OS 4 EKK2B filter T KJr2 IN OS T K4 IN OS 120 VAC Power ON OFF ER T K3 SP OS T KJr2 IN OS switch T K4 IN OS T H2 DV OS LP model T H2 DV OS 27 Gas valve assembly Included in 102 EKK5K NA model 28 Manifold por va 29 Gas inlet port N A N A 0002 T D2 IN T H2 DV OS 30 Exhaust chamber Included in 401 EK437 T D2 OS 31 Output thermistor 411 EKK2T PO 32 Bypass valve 403 EKKOU 9 NO CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 5 Schematic diagram The diagram below refers to both the T D2 IN and T D2 OS Hi limt SW O H C F ratio rod Out put Therm stor Fl ane rod Bypass val ve Igniter rod Fan motor I gniter Fl ow adj ustment val ve wth Fl ow sensor Heater Gas sol enoi d val ve 1 T je gas val ve
17. 9 lt 2 a m m H E N N EA E ESE SI Y t P 2 1 26mm COLD 2 7 8 71nm 1 7 8 47nm g COSO COLD 3 1 4 84mm 120V_1 3 8 36mm GAS 5 1 4 135nm u Hor 6 1 2 dean HOT 5 1 4 133mm L GAS 4 7 8 124nm 9 1 2 241mm Top view Bottom view HOT 5 1 4 133nm__GAS 4 7 8 124nm 13 1 3 334nm 5 1 8 130nm E E 3 Y ku Te A A n m A 0 V S ri 00 N m i 00 H N U m 9 lt Mm 4 gt C e go 9 A J y y A A y y COLD 3 1 4 84nm_ 120VAC 1 3 8 36nm CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 T D2 OS Side view Front view 13 3 4 350mm 10 254nm l 4 3 8 113nm 7 7 8 203mm 1 3 4 45nm 1 3 4 45nm 5 128mm l zija 5 8 4 G i gt fc E E m y N c B ES 4 bl Y 00 gt E j 1C al N N i Es _ p ae E 1 26mm COLD 2 7 8 71nm 1 7 8 47mm LAUNA A 4 COLD 3 1 4 84nm L 120V_1 3 8 36mm 22 HOT 5 1 4 133 GAS 4 7 8 124 HOT 6 1 2 164mm 1 4 133mm n
18. D2 OS s previous firing operation the computer Will continually check the temperatures of the inlet and output thermistors the output thermistor is the one that checks the temperature of the water immediately leaving the heat exchanger not the water leaving the T D2 IN or T D2 OS which is mixed with water from the bypass valve The automatic firing system will not activate at all unless these 5 minutes have elapsed When the computer checks for these temperatures the freeze protection firing system will activate if Tin lt 37 F and Tout 50 F OR Tour lt 37 F where Tin is the temperature of inlet thermistor and To is the temperature of the output thermistor 66 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 To sum it up in a chart Case 5 minutes have elapsed Inlet thermistor Output thermistor Will automatic iui ord temperature temperature firing be activated 1190 o Yo moves amy Mees NO n n Any a T D2 OS installation After 25 minutes have elapsed since the T D2 IN or T D2 OS s previous firing operation the computer will continually check the temperatures of the inlet and output thermistors The automatic firing system will not activate at all unless these 25 minutes have elapsed When the computer checks for these temperatures the freeze protection firing system will activate if Tin lt 37 F and Tout 50 F OR Tout lt 37 F where Tj is the temperature of in
19. Function Effects on the water 1 The freeze protection heaters will always be ON causing heat damage to heater if the freeze components inside the water heater protection thermostat 2 The freeze protection heaters will never be able to turn on even under fails freezing temperatures causing freeze damage to the water heater Error codes when the freeze protection N A thermostat fails 1 Visual inspection connection breakage of wires and or the body has been Diagnostic broken 2 Check resistance and voltage proper range of values shown below Black Black ON mode 90 to 110 VAC and less than 1 0 Color Number of wires itself OFF mode less than 1 VAC and more than 1 MQ Activation and deactivation temperature of the water heater s freeze protection system ON mode 36 5 F 46 3 F 2 7 F 2 5 3 5 1 0 C OFF mode above 46 4 F above 8 C 7 8 22 25 1 4 5 7mm 34 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 19 Surge box Unit Part 03 Takagi Part EK428 Checkpoint A2 A3 Protects the unit from high voltage and or high electric current caused by lightning Function There are 2 types of surge absorbers in the water heater Surge absorber A is activated by voltage higher than 220V the other one is activated by voltage higher than 680V 2 Short failure of the absorber 1 Unable to protect the computer
20. GPM Available set temperatures 99 to 185 F default 122 F Temperature dipswitch settings 104 F 113 F 122 F 131 F 140 158 F 176 F 185 F Bypass valve Yes Thermistors Remote controller model 3 thermistors In Out Mixing TM RE30 PCB model T D2 Indicators Red LED on PCB during operation amp 7 SEG LED Power supply control Freeze protection Surge absorber amp Power ON OFF switch Ceramic heaters and Auto firing system Self combustion improvement Air Fuel Ratio Detection System Easy Link system Yes Up to 4 units M ultiple system N A The manifold pressure measurement is based on conditions without front cover 3 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 2 Exterior view T D2 IN ide view side vie Front view 13 3 4 350nm 10 254mm l 3 9 8 101nm A 3 8 CIY mm 1 3 4 45nm 1 3 4 45nm e e N E i 1 3 8 36nm N
21. P P Igniter rod y Ciela G BL NL O e lt Ground Fiane rod 910 C BL BL _ 33 QHCF is 9 730 PL Adj ust R HR E BS 4 7 nent BK BK G Val ve O R O L pass R R 1 O ve BK BK ENS D G x 2 O Mul ti syste comect or s gt line LED 2 Parent MAX button tenes Q BK M xi ng butt on e BR t hernnstor BK Increase button d _ BK Decrease button O bbodo 2 F Qut put t rmstor Red LED AA b Error call button TM RE30 ni et 7 Seg LED control ES BK 11 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 7 Wiring diagram check points for diagnosis The table below applies to both the T D2 IN and T D2 OS Check iss Part and Description Color of wires Normal range poin White Black A A A1 100V Power supply 90 to 110 VAC Brown Brown A1 120V Power supply Black White 108 to 132 VAC B Igniter Purple Purple 90 to 110 VAC Bl Heater Black Black 90 to 110 VAC 78 to 100 VDC during operation 0 9 to 1 3 78to 100 VDC during operation 1 3 to 1 9 ko 78to 100 VDC during operation 1 3 to 1 9 ko 78to 100 VDC during operation 0 9 to 1 7 ko Less than 1 VDC Hi limit switch Blue Blue and less than 1 00 Less than 1 VDC Overheat cutoff fuse Blue Blue and less than 1 00 15 VDC D1 D2 Easy link connectors Black
22. Pro T K3 SP OS 6 Water inlet 404 EKK1U T KJr2 IN OS T K4 IN OS T K3 T K3 Pro T K3 SP OS 7 Water outlet 40 EKK1V T KJr2 IN OS T K4 IN OS T K3 T K3 Pro T H2 DV OS 8 Inlet thermistor 407 EKK38 T M50 T M 32 0 T 41 0 1 1 9 Mixing thermistor 408 EKKIA T K3 Pro T M50 T K3 T K3 Pro T K3 SP OS Overheat cut off fuse 3 EK333 T KJr2 IN OS T K4 IN OS T M50 11 Burner assembly 101 EKH5W T H2 DV OS Burners IM T K3 T K3 Pro T K3 SP OS 12 Hi limit switch 412 EKN34 T H2 DV OS T M50 32 T K3 T K3 Pro T K3 SP EKK25 T D2 IN EKK54 T D2 OS T H2 DV 05 T M 50 32 EKJ59 T D2 IN T K3 OS T K4 OS T K3 T K3 Pro T K3 SP T M 32 Freeze protection 713 thermostat EKK40 T D2 OS T K3 OS T KJr2 OS 4 05 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 Items in Common parts Description components for other models diagram 15 Flow sensor 402 EK438 TU002 T D2 IN 16 Heat exchanger assembly 401 EK437 T D2 0S T K3 T K3 Pro T K3 SP OS 17 Gas inlet 118 EKKIE T KJr2 IN OS T K4 IN OS T H2 DV OS T K3 T K3 Pro T K3 SP OS 18 Heater 414 EKK2R T KJr2 IN OS T K4 IN OS 19 Flow adjustment valve 402 EK438 pO 20 Surge box 703 EK428 T KJr2 IN OS T K4 IN OS 10 8 8 9 5 06 T K3 T K3 Pro T K3 SP OS Outlet drain plug 4 EKK2E T KJr2 IN OS T K4 IN OS T M 50 Air fuel ratio rod T K3 T K3 Pro T K3 SP OS 22 10 EKKOE AFR rod T H2 DV OS
23. Valve 6 Have a bucket or pan to catch the water from the drain SIN plugs of the T D2 IN or T D2 OS Unscrew the drain plugs to drain all the water out of the T D2 IN or T D2 OS Drain Plug Water Valve 7 Wait a few minutes to ensure all water has completely drained from unit 8 Clean the filter Inspect the water filter located within the cold inlet With a tiny brush clean the water filter of any debris which may have accumulated and reinsert the filter back into the cold water inlet 9 Securely screw the drain plugs back into place Hand tighten only 69 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Components diagrams 13 Case assembly 2 0 70 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Burner assembly T D2 IN OS Burner assembly Power control section Sy gt POONA Fan motor section for OS models 71 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 T D2 IN OS L D e c O O assembly Water way assembly IN OS T D2 Water outlet section Water inlet section Exhaust section OS model 12 CONF
24. Yellow Blue 13 to 17 VDC Input Orange Blue 2 0 to 6 5 VDC Input Verify the fan motor speed using the Diagnostics M ode of White Blue the TM RE30 temperature remote controller See Section 12 1 for details Color Number of wires Fan damper 115 9001 The fan damper is not included in L6 1 2 WE y PWN turbo fan motor EKK25 GONM WAS FEE AE eni de 2 1 m L 5 3 8 137 4nm PWN multi blade fan motor CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 4 Gas valve assembly Included EKH6T LP model Unit Part Takagi Part Checkpoint in 102 EKK5K NA model Opens and closes the gas pathways of the water heater main and solenoid Function gas valves odulates the gas flow from the gas inlet proportional gas valve 1 Gas leak from the valves Failure events 2 Unable to open close main and solenoid gas valves 3 Unable to modulate the gas flow proportional gas valve 1 Gas leak from the unit 2 Excess carbon monoxide emissions No flames 3 Lack of water temperature control Error codes when the 111 121 510 701 valves fails 1 Visual inspection connection breakage of wires
25. board if high voltage gets applied to the eran unit The computer board can short out stopping all operations fails 2 The unit cannot operate because the absorber shorted out causing the fuse to break open surge box falls 1Visual inspection burn marks components and or Diagnostic connection breakage of wires 2 Check resistance and voltage proper range of values shown below Color Number of wires W hite Black 108 to 132 VAC Effects on the water Y Surge absorber A 220 V L 2 3 4 70nm Surge absorber B 680 V 25mm 13 6nmo 43 2MM l 3 4 1 2 32 31 35 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 11 Fault Analysis amp Specifications Remarks 1 Proper range of values of voltage amp resistance shown below 2 Please refer to the wiring diagram for checkpoint positions 3 Remove power to the water heater when checking for continuity disconnections resistance values etc Check Natural of Fault Diagnosis point No display on f 1 Check the power supply 1 Check the power supply from Power ON OFF switch to the PCB Refer to section12 2 controller even when 12 check the power sup
26. desired value 6 After gas pressure has been set deactivate the T D2 IN or T D2 OS remove the manometer tube and replace the port screw Adjusting minimum manifold pressure 1 Ensure that T D2 IN or T D2 OS is not in operation 2 Remove the screw off the manifold port of the T D2 IN or T D2 OS Figure 1 3 Connect a manometer to the manifold port using a tube Figure 2 Ensure that this connection is secure enough to prevent gas leak 4 Run water through the T D2 IN or T D2 OS to activate its operation If presence of a gas leak is detected immediately shut off the T D2 IN or T D2 OS and inspect the tube manifold connection otherwise proceed onto the next step 5 Press and hold down the MIN button on the computer board While holding down the MIN button press either the Increase or Decrease button to increase or decrease the manifold gas pressure respectively Figure 3 Refer to the manometer to verify that pressure has been set to desired value 63 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 6 After gas pressure has been set deactivate the T D2 IN or T D2 OS remove the manometer tube and replace the port screw Figure aN DIK PARENT ele e 310834
27. the cold water inlet is clean hot water at the fixtures enough available when fixture is opened 4 Check whether the hot water fixture is sufficiently open to draw at least 0 5 GM through the water heater 36 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Natura of Faulk The hot water is not gt Check that the filter on the cold water inlet is clean 6 Check whether or not the unit is frozen llable wh fixt e STS 7 Check if there is enough gas in the tank for propane units is opened The hot water turns cold 1 Check whether the flow rate is high enough to keep the water heater running 2 Check if there is a recirculation system installed and check also if the recirculation line has enough check valves 3 Check that the filter on the cold water inlet is clean 4 Check that the fixtures are free from debris and obstructions The fan motor is still L This is normal operation After operation has stopped the fan spinning after operation motor keeps its running 15 to 70 seconds in order to re ignite d quickly as well as purge all the exhaust gas out of the flue as stoppe and stays cold Abnormal sound from 1 Check the gas type of the water heater 2 Check how long the water heater has been installed and in use 3 Check the installation place 4 Check the altitude elevation of area of where the water heater installed 5 Check the vent length when the wa
28. the inlet pipe For the outlet pipe For the inlet pipe d For the heat exchanger w Part 415 EKK2P Part 414 EKK2R 13 330mm 4 3 8 110mm gt de S ATA aan 3 1 2 9ONM 1 8 180nm 7 30 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 15 Computer board Unit Part 701 Takagi Part 439 Checkpoint Controls the functions of most of the parts in the water heater alfunctioning computer A component s may not operate within the water heater In most cases of computer board failure the whole the water heater does not operate at all Error codes will display Error codes when the 701 721 741 761 computer board fails Visual inspection connection breakage of wires and or burn marks on the Diagnostic computer board Effects on the water heater if the computer board fails m 5 1 AAA QAO 8 AA A p Os 3
29. 01 10 78
30. 194 203 212 C 50 55 60 65 70 75 80 85 90 95 100 Temperature fF vs Resistance kQ 25 00 20 00 k isitance 10 00 Res 5 00 0 00 20 40 60 80 100 120 140 160 180 200 220 Temperature F Temperature C vs Resistance kQ 25 00 20 00 2 Resisitance 5 00 0 00 Temperature C 14 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 9 Operational flow chart The diagram below refers to both the T D2 IN and T D2 OS Power supply ON FAVSBV open Y CQperati SW NX Renove cause NORMAL YES C Faucet opens Cpearti on ati stop gt Fal se Di psw t ch gt 031 bl ink setti ngs NTH failure 321 bl i nk Mater Fl ow
31. 2 1121 1135 114 6 1 1 OFF 158 ON OFF OFF OFF 170 2 99 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 9 Multi unit system ON OFF conditions In an Easy Link system the amount of T D2 IN or T D2 OS called on to activate depends on the FLOW RATE and the SET TEM PERATURE 1 Condition required to activate an additional T D2 IN or T D2 OS Flow rate required to activate additional T D2 IN or T D2 OS A xn Where n number of currently activated T D2 IN or T D2 OS and A is dependent on the set temperature See table below Set temperature Factor A GPM 140 158 167 70 75 176 185 80 85 2 Condition required to reduce the number of activated T D2 IN or T D2 OS A In the case of reducing down from two units of T D2 IN or T D2 OS to one unit of T D2 IN orT D2 0S Flow rate A 1 7 B All other cases Flow rate A n 2 3 Example Set temperature 122 F in a four unit system and priority unit is No 1 To activate additional To reduce number of activated T D2 IN or T D2 OS T D2 IN or T D2 OS Flow rate Flow rate Unit No Unit No GPM L min GPM L min 3 0 No 4 OFF 26 No 3 OFF 13 No 2 OFF 7 6 No 1 OFF 1 5 60 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 10 High Altitude Region Support Functions FM FM and FM Using these functions The high altitude region support functions have four operation
32. 2 3nm The burner damper is not included in EKH5W 5 1 4 10 2 Gas manifold Included EKHOT LP model Unit Part Takagi Part Checkpoint N A in 102 EKK5K NA model 1 The manifold distributes gas from the gas valves to the burners The Function Fallure events Effects on the water heater if the manifold fails CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 manifold has two types of the nozzles one type for gas rich burners 16 nozzles and the other for air rich burners 15 nozzles 2 There are 3 zones within the manifold to ensure efficient combustion operation 1 Dust deposit on the manifold 2 Gas leakage from a failed manifold 3 Ignition failure 4 Imperfect combustion 1 The burners cannot receive proper gas flow from the manifold which can cause poor combustion in the combustion chamber In this case the AFR rod will detect an improper flame condition and computer will take safety measures 2 Gas leakage from the manifold Error codes when the manifold fails Diagnostic Color Number of wires 9 1 8 232mm 1 Visual inspection Excessive dust deposit around the nozzles or cracks on the manifold 2 Check voltages and resistance proper range of values shown below Blue Red 78 to 100 VDC 0 9 to 1 7 ko EKHOT for LP model and EKK5K for NA model is an assembly of the gas manifold with the gas
33. 41 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Diagnosis Checkpoint 1 AFR rod fault Refer to section 10 6 Visual inspection connection breakage of wires soot on it 1 Flow sensor failure Refer to section 10 9 Visual inspection connection breakage of wires and or debris on impeller Check voltage resistance between red amp black or white black Malfunction description Cancellation method Fault of driving circuit for main gas solenoid valve MV SV SV and or SV3 The computer checks the condition of the main gas valve immediately after every operation and the conditions of the solenoid valves 6 hours Turn off the power supply after every operation 1 PCB and or main gas valve fault Refer to section 10 4 amp 10 15 V isual inspection of gas valves connection breakage of wires Normal 78 to 100 VDC between COM blue 3 light blue during operation Normal 78 to 100 VDC between COM blue amp 9 green during operation Normal 78 to 100 VDC between COM blue amp 53 orange during operation Normal 78 to 100 VDC between COM blue amp 73 red during operation Visual inspection of PCB connection breakage of wires and or burn marks on the computer board 2 Gas solenoid valve fault MV SV SV and or SV 42 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 if 1 PCB and fan motor fault Refer to section 10 3 amp 10 15 Visual ins
34. 7 8 124rm 9 1 2 241mm Top view Bottom view 5 1 4 133mm GAS 4 7 8 124nm 13 1 8 334mm V V V V 164nm gt 7inm 99mm 135nm 12 0 3 7 gt 6 1 2 gt COLD 2 7 8 GAS 5 1 4 HOT gt P le COLD 3 1 4 84nm 120VAC 1 3 8 36mm gt lt i CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 3 Interior view T D2 IN CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 T D2 OS 29 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 4 List of main components in the interior view Items in Common parts Description components for other models diagram EK402 T D2 IN Case assembly 001 EKK41 T D2 OS T K30S l Manifold assembly with EKH6T LP model T H2 DV OS gas valve assembly EKK5K NA model 3 Computer board 7 439 T K3 T K3 Pro T K3 SP OS 4 Igniter EKN 74 T H2 DV OS T KJr2 IN OS T K4 IN OS T M50 T M 32 1 102 0 71 702 09 T K3 T K3 Pro T K3 SP OS T K3 T K3
35. AFR rod detects unexpected flame conditions the computer of the water heater makes adjustments in the fan motor speed to compensate 1 Unable to detect flames when flames actually do occur Failure events 2 Detecting a false flame when no flames actually occur 1 The water heater will not initiate the ignition process The 721 error Effects on the water code will display heater if AFR rod fails 2 The fan motor speed cannot be modulated properly under abnormal flame conditions which can result in excessive CO emission Error codes when the 101 391 991 AFR rod fails 1 Visual inspection connection braking of wires soot on it 2 Check voltages proper range of values are shown below Yellow 8 AFR rod Between AFR rod and the During operation More than DC 0 5 pA Diagnostic Color Number of wires computer board The AFR rod is assembled with the flame rod Detecting elements AFR and flame rods gt st st lt m H 1 1 8 29 3nm Leads to computer board Fl ame rod 3 4 17 5nm L A 1 2 12mm 22 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 7 Heat exchanger 0002 IN Unit Part 401 Takagi Part Checkpoint N A EK437 OS Absorbs heat from combusti
36. B connection breakage of wires and or burn marks on the computer board Visual inspection gas proportional valve connection breakage of wires of the gas proportional valve Normal 20 to 40 O between white amp red Malfunction description Cancellation method False flame detection Turn off the power or water supply 721 Diagnosis False flame detection 5 sec Flame rod Insulated resistance fault Malfunction description Cancellation method Restoring proper cable connections between the water heater and the Remote controller TM RE30 When the computer detects proper connections between the water heater and the remote controller 741 error code will cease to display Diagnosis 1 Temperature remote controller TM RE30 or PCB fault 2 Check for signs of power surges Miscommunication between water heater and temperature remote controller 44 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Malfunction description Cancellation method Restoring proper cable connections among all the water heaters When the computer detects proper connections among all the water heaters 761 error code will cease to display Diagnosis 1 Inspect cable connections between Parent and Child units 2 Check for signs of power surges Miscommunication between Parent and Child units for Easy Link systems Malfunction description Cancellation method Turn off the power or water supply Imperfect combustion If
37. CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 T D2 IN T D2 OS On Demand Water Heater Service M anual A O Smith Water Products Company 500 Tennessee Waltz Parkway Ashland City TN 37015 Toll Free 1 877 737 2840 Table of Contents e e Ae BA BPA pp B W N F O A A A o re e E io E Exterior view Interior view List of main Nim in the interior view Schematic diagram Wiring diagram ia W iring diagram E Operatlonal TOW COMPONENT SS CIC ONG b tds Fault Analysis S 6 2322095 aa o e e O OR en s COMPONEN QJIN G ainas a IS y REVISION Sa tia CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 1 Specifications Dimensions CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 H20 5 XW13 8 xD8 5 39 Ibs Water control 5 y e Features Weight INPUT Max 199 000 BTU h Min 11 000 Combustion Svstem Power vent Installation Indoor amp Direct vent Outdoor Fan motor Manifold Pressure Flow rate PWM turbo fan LP 3 5 WC Natural 2 0 WC Natural 0 4 WC PWN multi blade fan motor LP 4 4 WC Natural 2 8 WC LP 0 9 WC Natural 0 5 WC LP 0 7 WC 0 75 to 10 0
38. IDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 14 Parts list Item Part Description Common parts for other models EK402 Case assembly IN T K4 IN T K3 T K3 Pro T K3 SP OS T KJr2 IN OS T K4 IN OS 004 09 Bracket T K3 T K3 Pro T K3 SP OS T H2 DV OS T KJr2 IN OS T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS Junction box inner plate T KJr2 IN OS T K4 IN OS 007 EKK5H Back guard panel T K3 T K3 Pro T K3 SP OS T K4 IN OS 050 000 Screw M 4x12 W Washer 005 Junction box 006 061 EN Tap tight screw M 4x12 FEZN 065 EWOOD Pan screw M 4x8 T K3 T K3 Pro T K3 SP OS T H2 DV OS 066 ECOOX Nylon clamp T KJr2 IN OS T K4 IN OS T M 32 73 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Item Part Description Common parts for other models T K3 T K3 Pro T K3 SP OS T H2 DV OS Wire clamp 60 T KJr2 IN OS T K4 IN OS T M 50 T M 32 067 EM 167 101 EKH5W Burner assembly T H2 DV OS T K4 IN OS T EKH6T Manifold with gas valve assembly LP T H2 DV OS T K4 IN OS EKK5K Manifold with gas valve assembly T K4 IN OS T K3 T K3 Pro T K3 SP T H2 DV OS T K4 IN EKK25 Fan motor IN 103 T M 50 T M 32 EKK54 Fan motor Out T K3 OS T K4 OS T K3 T K3 Pro T K3 SP OS T H2 DV OS 104 EKKOG Burner holder gasket T K4 IN OS T M 50 T K3 T K3 Pro T K3 SP OS T H2 DV OS 105 EKK2X Burner gasket
39. In the T K3 SP OS Vi cel Sour Red VCC 25 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 10 Bypass valve Unit Part Takagi Part EKKOU Checkpoint EE 1 Mixes hot water from the heat exchanger with cold water from the water inlet in order to modulate and control the water heater s outlet water temperature 2 Keeps the water temperature in the heat exchanger stable preventing low temperature corrosion by reducing condensation buildup in heat exchanger 1 Water leakage from valve Failure events 2 The valve cannot modulate properly 1 Water leakage from failed valve can damage other water heater components 2 Temperature fluctuations in the hot water output Error codes when bypass N A valve fails 1 Visual inspection connection breakage of wires 2 Check voltages and resistance proper range of values shown below Color Number of wires Red Black 7 to 16 VDC and 0 09 to 0 2 ka The physical appearance of the bypass valve is similar to that of the flow adjustment valve However their functions differ and cannot be substituted for each other Function Effects on the water heater if bypass valve fails Diagnostic SSS NS N 2 5 8 _ 67 5nm SSNSNNNNNN 84 4mm 3 3 8
40. N T D2 OS Service M anual Ver 1 00 10 1 Burners Unit Part 101 Takagi Part EKH5W Checkpoint There are 2 types of burners in the water heater the gas rich burner stabilizes the flames within the combustion chamber and the air rich burner Function produces more heat in the combustion chamber The burners facilitate the air gas mixture necessary to produce the proper heat during the combustion reaction 1 Unable to initialize sustain combustion 2 Dust or soot deposit on the burner surface 3 Cracks on the burners Failure events 4 Gas leakage from the burners 1 Unexpected combustion Effects on the water 2 Unstable flame conditions and or flame loss heater if burners fails 3 Ignition failure 4 Back firing Error codes when the burners fails Visual inspection excessive dust deposit on the burner surface and or Diagnostic unstable flame conditions during operation 139 6nm 7 1 2 Burner damper 112 EK412 7 7 8 201mm Ll 3 4 440mm 13
41. NFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 5 Flame rod Unit Part 108 Takagi Part EKKOE Checkpoint To detect flames while the water heater is in operation 1 Unable to detect flames when flames actually do occur Failure events 2 Detecting a false flame when no flames actually occur 1 The water heater stops operating The 111 and or 121 error code s Effects on the water will display heater if flame rod fails 2 The water heater will not initiate the ignition process The 721 error code will display Error codes when the 111 121 721 flame rod fails 1 Visual inspection connection breakage of wires or soot buildup on rod 2 Check Amperes proper range of values shown below Orange 17 Flame rod Diagnostic During operation Color Number of wires Between flame rod and the More than DC 1 uA computer board The flame rod is assembled with the AFR rod 2 FR Detecting elements of the flame rod 29 3nm gt 1 1 8 L TF SS Leads to computer board 3 4 17 5nm Fl rod 21 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 6 AFR rod Unit Part 108 Takagi Part EKKOE Checkpoint Checks flame conditions during combustion Function When
42. OR Output temperature is over 194 F OR The water flow rate is less than 0 4 GPM 56 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 7 B ON OFF conditions BTU requirements A Calculating the ON OFF conditions of the T D2 IN or T D2 OS Condition needed to turn the T D2 IN or 02 05 ON Ts Tin x500 gt 14 880 Condition needed to turn the T D2 IN or T D2 OS OFF x 500 lt 11 900 Or Tin jen Where Tse Set temperature and Tin Inlet temperature B Calculation example Set temperature Tse 122 F Flow rate 2 5 GPM Condition needed to turn the T D2 IN or 02 05 ON 122 Tin x2 5 x500 gt 14 880 Tin lt 110 1 F Condition needed to turn the T D2 IN or T D2 OS OFF 122 Tin x2 5 x500 lt 11 900 Tin gt 112 5 F The output temperature at that moment will be 120 F C ON OFF table Set temperature Flow rate GPM F 0 5 1 0 2 5 3 0 3 5 1 5 2 0 4 0 14 4 98 2 106 1 110 1 112 5 114 1 115 2 116 0 N O 1 1 1 1 1 1 9 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 8 A Pump control ON OFF Conditions Only for single and Easy link system To run circulation pumps efficiently and effectively the T D2 IN T D2 OS offers mode of pump control The following table shows the pump contro ON OFF conditions Re circulation mode These functions enable the re circulation pump to be controlled by
43. OS 413 EK333 Overheat cut off fuse T K4 IN OS T M 50 T K3 T K3 Pro T K3 SP OS T KJr2 IN OS T K4 IN OS T K3 T K3 Pro T K3 SP OS T H2 DV OS T KJr2 IN OS T K4 IN OS T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS T KJr2 IN OS T K4 IN OS T M 50 T M 32 T H2 DV OS r2 IN OS T K4 IN OS T M 50 45 EK031 Heater fixing plate 16 T M32 o T K3 T K3 Pro T K3 SP OS T H2 DV OS 452 EKK26 Fuse fixing plate 18 T KJr2 IN OS T K4 IN OS T M 50 T M 32 o T K3 T K3 Pro T K3 SP OS T K r2 IN OS 453 029 Fuse fixing plate 14 T K4 IN OS T K3 T K3 Pro T K3 SP OS T H2 DV OS 454 EZM 04 O ring P4 FKM T KJr2 IN OS T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 455 EZM 06 O ring P6 FKM T KJr2 IN OS T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 456 EZM 14 O ring P14 FKM T KJr2 IN OS T K4 IN OS T K3 T K3 Pro T K3 SP OS T H2 DV OS 457 EZM 15 O ring P15 FKM T KJr2 IN OS T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 458 EZM 16 O ring P16 FKM T KJr2 IN OS T K4 IN OS T M 50 T M 32 459 EKH30 Fastener 4 11 T K3 T K3 Pro T H2 DV OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 460 EKK24 Fastener 14 22 T KJr2 IN OS T K4 IN OS 76 414 EKK2R Heater 415 EKK2P Inlet heater 450 EKK27 Pipe heater fixing plate CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Item Part
44. S is in operation set dipswitch No 3 to the ON position Figure 1 2 On the temperature remote controller display mode 48 fan motor speed by entering the Diagnostics mode Refer to Section 12 1 3 Press and hold down the MAX button on the computer board While holding down the button press either the Increase or Decrease button to increase or decrease the fan motor speed respectively Figure 2 Refer to the remote controller display to verify that soeed has been set to desired value 4 After fan speed has been set set dipswitch No 3 back to the OFF position Adjusting minimum fan motor speed 1 While T D2 IN or T D2 OS is in operation set dipswitch No 3 to the ON position Figure 1 2 On the temperature remote controller display mode 48 fan motor speed by entering the Diagnostics mode Refer to Section 12 1 3 Press and hold down the MIN button on the computer board While holding down the MIN button press either the Increase or Decrease button to increase or decrease the fan motor speed respectively Figure 2 Refer to the remote controller display to verify that soeed has been set to desired value 4 After fan speed has been set set dipswitch No 3 back to the OFF position Upper bank of dipswitch settings Figure 2 MAX button MIN button Increase button F
45. T KJr2 IN OS T K4 IN OS T K3 T K3 Pro T K3 SP OS T H2 DV OS 106 EKK2V Burner window T KJr2 IN OS T K4 IN OS T M 50 T M 32 T H2 DV OS T KJr2 IN OS T K4 IN OS T M 50 107 EKK2W Rod holder gasket T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 108 EKKOE Flame rod T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 109 EKKOF Igniter rod T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 110 EKK32 Rod holder T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 111 EKN61 Rod cap T KJr2 IN OS T K4 IN OS T M 50 T M 32 T K3 T K3 Pro T K3 SP OS T H2 DV OS 113 EKK2Y Manifold gasket A T KJr2 IN OS T K4 IN OS T M 50 T K3 T K3 Pro T K3 SP OS T H2 DV OS 114 EKK2K Manifold gasket B T KJr2 IN OS T K4 IN OS T M 50 T K3 T K3 Pro T K3 SP T H2 DV OS 116 EKK2D Pressure port T K4 IN OS T M50 T M 32 74 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Item f Part Description Common parts for other models EKK2N Combustion chamber tube In T K3 T K3 Pro T K3 SP T H2 DV OS T K4 IN 117 EX019 Combustion chamber tube Out T K4 OS T M 50 T K3 T K3 Pro T K3 SP OS T H2 DV OS 8 EKKIE Gas inlet EKK2Z Gas inlet ring 120 EKKIB Igniter plate 1 14 T KJr2 IN OS T K4 IN OS T K3 T K3 Pro T K3 SP OS T H2 DV OS 1 14 co T KJr2 IN OS T K4 IN OS T K3 T K3 Pro T K3 SP OS T H2 DV OS T KJr2 IN OS
46. White during Easy link operation Mixing thermistor Black Black Black Black See table on p 11 Black Black Light blue blue at COM M V Green blue at COM SV1 C Gas valves Orange blue at COM SV2 Red blue at COM SV3 Output thermistor 110 to 160 VDC G Fan motor 13 to 17 VDC 2 to 6 5 VDC CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Check 22 Part and Description Colorof wires Normal range poin 1 to 15 VDC during operation Gas proportional valve White red and 2010400 Red Black 4 to 5 5 VDC to 4 VDC pulse Flow sensor White Black 1 080 pulse min more than 18 Hz Yellow AFR rod More than 0 5 pA Air fuel ratio rod Between AFR rod and during operation the computer board Orange Flame rod Flame rod Between flame rod and the computer board 7 to 16 VDC and Flow adjustment valve Red Black 0 09 to 0 2 7 to 16 VDC and More than 1 u A during operation Bypass valve Red Black 0 09 to 0 2 ka K Pump connector port White Black Less than 1 3 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 8 Resistance values of the temperature thermistors The T D2 IN and T D2 OS use the same thermistors Resistance values at different temperatures 2F 32 41 50 59 68 77 86 95 104 113 Temperature C 0 5 10 15 20 25 30 35 40 45 Temperature 2F 122 131 140 149 158 167 176 185
47. al 0 9 to 1 7 kQ between COM blue 73 red 6 Fault of PCB in the water heater No voltage flow adjustment valve Normal 7 to 16 VDC between red black 7 Flow adjustment valve fault Normal 0 09 to 0 2 kQ between red black Malfunction description Cancellation method Incorrect dipswitch setting fault Turn off the power or water supply of hot water temperature Diagnosis Check the dipswitch settings on PCB MI Malfunction description Cancellation method Warning for the 991 error code On ue PP aie EC Refer to section 12 3 buttons simultaneously for 3 sec Then turn the power off 1 Check the gas type of the water heater 2 Check how long the water heater has been installed and in use 3 Check the installation location 4 Check the altitude elevation of area of where the water heater installed 5 Check the vent length 6 Check if there is any blockage in the intake air and or exhaust 7 Check if there is dust and lint in burner and heat exchanger when the water heater has been installed in laundry room 38 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 8 Check if there is grease and dirt in burner and fan motor when the water heater has been installed in restaurant 9 Check the manifold pressure in the water heater 1 Check gas supply and inlet gas pressure Refer to section 1 2 Check the igniter Refer to section 10 17 Visual inspection connection breakage of wires and
48. e 101 error code speed is automatically decreased and AFR combustion stage goes down 6 Default 7 to 16 Gas rich or Air shortage In order to solve the air deficiency problem the fan motor speed is automatically increased and AFR combustion stage goes up 0 iti Default condition 15 101 error code H 16 991 error code When the 101 or 991 error code appears see section 12 3 LI LI LI 9 92 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 5 Dipswitch settings Upper bank of dipswitches The T D2 IN shares the computer board with the T D2 OS The computer board has two bank of dipswitches upper and lower The upper bank has certain special functions as shown on the following table and generally should not need adjustment Carefully verify the functions of each dipswitch before changing any settings Lower bank of dipswitches The functions of the upper bank of dipswitches No Functions ON position OFF position Allow adjustments of fan motor speed Enable Disable Changing the FM speed is similar to changing the Default manifold pressure See section 12 13 FM FM and FM FM speed is increased automatically See section 12 10 T D2 IN ie OFF position ON position
49. e numbering of units Unit s can be reset and reassigned manually 1 Press and hold the Increase button on the computer board of all child units for at least 5 seconds 2 The 7 seg LED on the computer board of all child units will display 0 to signify that the computer memory has been erased of its previously assigned unit 3 Press and hold the Increase button on each unit in the new order of your choosing The new unit numbers will be assigned in this order Each T D2 IN or T D2 OS in an Easy link system is assigned a random unit except forthe Parent unit which is always assigned as unit 1 e When more than four units of the T D2 IN or T D2 OS are connected in an Easy link system only the first four units will work as a system The remaining units will not operate Increase button 7 seg LED Computer board 55 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 7 A ON OFF conditions Overview The following table shows the ON OFF conditions of the water heater ON OFF Conditions The BTU requirement is more than 14 880 BTU h Conditions needed to turn ON AND The water flow rate is more than 0 75 GPM The BTU requirement is less than 11 900 BTU h OR Inlet temperature is higher than the set temperature Conditions needed to turn OFF
50. e rod wire orange 5 Disconnected damaged O H C F Refer to section 10 13 Error code is Visual inspection connection breakage of wires Normal 1 0 or less between blue amp blue 6 Check if hi limit switch is properly functioning 7 Disconnected damaged hi limit switch Refer to section 10 12 Visual inspection connection breakage of wires ignition Normal 1 0 or less between blue amp blue Malfunction description Cancellation method Mi Disconnected short circuited output thermistor Turn off the power or water supply shown after three failed attempts at 1 Output thermistor fault Refer to section 10 11 Visual inspection connection breakage of wires and or debris on E2 thermistor Check voltage resistance between black amp black 12 Refer to Section 8 for proper range of values Disconnected short circuited inlet thermistor Turn off the power or water supply 1 Inlet thermistor fault Refer to section 10 11 Visual inspection connection breakage of wires and or debris on E3 thermistor Check voltage resistance between black amp black 42 Refer to Section 8 for proper range of values Disconnected short circuited mixing thermistor Turn off the power or water supply 1 Mixing thermistor fault Refer to section 10 11 Visual inspection connection breakage of wires and or debris on El thermistor Check voltage resistance between black amp black 113 Refer to Section 8 for proper range of values
51. eck the connection of ground wire make sure there is firm contact to attempts at the ground of the water heater ignition in this case the wire is contacted to the manifold surface 3 PCB fault During operation more than 1 yA through the flame rod wire orange 4 Flame rod fault During operation more than 1 yA through the flame rod wire orange shown after three failed 8 Check if hi limit switch is properly functioning 1 Check gas supply and pressure Refer to section 1 2 PCB fault 1 No voltage to gas main solenoid valve Error code is Normal 78 to 100 VDC between COM blue 3 light blue shown after during operation 2 No voltage to gas solenoid valve SV Normal 78 to 100 VDC between COM blue amp 53 orange during operation ignition 3 No voltage to gas proportional valve VGo Normal 1 to 15 VDC between white amp red during operation 3 Gas solenoid fault 1 Main gas solenoid valve M V fault Normal 0 9 to 1 3 kO between COM blue amp 3 light blue 2 Gas solenoid valve SV fault Normal 1 3 to 1 9 kO between COM blue 53 orange 3 Gas proportional valve VG fault Normal 1 to 15 VDC between white amp red three failed attempts at 40 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Error Code Diagnosis 4 Check for soot on the flame rod 1 Clean the flame rod 2 PCB fault During operation more than 1 yA through the flam
52. er heater cannot ignite during the ignition process and the 111 Effects the water or 121 error codes will display heater if the igniter fails 2 No effects on the water heater however the durability of the igniter wears down Failure events 1 Visual inspection connection breakage of wires and or an observed weak Spark 2 Check voltages proper range of values shown below The high voltage igniter cable and the purple wires High voltage igniter cable do not come ae with EKN74 Purple wire 90 to 110 VAC 1 3 44nm b To Hi gh i gnite cable Power supply AC 90 to 110V 33 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 18 Freeze protection thermostat 713 59 IN Unit Part Takagi Part Checkpoint 710 EKK40 OS Temperature detecting device which prevents the pipes within the water heater from freezing When this device detects temperatures below 36 5 F 2 5 C inside the water heater power is supplied to the electric heaters to prevent the water heater from freezing 1 ON failure Always senses freezing temperatures regardless of actual Failure events temperature 2 OFF failure Never senses freezing temperatures
53. fer to the table on p 48 for the proper mode 6 Press the INFO button to select the mode and information to which the mode correlates to will display on the TM RE30 Fig 4 7 When the ON OFF button is pressed or 5 minutes have elapsed without pressing any buttons the display will return to normal Whole diagnostic mode Information Fipl Fig 2 For example the figures above show how to arrive atthe ON OFF cycles information for Unit 2 in a Easy Link System 48 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Description of mode numbers in Diagnostics M ode Total system flow rate Whole multi unit system information 0 0 to 999 x0 1 Unit information 1 to 4 Total operation time 0 to 9999 hours N A ON OFF cycles 0 to 9999 x100 cycles Quantity of connected 1 to 4 units Fan motor speed 0 to 9999 rpm 1 to 4 unit H Inlet temperature Quantity of operational T D2 IN or T D2 OS s to 4 units Output temperature Set temperature 99 to 185 F Mixing temperature 32 to 210 F Over 210 F2E5 Under 32 F E0 Operation time during current rotation 0 to 720 minutes After 720 the rotation occurs ratio to 999 0 1 ON OFF cycles during current rotation 0 to 100 cycles After 100 the rotation occurs nextiFlow rate Energization time of unit 0 to 999
54. he information to which the mode correlates to will display on the TM RE30 Fig 2 4 When the ON OFF button is pressed or 5 minutes have elapsed without pressing any buttons the display will return to normal INFO BUZZER ON OFF Button Button Button Information Fig 2 47 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 lt For multiple units in an Easy Link system gt 1 Press and hold the HOT and COLD buttons simultaneously for at least 5 seconds to enter Diagnostics M ode 2 0 will be displayed on the TM RE30 See Fig 1 3 Scroll to the desired T D2 IN or T D2 OS unit fin the easy link system by pressing the HOT or the COLD buttons to scroll up or down Fig 2 shows that unit 2 is being selecting NOTE The definition of the unit 5 0 will yield information about the Easy link system as a whole and numbers 1 42 3 4 will yield information about each of the individual T D2 IN or T D2 OS installed in the Easy link system In an Easy link system of T D2 IN or T D2 OS a maximum of four units of the T D2 IN or T D2 OS s can be linked together 4 Press the INFO button to select the desired unit 5 When the desired unit 15 selected and fixed scroll up or down to the needed information mode of the unit by pressing the HOT or COLD buttons Fig 3 shows mode 46 is being selected When selecting information please re
55. igure 1 Decrease button The dark square is the direction the dipswitch should be set to Computer board 65 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 14 Freeze protection system There are two features to the T D2 IN or T D2 OS s freeze protection system the automatic firing system and the ceramic heating blocks The automatic firing system allows the T D2 IN or T D2 OS to briefly fire on for about 4 seconds and the ceramic heating blocks will heat up whatever portion of the heat exchanger the blocks are strapped to The firing system mainly focuses on providing freeze protection around the heat exchanger pipes The three heating blocks focus on protecting the inlet and outlet piping inside the T D2 IN or T D2 OS as well as the front drum pipe The conditions to activate either feature are different from each other However the two features are not mutually exclusive because they focus on different areas of the T D2 IN or T D2 OS As long as each particular feature s activation requirements are met it is possible for both features to operate at the same time Automatic firing system Activation conditions will depend on the on whether or it is an indoor direct vent or outdoor installation Gasand electrical power are required for this feature to operate T D2 IN installation After 5 minutes have elapsed since the T D2 IN or T
56. ill e Manifold port Figure 2 Tube TA 2 PUMP D f PARENT a Figure 3 M AX button To Manometer MIN button Increase button Decrease button Computer board 64 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 13 Manually adjusting the fan motor speed While the FM dipswitch will automatically increase the fan speed the fan motor speed on the T D2 IN or T D2 OS can also be manually adjusted In order to perform manual adjustments to the speed a TM RE30 remote controller is required intake air for combustion which can cause excess CO emission from the exhaust chamber if the fan motor speed is set incorrectly Therefore this procedure should never be WARNING performed unless the Technical Services Department has given consent and authorization anually adjusting the fan motor speed of the T D2 IN or T D2 OS will change the amount of Adjusting maximum fan motor speed 1 While T D2 IN or T D2 O
57. let thermistor and Tout is the temperature of the output thermistor To sum it up in a chart Case 25 minutes have elapsed Inlet thermistor Output thermistor Will automatic since prior operation temperature temperature firing be activated 1 No Any Any NO 67 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Ceramic heating blocks The blocks will only activate based on what the freeze protection thermostat senses The thermostat is located on the fan motor close in vicinity to the inlet and outlet pipes within the T D2 IN or T D2 OS Electrical power is required for this feature to operate The heating blocks will activate if the thermostat senses a surrounding temperature below 36 5 F Once they are on the heating blocks will only deactivate if surrounding temperatures reach above 46 4 F 68 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 15 Draining and cleaning the inlet water filter 1 Close the manual gas shut off valve a A 2 Turn off power to the T D2 IN or T D2 OS wait a few seconds And then turn on again 3 Wait 30 seconds for water valves starts to completely open Then turn off power to the T D2 IN or T D2 OS yet again 4 Close the water shut off valve ET 2 al f 5 Open all hot water taps in the house When the all water flow has ceased close all hot water taps ga lt A 1 va Ire Bl Y j EE TIN IS ALAS Gas
58. n below Color Number of wires Blue Blue Less than 1 0 0 Diagnostic Solder will melt at temperature exceeding 430 F 49 F or 221 F 45 C 5 1 32 127 8 mm The O H C F has a red line on itself 29 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 14 Freeze protection heaters 414 EKK2R Unit Part Takagi Part Checkpoint Bl 415 EKK2P Prevents the heat exchanger water valves and water pipes within the water Function heater from freezing The heaters are but one of the freeze protection devices in the water heater Open circuit failure Ceramic heaters do not receive the voltage needed to Failure events heat up Effects on the water Ceramic heaters do not activate allowing water contained in the heat heater if heater fails exchanger to freeze up possibly causing the heat exchanger to burst Error codes when N A heaters fails 1 Visual inspection connection breakage of wires and the condition of the heaters Diagnostic 2 Check whether those are in the normal range as shown in the following table Color Number of wires Black Black 90 to 110 VAC during freeze protection operation The water heater has two types of the heaters in it The one is for protecting of the heat exchanger and the outlet pipe the other one is for protecting of
59. nditions BTU 57 12 8 A Pump control ON OFF conditions Only for single and Easy link system 58 12 8 Pump control ON OFF conditions BTU requirements eene 59 12 9 Multi unit system ON OFF mmm nmm mne 60 12 10 High Altitude Region Support Functions FM FM Hand eem Re Ol 12 11 Relay selection for the pump control mmm 62 12 12 Adjusting manifold Qas pressure 12 13 Manually adjusting the fan motor speed sssememenemenzmenzmnimemimenememimimamimenznnninzz OD 12 14 Freeze protection system e sisse mmm mmm meme meme emnes OO 12 15 Draining the unit and cleaning the inlet water filter sese 09 46 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 1 Diagnosis using the TM RE30 Individual unit 1 Press the HOT button and the COLD button simultaneously for at least 5 seconds to enter Diagnostic mode HOT 2 Scroll up or down to the needed information mode of the TIME Button COLD T D2 IN or T D2 OS by pressing the HOT or COLD buttons Fig 1 shows mode 5 being selected When selecting information please refer to the table on p 49 for the proper mode Press the INFO button to select the mode and t
60. not possible press and hold the INC Refer to section 12 3 and DEC buttons on the computer board simultaneously for more than 3 sec Diagnosis 1 Check the gas type of the water heater 2 Check how long the water heater has been installed and in use 3 Check the installation place 4 Check the altitude elevation of area of where the water heater installed 5 Check the vent length 6 Check if there is any blockage in the intake air and or exhaust 7 Check if there is dust and lint in burner and heat exchanger when the water heater has been installed in laundry room 8 Check if there is grease and dirt in burner and fan motor when the water heater has been installed in restaurant 9 Check the manifold pressure in the water heater 45 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 Controls and settings 12 1 Diagnosis using the 0 emm mem meme mme 47 12 2 The error code button Verifying functionality of computer board Displaying error code history and Clearing error code history memory eene 50 12 3 Clearing the 101 and 991 error code sees mmm mmn mmm DL 12 5 ER OG FUNCION a 12 5 IDSWIECH SOLU OP eM iden dale ica 22 12 6 Assigning unit numbers in the Easy link system mmm mmm 12 7 A ON OFF conditions Overview essem mmm meme eem memes DO 12 7 B ON OFF co
61. ntrol BTU NO gt change over SV1 5 3 CFF poi nt YES 391 bl ink 991 bl ink 121 blink 121 bli nk A A Abnor nal CHCF nel ted Fl ane er AR Toa burni ng above 430 F blows out heat capability T Bel ow NO Max flowrate 55 52 95 311 blink 321 blink 331 bli nk 611 bii nk YES N FAV OPEN CPEN M TH OPEN Fan not or or SHORT or SHORT or SHORT faut Safety devi p YES lt sensed abnornal conditi on NO 20sec later 15 10 Component specifications 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 10 15 10 16 10 17 10 18 10 19 PUTAO rimi e EE E bon QC UR PA Pe TENE A Gas Valve ests o e e An AFR PP E NE o E Flow AO Simeone FIOW SSIS ON l eng UEM MEN BDA a PA pps l KE nt f ent Freeze protection TIGBEBIS adus iin iaa das COMPU DO METRE mmm e E EE A e A A Freeze protection mmm emm menn WOE JOX sara CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 17 18 19 20 21 22 23 24 25 26 2 28 29 30 31 32 33 34 35 CONFIDENTIAL T D2 I
62. ntrol connection The maximum current capacity of pump control connection in the T D2 is 1 amp Before using any relay with the pump control please check the specifications of that particular relay to ensure that the current value through the coil will not exceed 1 amp Coil Data 25 i For example i Nominal Power Maximum Power ERP 3 IWA Encinsed Models To the right there is a sample of relay FEST aw Cendosed Medels SW oe i i AC FA _ Open Models specifications from an arbitrary brochure You pe EmN per mabik am Open Models AW can select either the 120 VAC or 240 VAC relay Continuous Initial Insulation Resistance KAP KAFA 1000 min because their current values are less than 1A 100 Megohms min 1 000mA Coil Data 25 C E Nominal Resistance 2 Naminal Coil Voltage 10 il Current mA B 32 188 12 120 100 DC pa 472 51 Coils 48 1800 26 6 2 alls Ny yt L E Ni l Power supply I O 9 gp Em EOS OVA p 9 lt 220 VAC etc i l Thermal 120 VAC relay 220 VAC etc for relay 2 These components are NOT included with the water heater and external to the unit They must be acquired separa
63. on and transfer it to water through the heat exchanger pipes 1 Clogged heat exchanger fins and or cracks on the heat exchanger walls Failure events 2 Leaking exhaust gas 3 Improper heat transfer can cause the water in heat exchanger to boil 1 Water leakage from the heat exchanger 2 Exhaust gas leakage if this occurs an overheat cutoff fuse is in place to heater if the heat detect this event and immediately stop the water heater from operating exchanger fails 3 Abnormal sounds during combustion N A heat exchanger fails 1 Visual inspection soot deposits cracks on the heat exchanger walls and or water leakage from the heat exchanger 2 In the event of abnormal sounds during combustion Diagnostic A Inspect for soot buildup inside the heat exchanger B Inspect for scale buildup inside the heat exchanger pipes Scale buildup obstructs proper heat transfer to the water thereby overheating the heat exchanger and causing damage The heat exchanger of the T D2 IN 7 02 05 has the Pro mark as shown below T D2 IN Effects on the water o 475nm 14 3 4 376mm 12 1 4 313mm 00 mM In 0 N 13 3 4 10 5 8
64. or observed weak Spark shown after 1 Cracks soot on igniter rod three failed 2 Improper gap between burner amp igniter rod Normal gap 0 16 4mm 3 PCB fault ignition Normal 90 to 110 VAC at 7 purple purple during ignition 3 PCB fault 1 No voltage to main gas solenoid valve Normal 78 to 100 VDC between COM blue amp 3 light blue during operation 2 No voltage to gas solenoid valve SV Normal 78 to 100 VDC between COM blue amp 53 orange during operation 3 No voltage to gas proportional valve VGo Normal 1 to 15 VDC between white amp red during operation Error code is attempts at 4 Gas solenoid valve fault 1 Main gas solenoid valve M V fault Normal 0 9 to 1 3 between COM blue 3 light blue 2 Gas solenoid valve SV fault Normal 1 3 to 1 9 kO between COM blue 53 orange 3 Gas proportional valve VG fault Normal 1 to 15 VDC between white red during operation 39 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Error Code Diagnosis 5 Disconnected damaged O H C F Refer to section 10 13 Visual inspection connection breakage of wires Normal 1 or less between blue amp blue 6 Disconnected damaged hi limit switch Refer to section 10 12 Visual inspection connection breakage of wires Error code is Normal 1 less between blue amp blue 7 Inspect flame rod 1 Check for any soot on the rod 2 Ch
65. pection of fan motor connection breakage of wires or dust buildup causing electrical shortage Normal 110 to 160 VDC between red amp blue during operation Normal 13 to 17 VDC between yellow amp blue during operation Normal 2 0 to 6 5 VDC between orange amp blue during operation G Verify fan motor speed of the water heater using the diagnostics mode of the TM RE30 temperature remote controller See the 12 1 How to diagnose the water heater using the TM RE30 Visual inspection of PCB connection breakage of wires and or burn marks on the computer board Malfunction description Cancellation method OW eg Sent vale taut Turn off the power or water suppl Only Easy link system 1 PCB and flow adjustment valve fault Refer to section 10 8 amp 10 15 Visual inspection of flow adjustment valve connection breakage of wires motor drive locked due to scale buildup and or water leakage Normal 7 to 16 VDC between black red Visual inspection PCB connection breakage of wires and or burn marks the computer board 43 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Malfunction description Cancellation method 1 PCB fault 1 Fault of preparation for the mixing thermistor operation Turn off the power or water supply 2 Fault of driving circuit for Gas Proportional Valve VG Check the PCB and or gas proportional valve Refer to section 10 4 amp 10 15 Visual inspection PC
66. ply line to the water heater remote isturned on 2 Fault of Power ON OFF switch Normal 100 VAC between white black A Normal 100 VAC between brown brown Al temperature remote 3 Fault of transformer 1 Disconnection breakage of wires Normal 120 VAC between white black A2 Normal 100 VAC between brown brown Al 4 Blown fuse at surge box 3A A2 5 Fault of PCB 1 No voltage at remote control terminal F Normal 11 to 25 VDC between white black 6 Disconnection short circuit grounding of remote wires Normal 11 to 25 VDC between white black 7 Fault of PCB of remote control 1 Check for normal voltage at terminal It takes long time to get 1 The time it takes to deliver hot water from the water heater to fixtures depends on the length of piping between them The longer the distance or the bigger the pipes the longer it will take to get hot water 2 If you need hot water to fixtures quicker you may want to consider a hot water recirculation system The water is not hot 1 Check cross pluming between cold water lines and hot water lines 2 Check whether the gas supply pressure is enough 3 Check whether the temperature setting is too low The water istoo hot 1 Check whether the temperature setting is too high The hot water is not 1 Make sure the unit has 120 VAC 60 Hz power supply 2 If the remote controller is used check whether the power button is turned on 3 Check that the filter on
67. r codes signify imperfect abnormal combustion caused by insufficient intake air and or obstructions in the exhaust A Ifthe 101 and 991 error code occurs please check the following W hat is the gas type of the water heater liquid propane or natural gas How long has the water heater been installed and been in use Where is the water heater installed indoor outdoor attic etc What is the altitude elevation of the area of installation EE cm ES Are there any obstructions in the intake air and or exhaust Damper sticking Vent Flaps installed on the Terminator Snow build up around Terminator Installed in a closet No Ventilation or lack of combustion air 6 If installed in laundry room check the burner and heat exchanger Dust and lint may deposit in burner and heat exchanger 7 If installed in restaurant check the burner and fan motor Grease and dirt may deposit in burner and fan motor 8 Check if the manifold pressure of the water heater is too high B How to clear the 101 and 991 error code after resolving the main root cause of the error On the computer board press and hold the Increase and Decrease buttons simultaneously for at least 3 seconds until the red light turns on Turn off the 120 VAC by Power ON OFF switch and turn back on The 101 and 991 error code should then be cleared
68. sformer heater if transformer fails 2 A failed transformer can cause electrical damage to other electrical components within the water heater Error codes when N A transformer fails 1 Visual inspection connection breakage of wires and or signs of electrical Diagnostic damage 2 Check voltages of the transformer Proper range of values shown below White Black 120 VAC less than 10 Color Number of wires Brown Brown 100 less than 1 0 Brown Brown Function To power computer board and heaters 100 VAC ES x 2 3 White Black From the 120 VAC power supply ON Nm L 1 2 azov azov 150nm J y 5 7 8 150nm 2 3 4 HF 5 7 8 32 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 17 Igniter Unit Part 711 Takagi Part EKN74 Checkpoint To ignite the gas air mixtures when the water heater is ready to burn gas on Function its burner surface The output voltage of the igniter is more than 14 kVDC 1 Unable to ignite during the ignition process 2 Makes attempts to ignite at all times 1 The wat
69. t exchanger 2 Check voltages and resistance proper range of values shown below Color Number of wires Blue Blue Less than 1 00 When temperatures exceed 194 F 90 C the reset button trips and switch goes to OFF mode ON mode lt 194 F 90 OFF mode to reset switch back to ON mode press the reset button Reset Button 90 nark Y 3 4 18 4mm 3 8 15m 28 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 13 Overheat cut off fuse Unit Part Takagi Part EK333 Checkpoint 2 overheat cutoff fuse contains solder with a melting point of 430 F 221 C Detects excessive temperatures within the water heater especially around Function the heat exchanger and combustion chamber Upon detection communication between the computer board and gas valves will sever shutting down the water heater instantly The 111 or 121 error code will display 1 Unable to detect the excessively high temperatures within the water Failure events Effects on the water 1 Flames from burner may penetrate a ruptured damaged heat exchanger heater if the overheat 2 Gas valves will not operate cutoff fuse fails Error codes when the overheat cutoff fuse fails 1 Visual inspection connection breakage of wires 2 Check voltages and resistance proper range of values show
70. te control 2 If the computer board works properly the 7 seg LED will light in a circular 0 pattern one segment at a time Displaying error code history 1 Briefly press the Error call button do not hold down the button 6 2 2 lf the T D2 IN or T D2 OS has had prior error codes the ZAS l l seg LED will displav the most recent error code first E Ar Pressing the button again will display the 274 most recent error code and so on Computer saves a maximum of 10 error codes If the T D2 IN T D2 OS has never had lt gt error codes the 7 seg LED will display a bar IN Ole AR LU MN e EN Clearing error code history memory 1 Press and hold the Error call button for at least 5 OU seconds Cy of 23456 2 The 7 seg LED will display C L and r in A i succession to signifv that the computer board 2 MR memory has been erased of all error codes 2 518 50 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 3 Clearing the 101 and 991 error code The 101 and 991 erro
71. tely 62 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 12 12 Adjusting manifold gas pressure The manifold gas pressure on the T D2 IN or T D2 OS can be adjusted by following the procedures Adjusting the manifold pressure can cause unexpected combustion conditions during N operation which can cause a health hazard damage the T D2 IN or T D2 OS and or shorten its lifespan Therefore changing the manifold pressure is not recommended WARNING unless there are very strong reasons to do so e g high elevation installations and with the consultation of the Technical Services Department Adjusting maximum manifold pressure 1 Ensure that T D2 IN or T D2 OS is not in operation 2 Remove the screw off the manifold port of the T D2 IN or T D2 OS Figure 1 3 Connect a manometer to the manifold port using a tube Figure 2 Ensure that this connection is secure enough to prevent gas leak 4 Run water through the T D2 IN T D2 OS to activate its operation If presence of a gas leak is detected immediately shut off the T D2 IN or T D2 OS and inspect the tube manifold connection otherwise proceed onto the next step 5 Press and hold down the MAX button on the computer board While holding down the MAX button press either the Increase or Decrease button to increase or decrease the manifold gas pressure respectively Figure 3 Refer to the manometer to verify that pressure has been set to
72. ter heater has been installed indoors 6 Check if there is any blockage in the intake air and or exhaust 7 Check if there is dust and lint in burner and heat exchanger when the water heater has been installed in laundry room 8 Check if there is grease and dirt in burner and fan motor when the water heater has been installed in restaurant 9 Check the manifold pressure in the water heater water heater Natural of Malfunction description Cancellation method Fluctuation Fault of gas solenoid valves SV amp SV3 during of hot water Change of the combustion stage temperature _Fault of flow adjustment valve Diagoss checkpoint Check whether the filter in cold water inlet is cleaned 2 Check whether the gas supply pressure is adequate 3 Check for cross connections between cold water lines and hot water lines 3 CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 Natural of Di Checkpoint lagnosis Fault 9 Fluctuation 4 Fault of PCB in the water heater 1 No voltage to gas solenoid valve SV Normal 78 to 100 VDC between COM blue amp 9 green during operation 2 No voltage to gas solenoid valve 5 3 Normal 78 to 100 VDC between COM blue amp 73 red during operation 5 Gas solenoid valve SV fault 1 Disconnected wiring to gas solenoid valve SV Normal 1 3 to 1 9 between COM blue 9 green 2 Disconnected wiring to gas solenoid valve SV3 Norm
73. the following conditions ON OFF Conditions Re circulation mode The BTU requirement is more than 18 600 BTU h Conditions that activate OR the pump 30 minutes have elapsed after previous operation 4 minutes after activation if the computer detects a BTU requirement of less than 14 800 BTU h the computer will stop the pump in 90 seconds Conditions that deactivate the pump The computer records the inlet temperature and the flow rate of the pump during the final minute of its previous operation when calculating the BTU requirement 58 CONFIDENTIAL T D2 IN T D2 OS Service Manual Ver 1 00 12 8 B Pump control ON OFF conditions BTU requirements A Calculating the ON OFF conditions of the pump Condition needed to turn the pump XGPM x500 gt 18 600 Condition needed to turn the pump OFF 4 minutes after activation if the computer detects a BTU requirement of less than 18 600 BTU h the computer will stop the pump 90 seconds Ta Tin XGPM x 500 14 800 Or Tm lat Where Tse Set temperature and Tin Inlet temperature B Calculation example Set temperature Tse 122 F Flow rate 2 5 GPM Condition needed to turn the pump ON 122 Tin x2 5 x500 gt 18 600 Tin lt 107 1 F Condition needed to turn the pump OFF 122 Tin x2 5 x500 lt 14 800 Tin gt 107 1 F C ON OFF table Set temperature Flow rate GPM eee 62 8 92 4 102 3 107 2 110
74. valve assembly For safety reasons these assemblies mark LP ss should be installed in the unit asa whole set 9 The gas manifold for the LP has the 46V mark and the gas manifold for the NA has the 59 mark on the manifold plate 6 7 8 175nm CONFIDENTIAL T D2 IN T D2 OS Service M anual Ver 1 00 10 3 Fan motor EKK25 T D2 IN Unit Part 103 Takagi Part Checkpoint EKK54 T D2 OS function function provide combustion air into the combustion chamber and to exhaust flue gas 1 Fan speed failure causing abnormal sounds with or without combustion during operation Failure events 2 Unexpected activation caused by the connectors of the fan motor getting wet 3 Disconnects from the bottom of the combustion chamber 1 The water heater does not function properly Effects on the water Ww 2 Failure to ignite or abnormal ignition heater if fan motor fails 3 Unstable combustion conditions Error codes when the fan 101 111 121 611 991 motor fails 1 Visual inspection connection breakage of wires or dust causing electrical Diagnostic shortage 2 Voltage check proper range of voltages shown below Red Blue 110 to 160 VDC Input

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