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T-K3 Instantaneous Water Heater Service Manual

1. Interm ittent mode This mode is the normal default mode Continuous mode This mode is for heating systems that require pumps to continuously run ON Dipswitch settings for the ON OFF III id conditions of the pump control OFF Pump connectors Intermittent mode Continuous mode ON OFF Conditions Default setting lt Dipswitch set to OFF gt lt Dipswitch set to ON gt The BTU requirement is more Conditions that an 16 000 se The BTU requirement is more than ira 11 900 BTU h BONA DE RD ai rite hata elapsed after previous operation A Non stop pump operation 4 minutes after activation if the computer detects a BTU Once the computer sends an ON Conditions that requirement of less than signal to the pump it will never deactivate the pump 18 600 BTU h the computer send a STOP signal The pump wil stop the pump in 90 wil continually run non stop as seconds long as there is pow er to the T K3 The computer records the inlet temperature and the flow rate of the pump during the final minute of its previous operation w hen calculating the BTU requirement can shorten its lifespan Therefore running on Continuous mode is not Running pumps continuously for long durations may damage the T K3 and N recommended unless there are strong reasons to doso CAUTION 52 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 10 Pump control ON OFF conditions BTU requirements for Intermittent mode A Calcu
2. lt Q o TG je e o 2 o A Mi 2 B o ration time during JO to 720 minutes After Error code history displays 2 most recert error code Error code history displays 3 most recent error code Clears memory in error code history Air Fuel ratio stage O to 15 nomal condition 6 Operation ti i current rotation N A 44 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 2 The error code button Verifving functionalitv of computer board Displaving error code historv and Clearing error code historv memorv The T K3 has as error code button on the computer board that provides three main functions The button is located next to the 7 seg LED please look at the picture to the right NS IS Error code button A Verifying functionality of com puter board 1 Check the pow er supply to the GFI If the red light turns on after pressing the test button on the GFI the GFI is receiving power After verifying power press the reset button to turn of the light 2 Briefly press the error code button do not hold down the button 3 If the computer board works properly the 7 seg LED shows the most recent error code in its error code history or a bar if there are no error codes saved to memory as shown in the picture to the right B Displaying error code history 1 Briefly press the error code button do not hold down the button 2 If the T K3 has had prior error codes the
3. Ilaec OH CF Outlet l Thermistor l as Air fuel ratio rod 1 1 LI PTE Ler Flame rod aes i IL EN Bypass valve TER 1 1 Po J PT ER Igniter rod Fan motor TI T E 3900 1 LI Igniter Flow adjustment valve w Flow sensor i Gas solenoid valve 3 Heater l j Main gas valve 3 i i dl 23 p Mixing AD AD Thermistor AH ZY ju ae H C Drain plug O O Gas proportional valve T L Gas solnoid valve 1 D Gas solenoid valve 2 Inlet Inlet drain Thermistor plug filter Transformer When a hot water tap is opened cold water enters the T K3 w ater heater The water flow sensor detects this w ater 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 NQOaPF WN gt Using thermistors to measure temperatures the computer modulates the gas and water valves to ensure proper output w ater temperatures 8 When the tap is closed the T K3 water heater shuts down CONFIDENTIAL T K3 Service Manual Ver 1 05 6 Wiring diagram A2 35 mm lal AC120V a TE FETS W White BL Blue R Red G Green former my BK Black Y Yellow DE ne P Purple O Orange d LB Light blue BR Brown Heater BK Heater BK
4. O RING P14 EPDM OS SP O RING P6 EPDM TK2 TRD20 TRJr TK1S OS SP TM1 TM199 TH1 O RING P4 EPDM TR2 TRD20 TRJr TK1S OS SP TM1 TM199 TH1 FASTENER 16A TK2 TRD20 TRJr TK1S OS SP TM1 TM199 TH1 FASTENER 14 22 FASTENER 16 25A FASTENER 4 11 COMPUTER BOARD TRANS FORMER TH1 OS SP GEI TKJr TK1S TH1 IGNITER TKJr TR1S OS SP TH1 FREEZE PROTECTION THERMOSTAT TRJr TK1S OS SP FUSE ASSEMBLY TKJr TK1S OS SP TH1 FUSE BOX TKJr TK1S OS SP COMPUTER BOARD COVER AC100V WIRE EH IG WIRE GAS VALVE WIRE FAN MOTOR CABLE RS VG WIRE WATER VALVES WIRE FLAME ROD WIRE THERMISTORS WIRE TRANS FORMER WIRE PROPORTIONAL GAS VALVE WIRE HIGH VOLTAGE IGNITER WIRE 69 15 Revisions Version Description of changes 1 00 1 01 1 02 1 03 1 04 1 05 Sample evaluation Revision of w rong information in the section 10 11 and 12 Revision of w rong information in all section Revised by PP Revised by PP Revised by the R amp D and Takagi Japan 70 CONFIDENTIAL T K3 Service Manual Ver 1 05 Date 10 19 07 10 28 07 11 28 07 1 14 08 2 20 08 3 4 08
5. To sum it up in a chart 25 minutes have Inlet thermistor Outlet thermistor Will automatic firing elapsed since prior temperature temperature be activated Above 37 F operation 37 F and below 43 F and below 61 CONFIDENTIAL T K3 Service Manual Ver 1 05 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 K3 Electrical pow er 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 62 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 17 Freeze protection for recirculation svstems If the T K3 pump control is used to control a recirculation pump w hen needed the computer w ill activate this pump to provide flow and prevent freezing throughout the recirculation system For instructions on connecting the recirculation pump to the pump control port on the T K3 computer board refer to Section 12 13 Relay selection for the pump control connection Q To use this feature in a multiple unit Easv link system the pump must be connected to the T K3 pump control port in the Master unit Refer to Section 12 13 for details lt While recirculation system freez
6. 14 A or more computer board The AFR rod is assembled vvith the flame rod ama Color Num ber of S q Detecting elements AFR and flame rods n Leads to computer board 18 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 7 Heatexchanger T K3 Part f AQ1 Takagi Part EKK1X checkpoint Functi Absorb heat from combustion and transfer it to water through the heat ie exchanger pipes 1 Clogged heat exchanger fins and or cracks on the heat exchanger walls Failure event 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 detect this event and immediately stop the T K3 from operating 3 Abnormal sounds during combustion Effects on the T K3 if the heat exchanger fails 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 Color Number of wires 19 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 8 Flow adjustment valve T K3 Part 402 Taka
7. 391 suppl Diagnosis cem nt 1 AFRrod fault Refer to section 10 6 Visual inspection connection breakage of wires and or soot buildup 36 CONFIDENTIAL T K3 Service Manual Ver 1 05 Error Codel Malfunction description Cancellation method FI fail Turn off the power or water ow sensor failure Isupply Diagnosis 1 Flow sensor fault 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 amp Error Code Malfunction description Cancellation method Fault of driving circuit for any of the gas solenoid valves MV SV4 SV5 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 after every operation Diag 1 PCB and or gas valve fault Refer to section 10 4 amp 10 15 Visual inspection of gas valves connection breakage of wires Normal DC787 100V between COM blue amp 3 light blue Normal DC7 8 100V between COM blue amp 9 green Normal DC78 100V between COM blue amp 53 orange Normal DC78 100V between COM blue 8 73 red Visual inspection of PCB connection breakage of wires and or burn marks on the computer board 2 Gas solenoid valve fault MV SV4 SV2 and or SV Malfunction description Cancellation method Fan motor fault usd the power or water D
8. 60Hz power supply 2 If the remote controller is used check whether the power button is turned on 3 Checkthat the filter on the cold water inlet is clean 4 Check whether the hot water fixture is sufficiently open to draw at least 0 5 GPM through the water heater 5 Checkthat the filter on the cold water inlet is clean 6 Check whether or not the unit is frozen 7 Checkifthere is enough gas in the tank for 32 CONFIDENTIAL T K3 Service Manual Ver 1 05 1 Check whether the flow rate enough to keep the T K3 enough to keep the T K3 running Check if there is a recirculation system installed and check also if the recirculation line has enough check valves Check that the filter on the cold water inlet is clean The hot water tums cold and stays cold Check that the fixtures are free from debris and obstructions The fan motor is still This is normal After operation has stopped the fan motor keeps its running from 5 to 50 sec in order to re ignite quickly as well as purge all the exhaust gas out of the flue Check if there is any blockage on the air inlet of the unit Check if there is sany dlocieage of the ela pipe Abno mal sounds come from the unit Malfunction description Cancellation method Fault of gas solenoid valves SV3 amp SV during stage changes Fault of flow adjustment valve Fluctuation M Aee temperature Check whether the filter in cold water inlet is cleaned u Check whe
9. K3 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 K3 to activate its operation If presence of a gas leak is detected immediately shut off the T K3 and inspect the tube manifold connection otherw ise 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 INC REASE or DEC REASE 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 6 After gas pressure has been set deactivate the T K3 remove the mano meter tube and replace the port screw 57 CONFIDENTIAL T K3 Service Manual Ver 1 05 Figure 1 Manifold port Figure 3 MAX button MIN button Increase button Decrease button T K3 computer board Tube To Manometer 58 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 15 Manuallv adjusting the fan motor speed While the FM dipswitch will automatically increase the fan speed by 6 the fan motor speed on the T K3 can also be manually adjusted In order to perform manual adjustments to the speed a TM RE10 or TM RE30 remote controller is required air for combustion w hich can cause excess CO emission from the exhaust chamber if the fan motor speed is set incorrectly
10. Therefore this procedure should never be WARNING performed unless Takagi USA has given consent and authorization i Manually adjusting the fan motor speed of the T K3 will change the amount of intake Adjusting maximum fan motor speed 1 While T K3 is in operation set dipsw itch No 2 to the ON position Figure 1 2 On the temperature remote controller display mode 3 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 MAX 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 speed has been set to desired value 4 After fan speed has been set set dipswitch No 2 back to the OFF position Adjusting minimum fan motor speed 1 While T K3 is in operation set dipsw itch No 2 to the ON position Figure 1 2 On the temperature remote controller display mode 3 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 speed has been set to desired value 4 After fan spee
11. continually check the temperatures of the inlet and outlet ther mistors the outlet thermistor is the one that checks the temperature of the water immediately leaving the heat exchanger not the water leaving the T K3 which is mixed with w ater fromthe bypass valve The automatic firing svstemw ill 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 39 F and T lt 50 F OR Tout S 37 F where Tj is the temperature of inlet thermistor and T is the temperature of the outlet ther mistor 60 CONFIDENTIAL T K3 Service Manual Ver 1 05 To sum it up in a chart 5 minutes have Inlet thermistor Outlet thermistor Will automatic firing elapsed since prior temperature temperature be activated operation pNo w Ary NO vs weestr aw Nv S Nes Any wes N5 Outdoor installation After 25 minutes have elapsed since the T K3 s previous firing operation the computer will continually check the temperatures of the inlet and outlet thermistors The automatic firing systemwill 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 lt 43 F OR Tout 3 F where Ti is the temperature of inlet thermistor and T is the temperature of the outlet ther mistor
12. from left to right or right to left e When more than 4 T K3s are connected in an Easy link system only the first 4 T K3s willw ork as a system The remaining T K3 s will not operate 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 K3 unit for 10 sec NOTE In a single unit installation the numbering system is disabled B How to reset and reconfigure the numbering of units Unit s can be reset and reassigned manually 1 Press and hold the Increase button on the computer board of all slave units for at least 5 seconds 2 The 7 seg LED on the computer board of all slave units will display O to signify that the computer memory has been erased of its previously assigned unit 3 Press and hold the Increase button again New unit will be assigned in order as you proceed through every unit Increase button T K3 Computer board 48 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 6 T K3 ON OFF conditions Overview The T K3 has two modes of ON OFF conditions Select either mode by changing Dipsw itch 3 on the upper bank of dipsw itches as shown in the picture to the right Intermittent mode This mode is the normal default mode Continuous mode This mode is for heating systems that deal w ith smaller te mperature differentials ON OFF Conditions Conditions needed to turn th
13. is designed to only work with a 100VAC power supply therefore the T K3 comes equipped with this transformer Failure event 1 There is no power coming from the transformer 2 The voltage from the power supply cannot be converted to 100VAC 1 The T K3 does not operate due to lack of power from transformer Effects on the TKS 2 A failed transformer can cause electrical damage to other electrical components if transformer fails s within the T K3 transformer 1 Visual inspection connection breakage of wires and or signs of electrical damage 2 Check voltages of the transformer Proper range of values shown below Color Number of White Black 120VAC less than 10 wires Brown Brown 100VAC less than 10 To power the computer board and heaters 100VAC 2 3 8 61mm From the 120 VAC power supply 12DV11B9V 5 7 8 150mm 28 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 17 GFI T K3 Part 703 Takagi Part EKN73 Checkpoint F Detects electrical leakage in the T K3 unction Stops providing power to the T K3 in the case of electrical leakage Fail 1 ON failure Always in the ON mode never trips allure event 2 OFF failure Always in the OFF mode always stays tripped Effect he T K3 1 ON failure GFI cannot detect electrical leakage within the T K3 cus Meque 2 OFF failure the T K3 does not receive any power from the GFI which THERE RS means the T K3 cannot operate Error codes wh
14. 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 Effects on the T K3 2 Excess carbon monoxide emissions if valves fails 3 Lack of water temperature control 4 No flames the valves fail 1 Visual inspection connection breakage of wires 2 Listen for clunk sounds from the gas valves opening right after fan motor initiates 3 Check voltages and resistance of coils proper range of values shown below Blue Red DC 78 100V 0 9 1 7K 2 Blue light blue DC 78 100V 0 9 1 3K Q Blue Orange DC78 100V 1 3 1 9K 2 Blue Green DC78 100V 1 3 1 9K 2 hite Red Proportional Valve DC 1 15V 20 400 7 8 i Color Number of wires 4 5 8 119mm Proportional Valve CONFIDENTIAL T K3 Service Manual Ver 1 05 10 5 Flame rod T K3 Part f 716 Takagi Part EKKOE Checkpoint mm Function To detect flames while unit is in operation 1 Unable to detect flames when flames actually do occur Paure aveni 2 Detecting a false flame when no flames actually occur Effects on the T K3 1 The T K3 stops operating The 111 and or 121 error code s will display if flame rod fails 2 The T K3 will not initiate the ignition process The 721 error code will display Error codes when the flame rod fails nn m 121 1 Visual inspection connection breakage of wires or soot buildup on rod 2 Chec
15. of values shown below Red Black DC 4 5 5V Input Color Number of pes White 85 Black DC 1 4V pulse 1 080 pulse min more than 18Hz The flow sensor is assembled with the flow adjustment valve Flow adjustment 2 5 8 67 5mm 84 4mm 3 3 8 1 7 8 47mm 21 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 10 Bvpass valve T K3 Part f Takagi Part EKKOU Checkpoint 1 Mixes hot water from the heat exchanger with cold water from the water inlet in order to modulate and control the T K3 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 Fail t 1 Water leakage from valve n 2 The valve cannot modulate or make open close positions 1 Water leakage from failed valve can damage other T K3 components 2 Temperature fluctuations in the hot water output 1 Visualinspection connection breakage of wires 2 Check voltages and resistance proper range of values shown below Red Number of IReg Black DC7 16V and 0 09 0 2kO 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 Diagnostic 84 4mm 3 3 8 e Bypass ji i 47mm WATER WATER OUT WATER OUT 22 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 11 Themmistors 406 Inlet EKK38 In
16. or less between blue amp blue Error code is i i A 7 Disconnected damaged hi limit switch Refer to section 10 12 ree talle attempts at Visual inspection connection breakage of wires ignition Normal 1 or less between blue 8 blue Error Codel Malfunction description Cancellation method Disconnected short circuited outlet Turn off the power or water 311 thermistor supply Diagnosis O g 1 Outlet thermistor fault Refer to section 10 11 Visual inspection connection breakage of wires and or debris on thermistor Check voltag e resistance between black amp black 12 Error Codel Malfunction description Cancellation method Turn off the power or water suppl p Diagnosis Checkpoint 1 Inlet thermistor fault Refer to section 10 11 Visual inspection connection breakage of wires and or debris on thermistor Check voltage resistance between black amp black 42 Refer to Section 8 for ge of values Error Code Malfunction description Cancellation method Disconnected short circuited mixing Turn off the power or water 331 thermistor suppl 321 Disconnected short circuited inlet thermisto 1 Mixing thermistor fault Refer to section 10 11 Visual inspection connection breakage of wires and or debris on thermistor Check voltag e resistance between black amp black 113 Malfunction description Cancellation method Disconnected AFR rod Turn off the power or water
17. severed shutting down the T K3 instantly The 111 or 121 error codes will display 1 Unable to detect excessively high water te mperatures if switch fails closed Failure event 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 T K3 if the water temperature from the heat exchanger exceeds 194 F 90 C Effects on the T K3 Note The mixing and outlet thermistors always act as backup hi limit detectors to detect if hi limit switch fails excessively high water temperatures in the heat exchanger 2 The T K3 is always shut down immediately after the ignition process and either the 111 or 121 error code will display 111 121 The T K3 doesn t have the 141 error code that was used in our previous models This error code is now replaced by the 111 and the 121 error codes Error codes when hi limit switch fails 1 Visual inspection connection breakage of wires Possibility also includes scale deposits inside the heat exchanger 2 Check voltages and resistance proper range of values shown below When temperatures exceed 194 F 90 C the reset button trips and switch goes to OFF mode ON mode lt 194 F 90 C OFF mode to reset switch back to ON mode press the reset button Reset Button 24 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 13 Overheat cutoff fuse T K3 Part so Takagi Pa
18. 7 seg LED will display the most recent error code first Pressing the button again will display the 2 1 most recent error code and so on Computer saves a maximum of 10 error codes If the T K3 has never had any error codes the 7 seg LED will display a bar C Clearing error code history memory 1 Press and hold the error code button for at least 5 seconds 2 The 7 seg LED will display C L and r in succession to signify that the computer board me mory has been erased of all error codes 45 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 3 Clearing the 991 error code The T K3 s 991 error code signifies imperfect abnormal combustion caused by insufficient intake air and or obstructions in the exhaust A If the 991 error code occurs please check the follow ing What is the T K3 s gas type liquid propane or natural gas How long has the T K3 been installed and been in use Where is the T K3 installed indoor outdoor attic etc What is the altitude elevation of the area of installation If installed indoors how long is the vent length If installed outdoors vv hat type of vent cap is used NO a fF WN gt Are there any obstructions in the intake air and or exhaust B How to clear the 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
19. CONFIDENTIAL T K3 Service Manual Ver 1 05 T T K3 Instantaneous Water Heater TAKAGI Service Manual m CINA GEM lt TAKAGI Industrial Co USA Inc 5 Whatney Irvine CA 92618 Toll Free 888 882 5244 USA Toll Free 877 877 4953 CANADA CONFIDENTIAL T K3 Service Manual Ver 1 05 Table of Contents 1 Specifications of the T K3 T K3 OS and T K3 SP sss 3 2 Exterior view ene 4 82 Interior VIEW tir tester ens hana x tat kat SRM ae Ced pns ia aa amat IN EEEE 5 4 List of main components in the interior view seren nn 6 a Schematic GION D TTE ERIT o o OL LS SET 7 6 Wiring CIC acs sib tipa s kac tueoo sese dad ab mai keta ti ie scan ASSI ana abet ata arti nat 8 7T Wiring diagram checkpoints for diagnosis eses HM 9 8 Resistance values of the temperature ther mistors seen 10 9 Operational flow chart nr e men nr meme rer eren 11 10 Component specifications rna n nr memes 12 11 Fault Analysis amp SpeciTICallOris enano tete cusses bene esas da a le na 32 12 Controls and SGUINGS xi ii iri 40 13 Components diaga MS i ie a varse hana onen eA E EEA EEE aan ai 65 DL ME cai e 68 15 RVISIONS 0 ccc cece cece ence cence eee ee e sese esent e e esie es eme i serre Eni 70 CONFIDENTIAL T K3 Service Manual Ver 1 05 1
20. Condition needed to turn the pump ON 122 Tn x 25 x 500 gt 11 900 Tin lt 112 5 F C ON table Set temperature Flow rate of pump GPM P 1 0 1 5 2 0 2 5 3 0 3 5 4 0 tota 1035 1051 1062 107 106 1 110 1 112 5 114 1 115 2 116 1 54 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 12 Multi unit svstem ON OFF conditions In Easv Link multi unit systems the amount of T K3 s called on to activate depends on the FLOW RATE and the OUTPUT SET T EMP ERAT URE 1 Condition required to activate an additional T K3 Flow rate required to activate additional T K3 Ax n Where n number of currently activated T K3 s and A is dependent on the output set temperature See table below im set te ios re Factor A L min 100 122 37 50 mmm 2 L 9 pz en 15 NONNENE les we ws 21 8 2 Condition required to reduce the number of activated T K3 s A In the case of reducing down from 2 T K3 s to 1 T K3 Flow rate A 1 7 B All other cases Flow rate A X n 2 3 Example Output set temperature 122 F in a 4 unit system and priority unit is No 1 To activate additional T K3 s To reduce number of activated T K3 s Flow rate l Flow rate Unit No GPM L min M L min No 4 OFF No 3 OFF No 2 OFF No 1 OFF 55 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 13 Relav selection for the pump control connection The maximum current capacity of T K3 s pump control connection is 1
21. Flow sensor OFF CLOSE the tap 611 blink Stop FM FM speed Above 1 000rpm2 20sec later STOP FM Peseudo flame 21 blink 111 blink 121 blink etry ignit MV OFF SV1 OFF GPV OFF SV1 SV2 SV3 OFF 5sec later Burning lamp ON Iginiter OFF 3sec later Proportional conjrol Sv2 Sv3 OFF SV2 SV3 ON ES blink AFR rod failure Loo blink Abnormal AFR 121 blink Melt OHCF Above 363r F 121 blink Flame rod failure EAV close 311 blink OuTH OPEN or SHORT 321 brink InTH OPEN or SHORT 20sec 331 blink MiTH OPEN or SHORT later len blink J Abnormal FM Speed FAV OPEN atetv devi XE work NO 11 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 Component specifications 1 Burners 4 2 Manifold 3 Fan motor 12 Hi limit switch 13 Overheat cutoff fuse 14 Heaters 15 Computer board 25 16 Transformer 18 Igniter 19 Freeze protection thermostat a CONFIDENTIAL T K3 Service Manual Ver 1 05 10 1 Burners T K3 Part 101 Takagi Part EKK1N Checkpoint N A There are 2 types of burners in the T K3 the gas rich burner stabilizes the flames within the combustion chamber and the air rich burner produces more heat in the combustion chamber The burners facilitate the air gas mixture necessary to produce the proper h
22. Freeze protection thermostat lL Tl Elect rod AFR rod BL et Br al DI Ground Flame rod SLAVE IN W BK SLAVE OUT W B J MASTER MAX button Mixing thermistor EF eK Out let thermi stor E s 9 Inlet h Controllerj l ye MIN button Increase button Decrease button Burning lamp Error call button 7 Seg LED CONFIDENTIAL T K3 Service Manual Ver 1 05 7 Wiring diagram check points for diagnosis Brown Brown A1 100V Power supplv AC 90 110V White Black A 120V Power supplv Black White AC 108 132V Light blue blue at COM DC 78 100V in operation 0 9 1 3kQ Green blue at COM DC 78 100V in operation 1 3 1 9kQ Orange blue at COM DC 78 100V in operation 1 3 1 9kQ Gas valves Red blue at COM DC 78 100V in operation 0 9 1 7kQ C Proportional Valve VVhite red at COM Hi li mit switch Blue Blue Less than DC 1V and less than 1 3 2 Overheat cutoff fuse Blue Blue Less than DC 1V and less than 1 3 2 Black White DC 15V during Easy Link operation Black White Easy link connectors Mixing themistor Black Black Outlet thermistor Black Black See table on p 10 Inlet themistor Black Black Remote controller O DC 11 25V Red Blue DC 110 160V Yellow Blue DC 13 17V Orange Blue DC 2 6 5V White Blue H1 Gas proportional valve White red DC 1 10V and 30 50 Q Red Black DC 4 5 5V White Black DC 1 4V 1080pulse mi
23. LD FAN MOTOR GAS VAL VE ASSEMBLY ELAME ROD IGNITER ROD GAS INLET BURNER PLATE GAS INLET RING BURNER WINDOW ROD HOLDER GASRET ROD HOLDER BURNER HOLDER GASRET PRESSURE PORT URETHAN TUBE MANIFOLD GASKET GFI PLATE IGNITER PLATE WIRE CLAMP 60 SCREW M4X 10 COATING SCREVV M4X10 SCREVV M4X 12 HEX HEAD SCREW M4X12 HEX HEAD SCREW M4X8 SCREW M4X 10 SCREW M3X8 SCREW M3X 10 SP SP SP TKJr TK1S OS SP TH1 OS SP OS SP OS SP OS SP OS SP SP SP OS SP TR2 TKD20 TRJr TK1S OS SP TM1 TM199 TH1 TK2 TKD20 TKJr TK1S OS SP TM1 TM199 T H1 TK2 TKD20 TKJr TK1S OS SP TM1 TM199 T H1 OS SP TR2 TRD20 SP TH1 TR2 TRD20 OS SP TH1 TK2 TRD20 OS SP TH1 SP TK2 TKJr TK1S OS SP TM1 TM199 HEAT EXCHANGER ASSEMBLV FLOW ADJUSTMENT W FLOW SENSOR BYPASS VALVE WATER INLET WATER OUTLET VALVE 68 CONFIDENTIAL T K3 Service Manual Ver 1 05 Description Common parts forother units INLET THERMISOR OUTLET THERMISTOR MIXING THERMISTOR HI LIMIT SWITCH TKJr TR1S OS SP TH1 SILICON RING T K1S T K3 T K3 S P T H1 OVER HEAT CUT OFF FUSE OS SP HEATER OS SP PIPE HEATER FIXING PLATE FUSE FIXING PLATE 18 INLET DRAIN PLUG INLET WATER FILTER INLET HEATER OUTLET DRAIN PLUG SCREW M4X6 SCREW M3X6 TK2 TKD20 TKJr TK1S OS SP TM1 TM199 TH1 O RING P16 EPDM TK2 TKD20 TKJr TK1S OS SP TM1 TM199 TH1 O RING P15 EPDM TRJr TK1S OS SP TH1
24. Specifications of the T K3 T K3 OS and T K3 SP Dimensions H20 5 xW13 8 x D8 5 H20 5 xW13 8 x D8 5 H20 5 xVV13 8 x D8 5 199 000 190 000 11 000 Combustion System Installation mason DUigoor Outdoor Indoor amp Outdoor amp Direct vent PWM turbo fan PWMfan PWM turbo fan Natural 2 5 W C Natural 2 8 W C Natural 2 4 WC LP 0 7 WC LP 0 8 WC LP 0 8 WC Natural 0 4 WC Natural 0 4 WC Natural 0 4 WC Flow rate 0 5 GPM to 7 0 GPM Available set 99 F 185 F 99 F 167 F default 122 F Default 122 F 104 F 113 F 122 F 131 F 140 F 158 F 113 F 122 F 140 F 167 F 176 F 185 F Pow er vent Combustion Temperature dipsw itch settings G 5 c fe a D z Bypass valve Ther misters 3 Nene 2 thermisters In Out In Out Mixing Remote controller TM RE10 model TM RE30 PCB model K3 T K3 OS SP Burning LED amp 7 SEG LED Pow er supply GFI Including surge control absorber TK REO2 Indicators Burning LED Operation Surge absorber amp Pow er switch Freeze protection cera s oda and Ceramic heaters Auto firing system Self combustion Air Fuel Ratio Detection System improvement Features CONFIDENTIAL T K3 Service Manual Ver 1 05 2 Exterior view Front view 13 3 4 0350mm Side view 4 1 2 114 2mm 1 3 4 45mm 1 3 4 45mm DA 6101 6mm 1 5 8 42 5mm 19 3 8 492 7mm
25. ae LD eos a 3 1 4 84mm COLD 1 3 8 36mm 120V 6 1 2 164 4mm HOT 5 1 4 132 9mm 4 7 8 124 3mm GAS 9 1 2 241 3mm Top view Bottom view 5 1 4 132 9mm 4 7 8 124 3mm 3 5 8 93 3mm 6 1 2 164 4mm 1 1 2 37 8mm CONFIDENTIAL T K3 Service Manual Ver 1 05 3 Interior view huh l ey Eei E ka f LI t a ila ta Wi E VR f ay A Wa REL ii IN Lr b 1 PI e O 69 9 4 List of main components in the interior view T K Takagi t No Description nA common par Part Part For other units 1 Case assembly 001 EKK1D 2 Combustion chamber 102 EKK1Y Gas valve with Proportional valve 4 Computer board 701 EKK1L i tt 5 Igniter 704 EKN74 TKur TK1S TH1 OS SP CONFIDENTIAL T K3 Service Manual Ver 1 05 4 List of main components in the internal view cont d Part Part with other models Do _Winxng thermistor 4e em Pio mememe f xe eee s owes xw Er 1 e Overheatcutorfuse fm Ecos wu mese me o ems o ek YC z Pow adustnentveve o enor 24 Manifold 03 EKKITINA EKK1S LP 25 bypassvene 0s mou CONFIDENTIAL T K3 Service Manual Ver 1 05 5 Schematic diagram Hi limit SW
26. amp Before using any relay with the pump control please check the specifications of that particular relav to ensure that the current value through the coil w ill not exceed 1 amp Coil Data 25 C For example i Nominal Power Maximum Power KRP AC 2VA Enclosed Models AVA To the right there is a sample of relay mapa Doc 12w EndosedModels 3W Enclosed Models 3W ifi i i KA AC 2VA Open Models 4VA specifications from an arbitrary brochure mW ma ee You can select either the 120VAC or 240VAC buty Cycle Continuous Initial Insulation Resistance KAP KRPA 1000 Megohms min relay because their current values are less KA 100 Megohms min than 1A 1 000mA Coil Data 25 C Nominal DC Resistance Q Nominal Coil Voltage 10 Bethe Current mAL 6 32 i 188 12 120 ee SOO eee DC 24 472 51 Coils 48 1800 26 6 110 10 000 115 220 Use 110V relay with 10 000 Q 5W Resistor in series 6 6 335 168 Through this circuit the maximum current capacity is 1A 7 Power Supply i er Typicall z ell ull ce for Relays yp y S Vot re e1 Power Supply for Pump 120VAC 8 A ol lotto o lt AC120V SEL molt els AC220V etc era Thermal AC120V Relay AC220V etc Relay 56 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 14 Adjusting manifold gas pressure The manifold gas pressure on the T K3 can be adjus
27. ct the mode H and the information to which the mode correlates to w ill display on the TM RE30 Fig 2 When the ON OFF button is pressed or 5 minutes have elapsed w ithout pressing any buttons the display w ill return to normal CONFIDENTIAL T K3 Service Manual Ver 1 05 LU HOT TIME Button COLD Button Button INFO BUZZER ON OFF Button Button Button 42 CONFIDENTIAL T K3 Service Manual Ver 1 05 lt For multiple T K3 s in an Easy Link multi unit system gt 1 Press and hold the HOT and C OLD buttons simultaneously for at least 5 seconds to enter Diagnostics Mode 2 0 will be displayed on the TM RE30 See Fig 1 3 Scroll to the desired T K3 unit in the easy link system by pressing the HOT or the COL D buttons to scroll up or down Fig 2 shows that unit 2 is being selecting NOTE The definition of the unit s 0 will yield information about the Easy link system as a whole and numbers 1 2 3 amp 4 will yield information about each of the individual T K3 s installed in the Easy link system In an Easy link system of T K3 s a maximum of 4 T K3 s can be linked together 4 Press the INFO button to select the desired unit 5 When the desired unit is 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
28. d has been set set dipswitch No 2 back to the OFF position Figure 2 Figure 1 MAX button MIN button Increase button Decrease button Dipsw itch settings T K3 computer board 59 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 16 Freeze protection svstem There are two features to the T K3 s freeze protection svstem the automatic firing svstem and the ceramic heating blocks The automatic firing system allows the T K3 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 drum The three heating blocks focus on protecting the inlet and outlet piping inside the T K3 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 K3 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 Gas and electrical pow er are required for this feature to operate Indoor direct vent installation After 5 minutes have elapsed since the T K3 s previous firing operation the computer will
29. e T K3 ON Conditions needed to turn the T K3 OFF Intermittent mode Default setting Dipswitch set to OFF The BTU require ment is more than 14 880 BTU h AND The water flow rate is more than 0 52 GPM The BTU requirement is less than 11 900 BTU h OR Inlet temperature is higher than the set temperature OR Outlet temperature 194 F is over OR The water flow rate is less than 0 4 GPM 49 OFF Continuous mode lt Dipswitch set to ON gt The BTU requirement is more than 11 900 BTU h AND The water flow rate is more than 0 52 GPM The BTU requirement is less than 7 440 BTU h OR Inlet temperature is higher than the set temperature OR Outlet temperature 194 F is over OR The water flow rate is less than 0 4 GPM CONFIDENTIAL T K3 Service Manual Ver 1 05 12 7 T K3 ON OFF conditions BTU requirements for Intermittent mode A Calculating the T K3 s ON OFF conditions Condition needed to turn the T K3 ON Tset Tin GPM x 500 gt 14 880 Condition needed to turn the T K3 OFF Tset Tin GPM x 500 lt 11 900 or Tin Tset Where T 4 Output 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 K3 ON 122 Ti x 2 5 x 500 gt 14 880 Tin lt 110 1 F Condition needed to turn the T K3 OFF 122 Ti x 2 5 x 500 lt 11 900 Tin gt 112 5 F The outl
30. e protection is in operation gt While this freeze protection is operating the T K3 computer board w ill not display anything on its 7 seg LED In addition the TM RE10 and TM RE30 remote controllers will also not display anything on its screen this is true whether the T K3 is in a single unit installation or a multi unit Easy link installation A Activation conditions all 3 conditions must occur 1 The T K3 is in non operation no call for hot w ater 2 Dipsw itch No 6 the upper bank on the T K3 computer board is set to the ON position 3 The T K3 computer of the master unit detects water temperature 50 F 10 C or below the computer will activate the pump every two minutes to properly measure w ater temperatures throughout the recirculation line B Deactivation condition After pump has been activated for freeze protection the pump is set to run for at least 1 hour After 1 hour has elapsed the T K3 computer of the master unit will actively measure water temperature Pump will deactivate if temperatures remain above 50 F 10 C continuously for 10 minutes 63 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 18 Draining the T K3 and cleaning the inlet water filter Close the manual gas shut off valve iy A Turn off power to the T K3 and then turn on again Ba Ss Wait 30 seconds for water valves to completely M open Then turn off power to the T K3 yet LL again Close the water shu
31. eat during the combustion reaction 1 Unable to initialize sustain combustion Failure events 2 Dust or soot deposit on the burner surface 3 Cracks onthe burners 4 Gas leakage from burners Effects on the T K3 1 An unexpected combustion ifb fail 2 Unstable flame conditions and or flame loss OUS ra des 3 Ignition failure Error codes when the burners fail Di ti Visual inspection excessive dust deposit on the burner surface and or unstable ete flame conditions during operation Color Number of N A wires 3 8 11 0mm 13 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 2 Gas manifold T K3 Part f 103 Takagi Part EKK1F Checkpoint 1 The manifold distributes gas from the gas valves to the burners The manifold has two types of the nozzles one type for gas rich burners 16 nozzles and the Function 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 Failure events 2 s l 13 Ignition failure 4 Imperfect combustion 1 The burners cannot receive proper gas flow from the manifold which can cause Effects on the T K3 jjpoor combustion in the combustion chamber In this case the AFR rod will detect ifthe manifold fails an improper flame condition and computer will take safety measures 2 Gas leakage from the manifold omi the manifold fails 1 Visual inspecti
32. en 1 Visual inspection connection breakage of wires and or some signs of electrical damage on the GFI 2 Check the power supply to the GFI If the red LED on the GFI lights up after pressing the test button the GFI is receiving power After verifying the power supply verify that 100VAC is entering and leaving the GFI wires To the computer PRISE li nm Reset button 29 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 18 Igniter T K3 Part f Takagi Part EKN74 Checkpoint B2 O To ignite the gas air mixtures when the T K3 is ready to burn gas on its burner Function surface The output voltage of the igniter is more than 14kV 1 Unable to ignite during the ignition process 2 Makes attempts to ignite atall times 1 The T K3 cannot ignite during the ignition process and the 111 or 121 error Effects on the T K3 codes will display ifthe igniter fails 2 No effects on the T K3 however the durability of the igniter wears down Error codes when Igniter fails 1 Visual inspection connection breakage of wires and or an observed weak spark 2 Check voltages proper range of values shown below xes Number of Purple 7 Purple 7 90 VAC 110 VAC Failure event ACQ0 to 110V mes T CN MA High voltage igniter cable igni te cable 30 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 19 Freeze protection thermostat T K3 Part 705 Takagi Part EKJ59 Checkpoint B1 Tem
33. et temperature at that moment will be 120 F C ON OFF table 1 0 A f F 1 5 2 0 2 5 3 0 3 5 4 0 i22 ON FF O 50 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 8 T K3 ON OFF conditions BTU requirements for Continuous mode A Calculating the T K3 s ON OFF conditions Condition needed to turn the T K3 ON Tset Tin GPM x 500 gt 11 900 Condition needed to turn the T K3 OFF Tset Tin GPM x 500 lt 7 440 or Tin Tse Where T 4 Output 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 K3 ON 122 Tin x 2 5 x 500 11 900 Tia lt 112 5 F Condition needed to turn the T K3 OFF 122 Tin x 2 5 x 500 lt 7 440 Tin gt 116 0 F The outlet temperature at that moment will be 120 F C ON OFF table set temperature Flow rate GPM F 1 0 il 5 2 0 2 5 3 0 3 5 4 0 a eee D e A c E l eee ee eee AE S EA I e a ie eee RN EIE on N FF N FF N FF N FF N FF N FF O 113 O O 122 O O 131 O O 140 O O 158 O O 167 O 185 51 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 9 Pump control ON OFF conditions Overview Dipsw itch 3 on the upper bank of dipswitches shown in the picture to the right also sets the mode for the pump control ONOFF conditions Again there are two modes of ONOFF conditions for the pump control
34. gi Part EKKOT Checkpoint J1 Controls water flow to properly control the output hot water temperaturet Failure event 1 Water leakage from valve 2 The valve cannot modulate or make open close positions Effects on the T K3 l 1 Water leakage from failed valve can damage other T K3 components ifflow adjustment 2 Temperature fluctuations in the hot water output 3 Within a multi unit Easv Link system the 651 error code can occur 1 Visual inspection connection breakage of wires motor drive locked due to scale buildup and or water leakage 2 Check voltages and resistance proper range of values shown below The flow adjustment valve is assembled with the flow sensor Flow adjustment f Flow sensor OUT No 3 EI F No 2 No 1 Bl ack Red 84 Amm Flow adjustment valve 3 3 8 adjustment 1 7 8 47mm valve 20 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 9 Flow sensor T K3 Part f 402 Takagi Part EKKOT Checkpoint Function Detects and measures water flow rate using a spinning impeller and magnetic pick Unable to detect or measure any water flow rate Elles me TS Ignition sequence does not start T K3 will not initiate any operation ifflow sensor fails Error codes when S z f the flow sensor fails 441 only within multi unit Easy Link systems 1 Visual inspection connection breakage of wires and or debris on impeller ud 2 Check voltages proper range
35. he INC and DEC buttons on the computer board simultaneously jfor more than 3 sec Diagnosis Jcheckpointi Check for blockage on the air inlet of the T K3 Check for blockage of the exhaust run Check for proper manifold pressure in the T K3 Consider altitude elevation of region of where the T K3 installed 39 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 Controls and settings 12 1 A Diagnosing the T K3 using the TM RE1O LL nn nn 41 12 1 B Diagnosing the T K3 using the TM RE3O L nn 42 12 2 The error code button Verifing functionalitv of computer board Displaving error code history and Clearing error code history MEMOrv L en nee 45 12 3 Clearing the 991 error CODE iino ere bes l 46 12 4 Dipsw diu o T 47 12 5 Assigning unit numbers in the Easy link svstem cece eerren 48 12 6 T K3 ON OFF conditions Overview L nn ee ee eee ea teeta eeeeeeaeneeaeees 49 12 7 T K3 ON OFF conditions BTU requirements for Intermittent mode 50 12 8 T K3 ON OFF conditions BTU requirements for Continuous mode 51 12 9 Pump control ON OFF conditions Overview L e ee eee teens eaeeeeees 52 12 10 Pump control ONOFF conditions BTU requirements for Intermittent mode 53 12 11 Pump control ON OFF conditions BTU requirements for Continuous mode 54 12 12 Multi unit system ON OFF conditions nr n
36. iagnosis 1 PCB and fan motor fault Refer to section 10 3 amp 10 15 Visual inspection of fan motor connection breakage of wires or dust buildup causing electrical shortage Normal DC 110 160V between red amp blue Normal DC 137 17V between yellow amp blue Normal DC 2 0 6 5V between orange amp blue Turn off the power supply Verify fan motor speed of the T K3 using the diagnostics mode of the TM RE10 temperature remote controller See the 12 1 How to diagnose the T K3 using the TM RE10 Visual inspection of PCB connection breakage of wires and or burn marks on the computer board 37 CONFIDENTIAL T K3 Service Manual Ver 1 05 Error Codel Malfunction description Cancellation method Turn off the power or water Flow adjustment valve fault supply Checkpoint 1 PCB and flow adjustment valve fault Refer to section 10 8 amp 10 15 ISUdl IMSPECUOMN OI HOW AQJUSU IENL Valve connecuon Dre aKkag of yi res motor drive locked due to scale buildup and or water Normal DC 7 16V between black red Visual inspection P CB connection breakage of wires and or burn marks on the computer board ErorCode Malfunction description Cancellation method 1 PCB fault D Fault of preparation for the outlet thermistor operation Fault of driving circuit for Gas Proportional Valve V Go SSDs Checkpoint 1 Checkthe PCB Refer to section 10 15 Visual inspection con
37. ilure sibi 2 Check the igniter Refer to section 10 18 Error code is Visual inspection connection breakage of wires and or shown after observed weak spark three failed D Cracks soot on igniter rod attempts at 2 Improper gap between bumer amp igniter rod ignition Normal gap 0 16 PCB fault Normal AC 90 110V at 7 purple purple Igniter fault Ea eT eT AN URN 3 PCB fault No voltage to main gas solenoid valve MV Normal DC78 100V between COM blue amp 3 light blue No voltage to gas solenoid valve SV1 Normal DC787 100V between COM blue amp 9 green 3 No voltage to gas proportional valve VGo Normal DC1 15V between white amp red 4 Gas solenoid valve fault CD Main gas solenoid valve MV fault Normal 0 97 1 3k between COM blue amp 3 light blue Gas solenoid valve SV1 fault Normal 1 37 1 9k between COM blue amp 9 green Gas proportional valve VGo fault Normal DC1 15V between white amp red 5 Disconnected damaged O H C F Refer to section 10 13 Visual inspection connection breaka ge of wires Normal 1 or less between blue 8 blue M AN CONFIDENTIAL T K3 Service Manual JOS 1 05 Error Code Diagnosis Segen 6 Disconnected damaged hi limit switch Refer to section 10 12 111 Visual inspection connection breakage of wires Normal 1 9 or less between blue amp blue Eroreddeds 7 Inspect flame rod showm an er D Check f
38. k amperes proper range of values shown below Orange 17 Green 18 during combustion 40KHz 60K Hz Color Number of Wars Orange 17 Flame rod between the flame rod and the during combustion 144 A or more computer board The flame rod is assembled with the AFR rod E Detecting elements flame and AFR E E o co ape eu ma y A vel ipm a Leads to computer board 3 1 2 1 3 8 17 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 6 AFR rod T K3 Part 716 Takagi Part EKKOE Checkpoint MS EE Checks flame conditions during combustion Functions When AFR rod detects unexpected flame conditions the T K3 s computer makes adjustments in the fan motor speed to compensate Fail t 1 Unable to detect flames when flames actually do occur arue Even 2 Detecting a false flame when no flames actually occur 1 The T K3 stops operating The 111 and or 121 error code s will display Effects on the T K3 2 The T K3 will not initiate the ignition process The 721 error code will display ifthe AFR rod fails 3 The fan motor speed cannot be modulated properly under abnormal flame conditions which can result in excessive CO emission Error codes when 1 Visual inspection connection braking of wires soot on it 2 Check voltages proper range of values are shown below Yellow 8 Green 18 during operation 40KHz 60 KHz Yellow 8 AFR rod a between the AFR rod and the during operation
39. lating the pum p s ON OFF condition Condition needed to turn the pump ON Tset Tin GPM x 500 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 w ill stop the pump in 90 seconds Tset Tn x GPM x 500 lt 18 600 oF Tin Tset Where Tet Output set temperature and Tin Inlet temperature B Calculation example Set temperature T e 122 F Flow rate 2 5 GPM Condition needed to turn the pump ON 122 Tin x 2 5 x 500 gt 18 600 Tin lt 107 1 F Condition needed to turn the pump OFF 122 Tin x 2 5 x 500 lt 18 600 Tin gt 107 1 F C ON OFF table ON values are the same as OFF values Set te mperature Flow rate of pump GPM 4 0 F 1 0 1 5 2 0 2 5 3 0 3 5 034 1071 wes ma nar 53 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 11 Pump control ON OFF conditions BTU requirements for Continuous mode Non stop pump operation A Calculating the pum p s ON OFF condition Condition needed to turn the pump ON Tset Tin x GPM x 500 gt 11 900 There are no conditions w hich turn the pump OFF A Non stop pump operation Once the computer sends an ON signal to the pump it will never send a STOP signal The pump w ill continually run non stop as long as there is pow er to the T K3 B Calculation example Set temperature Tse 122 F Flow rate 2 5 GPM
40. let E1 Mixing 407 Outlet Takagi Part EKK2T Outlet JC hechpoint E2 Outlet 408 Mixing EKK1A Mixing Measure cold hot water temperatures in the T K3 Failure event Unable to properly measure water temperatures within the T K3 Effects on the T K3 jif the thermistors fail open or short error code appears before starting operation If if thermistor fails resistance values are just off T K3 will have temperature fluctuations in hot water Error codes when thermistors fails 311 Outlet 321 Inlet 331 Mixing 1 Visual inspection connection breakage of wires and or debris on thermistor 2 Check voltages and resistance proper range of values shown below Inlet Black 42 Black 68 F 20 C 9 0 13KQ Color Number of 122 F 50 C 3 3 4 4KQ wires Outlet Black 12 Black 176 F 80 C 1 4 1 8KO Mixing Black 113 Black see table below for more resistance values nmm i let Inlet thermistor Blue EL Outlet thermistor Insulating Mixing thermistor Resistance values of thermistors as a function of Resisitance kQ 100 120 140 160 180 Temperature F 23 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 12 Hi limit switch T K3 Part Takagi Part EKN34 Checkpoint Basedon bi metal thermal expansion Detects excessively high water temperature more than 194 F or 90 C in pipes of the Function heat exchanger After detection communication between the computer board and gas valves are
41. mode 6 is being selected When selecting information please refer to the table on the next page for the proper mode 6 Press the INFO button to select the mode and information to which the mode correlates tow ill display on the TM RE30 Fig 4 7 When the ON OFF button is pressed or 5 minutes have elapsed w ithout pressing any buttons the display w ill return to normal 43 1 CONFIDENTIAL T K3 Service Manual Ver 1 05 Description of mode numbers in Diagnostics Mode Whole multi unit system irf ormation 0 Individual T K3 unit information 1 to 4 Total system flow rate 0 999 x 0 1 GPM Total operation time 0 to 9999 hours ON CFF cycles 0 to 9999 x 100 cycles JON OFF cycles 0 to 9999 x 100 cycles Quantity df connected 12 4 units Fan mdor speed 0 to 9999 rpm 1 4 unit f Inlet temperature 32 to 210 F Ov er 210 F E5 under 32F E0 T R3 s over 210 F E5 under 32F E0 Output set temperature 99 to 185 F 32 to 210 F over 210 F E5 under 327 E0 Air Fuel ratio rod 0 to 999 x0 1 A 720 the next rdation current occurs ON OFF cycles during 0 to 100 cycles After Flow rate 0 to 999 x 0 1 GPM 100 the next rdation occurs By passvalve position JO to 999 fully closed position 0 Ratio of hat water and JO to 999 x 0 1 cold water Error code history displays most recent error code H l o D o E 4 8 lt 2 3 9 c Q
42. n Fan motor Flow sensor Air fuel ratio flame rod Yellow AFR rod More than 1 4 A during burning Flame rod Orange Flame rod More than 1 4 A during burning J1 Flow adjustment valve Red Black DC 7 16V and 0 09 0 2k2 J2 Bypass valve Red Black DC 7 16V and 0 09 0 2kG R Pump connector port VVhite Black Less than 1 3 Q CONFIDENTIAL T K3 Service Manual Ver 1 05 8 Resistance values of the temperature thermistors Resistance values at different temperatures Temperature F vs Resistance kQ Resisitance RO 120 Temperature F Temperature C vs Resistance kQ Resisitance kQ 50 Temperature C 10 CONFIDENTIAL T K3 Service Manual Ver 1 05 9 Operational flow chart Power supply O Opeartion SW ON OPEN FAV BV FAV Flow Adjustment Valve B V Bypass Valve F M i Fan Motor 7 OHCF Over Heat Cut off Fuse OPES TON OEE M V Main gas Valve SV1 Solenoid Valve 1 AQRMA SV2 Solenoid Valve 2 SV3 Solenoid Valve 3 GPV Gas Proportional Valve InIH failure 321 s B i Bi 311 blink InTH Inlet thermistor OuIH failure 331 blink OuTH Outlet thermistor MiTH Mixing thermistor MiIH failure 701 blink 511 blink i OPEN the tap low Senso E Above 0 5GPMZ PCB Print Circuit board Computer board AFR Air Fuel Ratio POB TaTTure SV circuit failure FM speed Below 1 000rpm
43. nds to enter Diagnostics Mode 2 Number 0 w ill be displayed Fig 1 3 Scroll to the desired T K3 unit f either 1 2 3 or 4 by pressing the HOT or COLD buttons to scroll up or down 0 will yield information on the whole multi unit system Fig 2 4 Once desired is displayed press the w hite button located under the Buzzer Stop button to select the either a particular T K3 unit or the whole multi unit system The number 1 will then display right next to that selected Fig 3 5 Scroll through the mode ff s by pressing the HOT or COLD buttons Fig 4 6 Once desired mode is displayed press the white button located under the Buzzer Stop button to select the mode The information for that mode w ill be displayed Fig 5 T If 5 minutes have elapsed without pressing any buttons the display will return to normal Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 For example this sequence will display the flow rate information of the second T K3 unit 41 12 1 B Diagnosing the T K3 using the TM RE30 lt For a single T K3 gt 1 Press the HOT button and the COLD button simultaneously for at least 5 seconds to enter Diagnostic mode Scroll up or down to the needed information mode of the T K3 by pressing the HOT or COLD buttons Fig 1 shows mode 5 being selected When selecting information please refer to the table on p 44 for the proper mode H Press the INFO button to sele
44. nection breakage of wires and or burn marks on the computer board Error Code Malfunction description Cancellation method False flame detection Turn off the power or water 721 suppl Diagnosis Checkpoint 1 False flame detection 5 sec Flame rod insulated resistance fault Turn off the power or water supply Malfunction description Cancellation method Restoring proper cable 741 connections between the T K3 and the Remote controller TM RE10 or TM RE30 When the computer detects proper connections between the the T K3 and the remote controller 741 error code will cease to display P Diagnosis Checkpoint 1 Temperature remote controller TM RE10 TM RE30 or PCB fault 2 Check for signs of power surges Miscommunication between T K3 and temperature remote controller 38 CONFIDENTIAL T K3 Service Manual Ver 1 05 Error Code Malfunction description Cancellation method Restoring proper cable connections among all the T K3s Miscommunication between Master and When the computer detects Slave units for Easy Link systems proper connections among all the T K3s 761 error code will cease to display 1 Diagnosis Checkpoint Inspect cable connections between Master and Slave units um 2 Checkforsigns of power surges Malfunction description Cancellation method Abnormal buming Turn off the power or water Refer to section 12 3 suppl If not possible press and hold t
45. nn tn 55 12 13 Relay selection for the pump control connection 56 12 14 Adjusting manifold gas pressure na na a n na 57 12 15 Manually adjusting the fan motor speed nn nn nn 59 12 16 Freeze protection SYStOM i ii sineniiizi ba iezinezikkika twe ha bkei deb bid dieel BkB na HA NEA RE i dada 60 12 17 Freeze protection for recirculation Svstems nn eee 63 12 18 Draining the T K3 and cleaning the inlet w aterfilter 64 40 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 1 A Diagnosing the T K3 using the TM RE10 lt For a single T K3 gt 1 Press and hold the HOT and COLD buttons simultaneously for at least 5 seconds to enter Diagnostics Mode 2 Number 0 w ill be displayed Fig 1 3 Scroll through the mode s by pressing the HOT or Dis play Hot COLD buttons to scroll up or down Fig 2 4 Once desired mode is displayed press the w hite button located under the Buzzer Stop button to select the mode HEATER ON The information for that mode w ill be displayed Fig 3 5 If 5 minutes have elapsed w ithout pressing any buttons 5 the display w ill return to normal Zo o ES m Fig 1 Fig 2 Fig 3 For example mode 7 will display the value of the electrical current of the AFR rod Cold For multiple T K3 s in an Easy Link multi unit s ystem 1 Press and hold the HOT and COLD buttons simultaneously for at least 5 seco
46. oller even when remote is turned on Ittakes long time to get hot water at the fixtures the wiring diagram for checkpoint positions to T K3 when checking for continuitv disconnections resistance value 1 Checkthe power supplv Check the power supply from the GFI to the PCB Refer to section 12 2 Check the power supply line to the T K3 2 Fault of GFI Normal AC100V between white black Normal AC100V between brown brown 3 Fault of transformer D Disconnection breakage of wires Normal AC120V between white black Normal AC100V between brown brown 5 Fault of PCB D No voltage at remote control terminal Normal 11VDC 25VDC between white black 6 Disconnection short circuit grounding of remote wires Normal 11VDC 25VDC between white black 7 Fault of PCB of remote control D Checkfornomalvoltageatterminal 0 1 The time it takes to deliver hot water from the T K3 to your fixtures depend on the length of piping between them The longer the distance and or the bigger the pipes the longer it will take to get hot water The water is not hot enough The water is too hot 1 Check cross plumbing 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 1 Check whether the temperature setting is too high The hot water is not available when a fixture is opened 1 Make sure the unit gets a 120V
47. on Excessive dust deposit around the nozzles or cracks on the Diagnostic manifold 2 Check voltages and resistance pro ge of values shown below ss MD Blue Red DC 78 100V 0 9 1 7kQ 14 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 3 Fan motor T K3 Part Takagi Part EKK25 Checkpoint Function To provide combustion air into the burner chamber and to exhaust flue gas 1 Fan speed failure causing abnormal sounds with or without combustion in the l operation Failure events 2 Unexpected working caused by the connectors of the fan motor getting wet 3 Drops out from the bottom of the combustion chamber K3 1 T K3 does not function properly 2 Failure to ignite or abnormal ignition 3 Unstable combustion conditions RENE the fan motorfails 1 Visual inspection connection breakage of wires or dust causing electrical shortage 2 Voltage check proper range of voltages shown below Effects on the T if fan motor fails DC 110 160V Input DC 13 17V Input DC 2 0 6 5V Input Verify the fan motor speed using the Diagnostics Mode of the TM RE10 temperature remote controller See Section 12 1 for details 15 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 4 Gas valve assembly T K3 Part 105 Takagi Part EKK1W Checkpoint Opens and closes the gas pathways of the T K3 main and solenoid gas valves Modulates the gas flow from the gas inlet proportional gas valve 1 Gas
48. or any soot on the rod Check the connection of ground wire make sure there is firm three failed attempts at contact to the ground of the T K3 in this case the wire is contacted to the manifold surface a ae PCB fault During operation more than 1 uA through the flame rod wire orange Flame rod fault insulated resistance 1 Check gas supply and pressure Refer to section 1 Error code isl 2 PCB fault shown after D No voltage to gas main solenoid valve MV three failed Normal DC78 100V between COM blue 8 3 light blue attempts at 2 No voltage to gas solenoid valve SV 1 Sen Normal DC78 100V between COM blue amp 9 green 3 No voltage to gas proportional valve V Go Normal DC1 7 15V between white amp red 3 Gas solenoid fault CD Main gas solenoid valve MV fault Normal 0 97 1 3k 9 between COM blue amp 3 light blue Gas solenoid valve SV1 fault Normal 0 97 1 9k 9 between COM blue amp 9 green 3 Gas proportional valve VGo fault Normal DC1 15V between white amp red 4 Check for soot on the flame rod D Clean the flame rod PCB fault During operation more than 1 uA through the flame rod wire orange Flame rog fault insulated resistance 35 CONFIDENTIAL T K3 Service Manual Ver 1 05 Error Codel Malfunction description Cancellation method 5 Disconnected damaged O H C F Refer to section 10 13 121 Visual inspection connection breakage of wires Normal 1
49. perature detecting device which prevents the pipes within the T K3 from freezing When this device detects temperatures below 36 5 F 2 5 C inside the T K3 power is supplied to the electric heaters to prevent the T K3 from freezing 1 ON failure Always senses freezing temperatures regardless of actual Failure event tem perature 2 OFF failure Never senses freezing temperatures Effects on the T K3 1 The freeze protection heaters will always be ON causing heat damage to components inside the T K3 2 The freeze protection heaters will never be able to turn on even under freezing thermostat fails temperatures causing freeze damage to the T K3 freeze protection 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 Color Number of Black Black ON mode 90 VAC 110 VAC and less than 10 wires itself OFF mode less than 1 VAC and more than 1MO Activation and deactivation temperatures of the T K3 s freeze protection system ON mode 36 5 F 6 3F 2 7 F 2 5 C 3 5 C 1 0 C OFF mode above 46 4 F above 8 C 33 5mm 1 3 8 31 CONFIDENTIAL T K3 Service Manual Ver 1 05 11 Fault Analvsis 8 Specifications Re marks 1 Proper range of values of voltage amp resistance shown below 2 Please refer to 3 Remove power Nature of Fault No displav on temperature remote contr
50. rt 4 EKKOS Checkpoint The overheat cutoff fuse contains solder with a melting point of 365 F 185 C Detects excessive temperatures within the T K3 especially around the heat exchanger and combustion chamber Upon detection communication between the computer board and gas valves will sever shutting down the T K3 instantly The 111 or 121 error code will display 1 Unable to detect the excessively high temperatures within the T K3 Effects on the T K3 if the overheat cutoff fuse fails Error codes when the fuse fails 1 Flames from burner may penetrate a ruptured damaged heat exchanger 2 Gas valves will not operate 1 Visual inspection connection breakage of wires 2 Check voltages and resistance proper range of values shown below Color Number of Blue Blue Less than 10 wires Solder will melt at temperatures exceeding 365 F 9F or 185 C 45 C 27 1 2 700mm 25 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 14 Freeze protection heaters 412 EKK2R 418 Inlet T9Keg Partit Ekk2P inet Checkpoint B1 Prevents the heat exchanger water valves and water pipes within the T K3 from freezing The heaters are but one of the freeze protection devices in the T K3 Open circuit failure ceramic heaters do not receive the voltage needed to heat up Failure event Effects on the T K3 Ceramic heaters do not activate allowing water contained in the heat exchanger if heaters fail to freeze
51. t off valve H 5 y Open all hot water taps in the house When the all water flow has ceased close all hot water taps G D a Drain plug E withfilter Gas ape i MAN Have a bucket or pan to catch the water from the Water Vave T K3 s drain plugs Unscrew the drain plugs to drain all the w ater out of the T K3 Wait a few minutes to ensure all water has completely drained from unit LF GAD Clean the filter Inspect the water filter located ine 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 w ater inlet Securely screw the drain plugs back into place Hand tighten only 64 CONFIDENTIAL T K3 Service Manual Ver 1 05 13 Components diagrams Case assemblv b atk oe w frs CONFIDENTIAL T K3 Service Manual Ver 1 05 Burner assembly 66 CONFIDENTIAL T K3 Service Manual Ver 1 05 Water way assembly CONFIDENTIAL T K3 Service Manual Ver 1 05 14 Partslist Description Common parts forother units EKK1D CASE ASSEMBLY FRONT COVER JUNCTION BOX SCREW M4X 12 SCREW WAW ASHER M4 X10 COATING SCREW M4X10 SCREW M4X 10 NYLONE CLAMP TRJr OS SP TH1 TK2 TRD20 TR1S OS SP TM1 TM199 TH1 TK2 TRD20 TR1S OS SP TM1 TM199 TH1 TK2 TRD20 TRJr TK1S OS SP TM1 TM199 TH1 TH1 BURNER ASSEMBLY COMBUSTION CHAMBER MANIFO
52. ted by follow ing the procedures below Adjusting the manifold pressure can cause unexpected combustion conditions N during operation which can cause a health hazard damage the T K3 and or shorten its lifespan Therefore changing the manifold pressure is not WABNING recommended unless there are very strong reasons to do so e g high elevation installations and w ith the consultation of Takagi USA Adjusting maximum manifold pressure 1 Ensure that T K3 is not is operation 2 Remove the screw off the manifold port of the T K3 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 w ater through the T K3 to activate its operation If presence of a gas leak is detected immediately shut off the T K3 and inspect the tube manifold connection otherw ise 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 INC REA SE or DEC REASE 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 6 After gas pressure has been set deactivate the T K3 remove the mano meter tube and replace the port screw Adjusting minimum manifold pressure 1 Ensure that T K3 is not is operation 2 Remove the screw off the manifold port of the T
53. the red light turns on Then press reset button on the GFI The 991 error code should then be cleared Increase button Decrease button Red light Press and hold the INC and DEC buttons simultaneously for at least 3 seconds 46 CONFIDENTIAL T K3 Service Manual Ver 1 05 12 4 Dipswitch settings There are two banks of dipsw itches upper and low er bank on the T K3 computer board 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 dipsw itch before changing any settings The functions of the upper bank of dipswitches 2 Allow adjustments of fan motor speed Enable Disable f feel m 3 Changing the T K3 s ON OFF mode Continuous Inter mittent er mee nce 4 6 fan motor Disable a FM speed is increas ed automatically by6 speed 5 Deactivation of the freeze protection firing Enable Disable Plc ome rere ES I nservi may for T K3 s installed in recirculation svstems Default Default 2 Direct vent setting Enable Disable preven mana aa CONFIDENTIAL T K3 Service Manual Ver 1 05 12 5 Assigning unit numbers in the Easv link svstem e Each T K3 in an Easy link system is assigned a random unit f except for the Master unit which is aw ays assigned as unit 1 This is why the T K3 s will not necessarily be numbered in order
54. ther the gas supply pressure is adequate Check for cross connections between cold water lines and hot water lines Fault of PCB in the T K3 D No voltage to gas solenoid valve SV2 Normal DC787 100V between COM blue 8 53 orange C No voltage to gas solenoid valve SV 3 Normal DC78 100V between COM blue amp 73 red 5 Gas solenoid valve SV2 fault D Disconnected wiring to gas solenoid valve SV2 Normal 1 37 1 9k amp between COM blue 8 53 orange C Disconnected wiring to gas solenoid valve SV3 Normal 0 97 1 7k between COM blue amp 73 red 6 PCB fault Em D No voltage to flow adjustment valve Normal DC7 16V between red black 7 Flow adjustment valve fault Normal 0 09 0 2k between red black 33 CONFIDENTIAL T K3 Service Manual Ver 1 05 Error Codel Malfunction description Cancellation method Turn off the power or water jsuppl C Checkpoint Check the dipswitch settings on PCB Error Code Malfunction description Cancellation method Warning for the 991 error code On the PCB press the INC and Refer to section 12 3 DEC buttons simultaneously for 3 sec Then turn the power off Diagnosis Checkpoint 1 Checkifthere is any blockage in the air inlet of the unit 2 Checkifthere is s any blockage along the exhaust run 031 Dipswitch setting fault Malfunction description Cancellation method A Turn off the power or water Ignition fa
55. up possibly causing the heat exchanger to burst E vs heaters fail 1 Visual inspection connection breakage of wires and the condition of the heaters 2 Check whether those are in the normal range as shown in the following table nd ot white White AC 90 110V during operation The T K3 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 the inlet pipe For the_outlet pipe For the inlet pipe For the heat exchanger Inlet Heater Heater 4 3 8 110mm i 26 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 15 Computer board T K3 Part f 701 Takagi Part EKK1L Checkpoint Function Controls the functions of most of the parts in the T K3 Faure event J Malfunctioning computer Effects on the T K3 A component s may not operate within the T K3 In most cases of computer if the computer board failure the whole T K3 does not operate at all board fails Error codes display Error codes when 701 721 741 991 761 during multi unit operation the computer board fails Visual ins Bp connection breakage of wires and or burn marks on the Diagnostic Color Number of wires 5 3 8 138mm 27 CONFIDENTIAL T K3 Service Manual Ver 1 05 10 16 Transformer T K3 Part f 702 Takagi Part EKHO9 Checkpoint At A2 To transform input voltage from 120VAC to 100VAC Every electrical component of the T K3

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