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Intelli-Vent Control Information

1. Pressure Switch Descriptions Air pressure switches are described and referred to by their Contact State and Contact Action IE the switch on the left side in the illustration below is a normally open close on a fall pressure switch See page 7 for more information about other types of switches Normally Open Close on a Fall Normally Open Close on a Rise Sensing Port Above Diaphragm a fall in pressure or vacuum activates the switch Sensing Port Beneath Diaphragm Flexible Diaphragm a rise in pressure activates the switch Service Note Because one of the two air chambers is vented to the atmosphere the ambient in the surrounding area air pressure is critical Ambient air pressure can push or pull on the diaphragm through the vent port If the ambient air pressure is extremely high positive or low negative it may cause erratic pressure switch operation Direct vent installations will not eliminate this potential problem Tools Required for Testing A volt ohm multi meter Fieldpiece HS36 DMM digital multi meter or equivalent A digital manometer is also required to measure pressure and perform conclusive diagnostic tests Specifications range 15 0 W C to 15 0 W C resolution 0 01 W C Brands models recommended that meet these specifications include UEI model EM 200 and Extech model 406850 dual pressure reading digital manometers AHSA02307 3 of 8 Air Pressure Switch Testing OFF e
2. Power Vent Intellivent with FVIR Classroom Contents e 320988 000 Intellivent Service Handbook Technical Bulletin Intellivent with FVIR e Technical Bulletin Pressure Switches INTELLI VENT CONTROL INFORMATION When Used On Gas Residential Power Vented Water Heaters Printed in the USA 0605 Part No GTC 070 R3 Revision 2 includes updated troubleshooting information for error codes 3 4 and 6 Revision 3 includes updated troubleshooting for error codes 4 and 6 and technical bulletins INTELLI VENT TROUBLESHOOTING GUIDE INTELLI VENT FEATURES The Intelli Vent is a combination control incorporating all temperature control ignition control blower and ignitor control flame sensing and gas regulation into a single device Advanced Diagnostics Error Codes The Intelli Vent features advanced diagnostics with 15 specific error codes including reversed polarity and inadequate grounding notification Diagnostic information is conveyed via 6 LED lights on the control These error codes will help diagnose and repair the water heater quickly and accurately Tamper Resistant The Intelli Vent features tamper resistant temperature settings In order to access temperature settings both temperature adjust buttons must be pressed simultaneously for one full second to review the temperature settings Temperature settings are displayed by illuminating various combinations of LED lights Precise Temperature Contr
3. resistance ohms of a hot surface ignitor will increase over time If the resistance at room temperature is near 18 8 ohms consider replacing the ignitor as a preventative measure 1 of 5 AHSTBO02807 heater are secure Ensure the wall outlet is properly wired Ensure all internal 120 VAC wiring connections and wiring harness have no reversed wires 120 VAC hot wire must connect to the on off switch Ensure air pressure switch circuit wiring is correct and the air pressure switch is not jumpered Secure power to water heater check continuity of air pressure switch contacts with wires disconnected A If pressure switch contacts show continuity closed circuit replace the pressure switch B If pressure switch contacts are open and all wiring is correct turn the power off for 10 20 seconds then on again to clear the error code if the error code persists replace the Intelli Vent control Ensure the blower is running check for 120 VAC to the blower when the heating cycle begins check the wiring If the control does not energize the blower replace the Intelli Vent control If the blower fails to start when energized replace the blower assembly Ensure the air pressure switch sensing tube is properly connected not kinked or damaged Check continuity of vent temperature limit switch replace switch if contacts remain open under 160 F Ensure the correct size of vent pipe 2 3 4 was used per t
4. APPLY POWER TO APPLIANCE IS FIELD WIRING CORRECT CONTROL LOCK OUT DISPLAY ERROR 1 OR 2 YES CALL FOR HEAT PRESENT YES IS PROVEN OPEN WITHIN 5 SWITCH TO OPEN ay 27 DISPLAY ERROR 3 SECONDS YES BLOWER ON IS PRESSURE SWITCH PROVEN CLOSED WITHIN 5 SECONDS WAIT FOR PRESSURE NO SWITCH TO CLOSE DISPLAY ERROR 4 YES ONE HOUR LOCKOUT RETRIES FROM BEGINNING OF SEQUENCE IS IGNITOR OKAY TURN OFF BLOWER DISPLAY ERROR 5 YES IGNITOR ON FOR WARM UP TIME MAIN VALVE OPENS TURN OFF BLOWER ONE HOUR LOCKOUT AFTER POST PURGE 3 MORE RETRIES DISPLAY ERROR 6 FROM BEGINNING OF SEQUENCE FLAME SENSED DURING TRIAL MAIN VALVE CLOSES 1s FLAME SENSE MAINTAINED YES BLOWER INTER PURGE BLOWER OFF RETRIES UP TO 3 TIMES YES CALL FOR HEAT IS SATISFIED MAIN VALVE CLOSES BLOWER POST PURGE HEATER GOES INTO STANDBY MODE FROM BEGINNING OF SEQUENCE
5. ARON H nu Male Plug Air Pressure Switch Circuit 120 VAC Neutral Wire to Blower 120 VAC Hot Wire to Control A 4 Air Pressure Switch Circuit 5 120 VAC Hot Wire to Blower Black Resistor Wire 6 120 VAC Neutral Wire to Control between pin 3 and 4 There are two female Molex plug receptacles on the bottom of the Intelli Vent control Keep i in mind the receptacles female and plugs male are mirror images of each other in regard to pin number location and retaining clip orientation Pin numbers and corresponding component wiring are detailed above in relation to the retaining clip The male plug ends from the 6 conductor wire harness and 5 conductor ignitor assembly plug are shown above notice the raised ridges identifying the 1 2 and 3 pins A black marker was used to highlight these ridges for the photograph Service Notes The Black Resistor Wire on the ignitor assembly plug is used to provide proper sensory input in place of optional external variable resistance devices none are currently used This resistor wire must not be cut removed or jumpered The Intelli Vent control would interpret this as a component failure and lock out displaying error code 14 or 15 Pins and sockets inside the plugs and receptacles should be visually inspected to insure good connections are being made when servicing Always depress retaining clip when unplugging Molex connectors failure to
6. BURNER Side View 00602 ELEVATION IS MEASURED FROM LOWER LIP URED EXTENDS OUT FURTHER ON LOW NOX BURNERS STANDARD BURNER BURNER FLAME SENSOR Side View Ne IS MEASURED FROM UPPER LIP ON STANDARD BURNERS Technical Training Department Ashland City Tennessee O 2005 17 of 24 INTELLI VENT TROUBLESHOOTING GUIDE BURNER CHECK LIST REMOVE BURNER TO PERFORM THE FOLLOWING TESTS 1 Burner mounting screws Check the two mounting screws that hold the burner head to the main burner tube These screws being loose can cause poor burner grounding and diminished or lost flame sensing current which leads to burner short cycling and lockout 2 Ignitor assembly plug connection Check the 5 pin Molex plug and the female receptacle in the control body to insure all conductors are present and making good contact Wiggle both Molex plugs at the control body to check for poor connections if the Intelli Vent control is not responding for any reason 3 Ignitor assembly wires Check the three wires between the ignitor assembly and the Intelli Vent control Insure these wires are not cut or damaged Replace the Ignitor assembly if the wiring is damaged 4 ignitor assembly ceramic insulators Make a close visual inspection of the ignitor assembly insulators Insure the two ceramic insulators for the ignitor and flame sensor are not chipped or cracked Replace the ignitor assembly if these insulators are damaged or defective 5 Ignitor
7. Y Continuity Test With Ohm Meter Continuity Test With Ohm Meter Power Vent Residential Model BTH 120 250 Blocked Exhaust Switch Testing the performance of air pressure switches involves three procedures First Procedure is a normal state test to determine if the switch contacts are open or closed in the normal state see page 2 without pressure applied Power is turned off for this test The wires to the switch are disconnected A continuity test is then performed ohm meter between the wiring terminals on the switch If the switch is a normally open switch see page 2 the continuity test should indicate no continuity open If the result of this test indicated the contacts were closed the switch must be replaced Likewise if a normally closed switch s contacts tested open in its normal state it would also have to be replaced Note gaining access to the switch and it s wiring terminals may involve removing the switch opening a control box etc THE SECOND AND THIRD PROCEDURES ARE PERFORMED WITH THE BLOWER RUNNING Second Procedure is an operational test to determine if the switch contacts are open or closed while the blower is running and pressure is applied to the switch The wires to the switch remain disconnected and a continuity test is performed as in the first procedure above Ensure the wires ends do not touch short to ground Ensure the sensing tube is properly connected at both ends and test for continuity with the blower runn
8. code 3 should not return and the Intelli Vent control should energize the combustion blower Technical Training Department Ashland City Tennessee O 2005 10 of 24 INTELLI VENT TROUBLESHOOTING GUIDE ERROR CODE 4 PRESSURE SWITCH CIRCUIT REMAINS OPEN 00000 Pressure switch circuit see 7 remains open longer than 5 seconds after the combustion blower inducer fan was energized by the Intelli Vent control Blower may run continuously in this condition Check Repair Insure the blower is starting and coming up to speed if the Intelli Vent control will not energize the blower with the air pressure switch circuit open replace the Intelli Vent control see footnote page10 Insure pressure switch wiring is correct see wiring diagram page 7 Insure pressure switch sensing tube is not damaged kinked and is properly connected Insure vent system has been installed correctly insure the correct size vent pipe was used Insure the maximum number of elbows or equivalent feet of vent pipe has not exceeded the water heater manufacturer requirements Insure a vent termination restrictor was not installed on vent installations that do not require it Do not install this restrictor when it is not required See the A O Smith otate Product Notifications for vent restrictor usage at the end of this manual Clear any obstructions or restrictions in the exhaust vent or the intake air pipe Defective air pressure switc
9. label see image above Whether the switch activates on a rise or fall in pressure is the type of switch action this information is available here page 7 for most current residential and commercial fan assisted water heaters Contact the technical information center 800 527 1953 when the activation point and or switch action are not known Have the complete water heater Model Serial and Series number on hand before calling Taking Air Pressure Readings Disconnect the pressure sensing tube from the sensing port on the switch leave the other end connected Examine the sensing tube connection on the water heater check for wear leaks kinks or any kind of debris or condensate in the sensing tube repair replace as necessary Connect a digital manometer to the pressure switch end of the sensing tube as shown above Turn the power on and ensure a call for heat is active When the blower starts and comes up to full speed record the pressure reading Normally Open Switches Normally open air pressure switches must close their contacts after the blower is energized the pressure reading taken must reach or exceed the activation point pressure value for the pressure switch being tested or the contacts will not close Pressure reading taken DOES NOT reach activation pressure DO NOT replace the air pressure switch if the contacts do not close during second procedure The switch is not defective IE Residential power vent product the pressure s
10. less susceptible to damage Technical Training Department Ashland City Tennessee 2005 1 of 24 INTELLI VENT TROUBLESHOOTING GUIDE INTELLI VENT CONSTRUCTION Temperature Probe ECO 55 Supply Gas Connection Future side connect model is shown here Top connect models are in use currently Front amp Left Side View Manifold Gas Main Burner Connection e RH thread Natural e LH thread Propane 6 Pin Molex Plug Line Voltage Blower Voltage e Pressure Switch Bottom View 5 Pin Molex Plug Hot Surface Ignitor Flame Sensor Resistor Wire Technical Training Department Flame Sensor Silicon Nitride Hot Surface Ignitor 6 LED indicator lights Temperature Settings Wi Error Codes Diagnostics Temperature adjust buttons must be pressed together for one second to wake up the control in order to view or change temperature settings Manifold Gas Pressure Tap Control Information AN Ignitor Assembly Ashland City Tennessee O 2005 2 of 24 INTELLI VENT TROUBLESHOOTING GUIDE INTELLI VENT OPERATION 6 LED indicator lights Temperature Settings Error Codes Diagnostics PRE START UP CHECK LIST Correct polarity on electrical supply e Water heater is properly grounded e Owner s manual safety statements have been reviewed START UP PROCEDURE 1 Plug in water heater and turn on power All lights on t
11. residential and commercial If the water heater was factory equipped with a combustion blower or inducer fan by design the blower must running during the heating cycle Air pressure switches are used to provide verification or prove electrically that the blower is running and the vent and or combustion air piping is not blocked or restricted The ignition control on these fan assisted boilers and water heaters senses when the air pressure switch circuit is open or closed There is at least one air pressure switch in this circuit that has normally open contacts on all models see page 5 As the blower starts and comes up to speed the normally open contacts on this air pressure switch will close in response to changes in vent system pressure At the beginning of a heating cycle the ignition control will check if the air pressure switch circuit is open before the control energizes the blower motor The ignition control will check the air pressure switch circuit a second time to insure it is closed after the blower is energized The ignition control then monitors this circuit during the heating cycle to insure the circuit remains closed If this circuit opens even for a split second during the heating cycle the control will close the gas valve immediately to insure safe operation In this way an ignition control can perform three critical diagnostic checks using a single air pressure switch 1 Verify the normally open air pressure switc
12. the two air chambers is vented to the atmosphere the ambient air pressure in the installed space is critical If the ambient air pressure is below atmospheric outdoor air pressure it will pull on the pressure switch diaphragm If the ambient air pressure is above atmospheric it will push on the pressure switch diaphragm In either condition the pressure switch will not operate as designed if the pressure imbalance is severe enough Correcting an air pressure imbalance between the installation space and the outdoors can be achieved by providing adequate make up air openings Direct vent installations will not eliminate this potential problem Technical Training Department Ashland City Tennessee 2005 21 of 24 INTELLI VENT TROUBLESHOOTING GUIDE AIR PRESSURE SWITCHES DIFFERENT TYPES SWITCH CONTACTS SWITCH ACTION Normally Open NO Close on a fall in pressure Normally Closed NC Open on a rise in pressure E UI Open on a fall in pressure The switches shown here are all SPST switches SPST single pole single throw Power Vent and Power Direct Vent residential products use the first type shown below Normal State Activated State Normally open contacts close on a fall in pressure Technical Training Department Ashland City Tennessee 2005 22 of 24 INTELLI VENT TROUBLESHOOTING GUIDE AIR PRESSURE SWITCH TESTING E 2 Continuity test with ohm meter Taking an air pressure reading To test the performa
13. Commercial controls display error codes by flashing the LED lights on and off Important Service Installation Notes 1 Always turn power off for 10 to 20 seconds and then back on again to clear an error code before replacing an Intelli Vent control 2 When installing the water heater or a replacement Intelli Vent control do not use the control face as a handle to move the water heater or turn thread the control 3 When installing a replacement control do no pinch pull or cut exposed wires Troubleshooting Guide Notes Residential error code displays are shown on the left and commercial on the right for all 15 error codes that follow e LEDs filled in black indicate an Illuminated LED ERROR CODE 1 NO EARTH GROUND Inadequate or no earth ground sensed by Intelli Vent control Check Repair Insure the wall outlet is properly grounded e Insure all ground connections on the water heater are secure e Insure ground path wires if so equipped between wiring boxes and heater jacket are properly secured e Insure the ground green wire in the power cord is continuous with an ohm meter Technical Training Department Ashland City Tennessee 2005 9 of 24 INTELLI VENT TROUBLESHOOTING GUIDE ERROR CODE 2 REVERSED POLARITY Power supply to Intelli Vent control has reversed polarity Check Repair Insure the wall outlet is properly wired e Insure all internal 120 VAC wiring connections on th
14. M BEGINNING OF SEQUENCE IS IGNITOR OKAY TURN OFF BLOWER DISPLAY ERROR 5 YES IGNITOR ON FOR WARM UP TIME TURN OFF BLOWER ONE HOUR LOCKOUT AFTER POST PURGE 3 MORE RETRIES DISPLAY ERROR 6 FROM BEGINNING OF SEQUENCE MAIN VALVE OPENS FLAME SENSED DURING TRIAL MAIN VALVE CLOSES IS FLAME SENSE MAINTAINED YES BLOWER INTER PURGE BLOWER OFF RETRIES UP TO 3 TIMES YES CALL FOR HEAT IS SATISFIED MAIN VALVE CLOSES BLOWER POST PURGE HEATER GOES INTO STANDBY MODE FROM BEGINNING OF SEQUENCE Technical Training Department Ashland City Tennessee 2005 8 of 24 INTELLI VENT TROUBLESHOOTING GUIDE INTELLI VENT TROUBLESHOOTING GUIDE Error Codes amp Diagnostics The Intelli Vent control will not have any LED lights illuminated during normal operation sleep mode for the life of the water heater When an LED is illuminated it draws attention to the water heater and the need to have it serviced There are 15 different diagnostic error codes the Intelli Vent control is capable of displaying by illuminating various combinations of LED lights All 15 are covered in the troubleshooting guide that follows The same combination of LED lights are used for error codes on residential and commercial controls though the way they are displayed differs slightly Residential controls display error codes via constant illumination of the LED lights
15. PERATURE CUTOFF ECO ACTIVATED Water temperature in the tank exceeded 195 F and activated the ECO Check Repair Turn the power off for 10 20 seconds and then on again to clear this error code Residential control replace the control if the error code cannot be cleared Commercial control cool water temperature below 120 F cycle power off and on to reset control Replace the control if the error code persists ERROR CODE 12 TEMPERATURE ADJUST BUTTONS STUCK CLOSED 12 V BC F The self diagnostic check detected temperature adjust button stuck closed Check Repair Make sure no objects are leaning against the front of the control e Lightly press and release each of the buttons once e If the above actions do not clear the error the control will continue to regulate water temperature at the last setting but you will not be able to change settings unless you replace the Intelli Vent control ERROR CODE 13 TEMPERATURE PROBE OPEN OR SHORTED The self diagnostic test has detected the water temperature sensor thermistor is either open or short circuited Check Repair Turn the power off for 10 20 seconds then on again to clear this error code This part of the control cannot be replaced or serviced If the error code cannot be cleared the Intelli Vent control must be replaced Technical Training Department Ashland City Tennessee O 2005 14 of 24 INTELLI VENT TROUBLE
16. SHOOTING GUIDE ERROR CODE 14 RESISTOR WIRE OPEN OR SHORTED Ignitor Assembly Plug Male End The self diagnostic test found a problem with the black resistor wire on the ignitor assembly plug the resistor wire is open or shorted see 6 Check Repair e Insure the black resistor wire is not cut missing and is installed between pins 3 amp 4 of the ignitor assembly plug Replace ignitor assembly if damaged or defective e Unplug the ignitor assembly plug from the control Check the resistance of the black resistor wire between pins 3 amp 4 with an ohm meter A If the reading taken is less than 2000 or more than 1 7 million ohms replace the ignitor assembly B If the reading taken is between 2000 and 1 7 million ohms replace the Intelli Vent control ERROR CODE 15 RESISTOR WIRE RESISTANCE OUT OF TOLERANCE Y BC DEF 000009 Ignitor Assembly Plug Male End The self diagnostic test determined the resistance of the black resistor wire on the ignitor assembly plug is not within tolerance see 6 Check Repair e Unplug the ignitor assembly plug from the control Check the resistance of the black resistor wire between pins 3 amp 4 with an ohm meter A Ifthe reading taken is more than 50 000 ohms replace the ignitor assembly B Ifthe reading taken is less than 50 000 ohms replace the Intelli Vent control Technical Training Department Ashland City Tennessee 2005 15 of 24 INTELLI VENT TROUBLE
17. SHOOTING GUIDE TECHNICAL BULLETIN IGNITION AND FLAME FAILURE A 022 04 amp 5 021 04 COMBINED This technical bulletin has been prepared to help diagnose and repair ignition and flame failure problems with White Rodgers Intelli Vent equipped water heaters Procedures to verify correct flame sensor alignment burner assembly condition and flue restrictor baffle position are outlined in this bulletin These procedures should help to identify and repair most ignition and flame failure problems Always verify an adequate supply of fuel gas manifold gas pressure and combustion air when experiencing ignition or flame failure Procedures for verifying an adequate supply of fuel gas and combustion air are detailed in the residential gas service handbook A O Smith part number TC 049 R3 State Water Heaters part number STC 080 available through your local A O Smith or State Water Heaters sales representative or as free download from the web sites www aosmithwaterheaters com www statewaterheaters com If it is determined there is not a sufficient supply of combustion air or fuel gas resolve these problems first The test procedures outlined in this technical bulletin presume there is an adequate supply of both fuel gas and combustion air FLAME SENSOR ALIGNMENT Intelli Vent equipped standard recovery 40 amp 50 gallon residential water heaters The lower lip or edge of a low NOx burner extends out further than it does on a standa
18. age for 40 000 Btu Power Vent Models This bulletin will simplify vent termination restrictor usage for the 40 000 Btu power vent models and allowable venting distances Power vent models 40 000 Btu manufactured prior to November 2004 serial number K04 are shipped with a vent kit that includes a 2 restrictor 1 24 inside opening and 2 tee These kits used for 2 vent installations up to 33 equivalent not to exceed 33 feet feet of vent pipe 2 restrictor is not needed if the vent run is longer than 33 equivalent feet and a 3 restrictor and 45 degree elbow for 3 vent installations of any vent length up to the maximum distance of 38 equivalent feet These restrictors are to be installed in the vent termination tee or elbow if the vent is less than distances listed above In November 2004 serial number L04 the 2 restrictor in the old vent kit was replaced with a new 2 restrictor 1 74 inside opening and the 3 restrictor was dropped from the kit The venting distance requiring the use of the restrictor was reduced to 20 feet or less with this change This means that if the vent distance is greater than 20 feet the restrictor is not needed The series numbers 100 amp 101 did not change with the revision to these kits However the termination tee that we have been buying using since November 2004 has the 2 restrictor installed in the tee If the vent length is more than 20 feet the 2 restrictor in not needed and the r
19. blows the flame away from the flame sensor causing burner short cycling The Intelli Vent control would lockout after 3 failed attempts and display error code 6 A dislodged flue restrictor or baffle can also allow too much heat to flow into the combustion blower and vent system leading to 1 Vent temperature limit switch contacts opening during the heating cycle preventing the thermostat from satisfying The Intelli Vent control closes the gas valve immediately if this switch activates 2 Heat damage to the combustion blower and or vent system components The outer and inner combustion chamber access covers and the fiberglass insulation between the outer jacket and the combustion chamber must also be installed correctly If not installed properly this could also cause excessive air turbulence inside the combustion chamber Insure these covers are installed correctly and the fiber glass insulation is not removed or tucked pushed away from these openings when servicing Insure the flue baffle flue restrictor combustion chamber access covers and fiber glass insulation between the outer jacket and combustion chamber are all installed properly to minimize ignition and flame failure conditions Technical Training Department Ashland City Tennessee O 2005 19 of 24 INTELLI VENT TROUBLESHOOTING GUIDE TECHNICAL BULLETIN AIR PRESSURE SWITCHES A 023 04 amp 5 024 04 COMBINED Air pressure switches are used on all fan assisted gas fired water heaters
20. combustion blower or inducer fan is running 3 Verify the vent combustion air piping length is not excessive and or obstructed Paul Stewart Technical Training Department A O Smith Water Products Company Ashland City Tennessee AHSA02307 1 of 8 Air Pressure Switch Construction Normal State Activated State open switch contacts closed switch contacts Sensing Port Wiring Terminals Switch Contacts NI Internal Linkage A I gt Flexible Diaphragm Vent Port Air Pressure Switch Operation Air pressure switches activate in response to pressure sensed through a tube One end of this tube attaches to the pressure switch sensing port the other end attaches to a pressure sensing port somewhere on the water heater IE the vent system blower assembly A flexible diaphragm divides the body of the switch into two air chambers The sensing port is attached to one air chamber The other air chamber is vented to the atmosphere which allows the diaphragm to move Internal linkage attaches the switch contacts to the diaphragm with sufficient pressure applied diaphragm movement will activate the switch contacts Contact States The state of the contacts refers to whether or not the switch contacts are open or closed Closed contacts will allow electricity to flow through the switch because there is a continuous conductive path through the switch contacts Open contacts will not allow electricity to flow t
21. do so can damage plug connection Technical Training Department Ashland City Tennessee O 2005 6 of 24 INTELLI VENT TROUBLESHOOTING GUIDE H3MO 18 NOILSNENOD 1OH1NOO WO YIMO 18 OL G3M0d LIOA 0621 1013007 03 8JIM E1NSN OWA 021 J MOIG OF 9JIM JOH OVA 01 WNDU YINMSG dnssald JV 51261002 uado H21IMS IUNSSIHd HIV 0 WIM JOH IVA OZL 1SNYHXI 13450718 s1281u02 pasoja Ajjewsou J8MO g 8JIM OVA 01 HJLIMS LIAN UE nap 84ns58Jg Iy JHNLYHIdMNSL LNIA HOLIMS 5534 ONNOHS SHIM OL TYHLNAIN zi Lb J 19v1d3938 1084 LNO9 OL H3MOd LIOA 0cl 3 1TviWaa YOJIMS HUI YM peddinb3 sjepoly weibeig uorpoeuuo Ashland City Tennessee O 2005 Technical Training Department 7 of 24 INTELLI VENT TROUBLESHOOTING GUIDE INTELLI VENT SEQUENCE OF OPERATION APPLY POWER TO APPLIANCE IS FIELD WIRING CORRECT CONTROL LOCK OUT DISPLAY ERROR 1 OR 2 YES CALL FOR HEAT PRESENT YES IS PRESSURE SWITCH PROVEN OPEN WITHIN 5 SECONDS WAIT FOR PRESSURE NO SWITCH TO OPEN DISPLAY ERROR 3 YES BLOWER ON IS PRESSURE SWITCH PROVEN CLOSED WITHIN 5 SECONDS WAIT FOR PRESSURE NO SWITCH TO CLOSE DISPLAY ERROR 4 YES ONE HOUR LOCKOUT RETRIES FRO
22. e water heater are not reversed 120 VAC hot wire should connect to the on off switch e Insure the wiring harness between the Intelli Vent control and the wiring box has no crossed wires with an ohm meter see 7 e Double check all ground connections insure they are clean tight and intact ERROR CODE 3 PRESSURE SWITCH CIRCUIT REMAINS CLOSED TPressure switch circuit see 7 remaining closed for more than 5 seconds after heating cycle is activated Blower does not start Check Repair e Insure air pressure switch circuit wiring is correct and the air pressure switch is not jumpered e Turn off power and unplug the water heater from wall outlet Disconnect both wires from the air pressure switch terminals Check between the wiring terminals of the air pressure switch with an ohm meter for continuity A If pressure switch contacts show continuity closed circuit replace the pressure switch B If pressure switch contacts show open circuit and all wiring is correct replace Intelli Vent control t To verify a closed air pressure switch circuit is preventing the heat sequence from advanc ing IE the combustion blower is not being energized Turn off power amp unplug the water heater from the wall outlet Disconnect one wire from the air pressure switch tape off end of wire insure this wire does not touch ground Plug the water heater back in and turn the power switch back on If a call for heat is still present error
23. ed to restore operation The following should be done by a qualified service person after the hazard has been removed 1 Manual reset is accomplished by first turning off power to the water heater for 10 seconds 2 Restore the power to the water heater 3 Within 10 seconds of restoring power press the two temperature adjust buttons simultaneously until the left green Vacation LED begins to blink approx 5 second delay Once the Vacation LED begins to blink release both buttons 4 Again within 10 seconds press both temperature adjust buttons simultaneously until the Vacation LED is on steady approx 5 second delay 5 Release the two buttons the microcomputer will clear the FVS lock out and normal operation will then be restored A O Smith Water Products Company AHSTBO2807 Ashland City Tennessee 2006 4 of 5 Technical Training Department Intelli Vent Trouble Chart FVIR AOS fm TB A028 06 A O SMITH FVIR INTELLI VENT TROUBLESHOOTING CHART LED STATUS PROBLEM SOLUTION LDO Lint Dust and Oil lock Check clean intake air screen on the base ring of the out condition water heater Check clean the dilution air screen on the blower assembly Air pressure switch circuit is Opening repeatedly during one heating cycle May be caused by the air pressure switch and or the vent temperature limit switch these two switches are wired together in a series circuit Check clean the flame arrestor
24. els by month end as inventory levels begin to diminish The new heaters will have different blower baffle and burner assembly no NOx screen on the burner Additional copies are available from the Ashland City Advertising Department Prepared by the A O Smith State Water Heater Technical Training Department Ashland City Tennessee TB A028 06 A O SMITH FVIR INTELLI VENT TROUBLESHOOTING CHART LED STATUS PROBLEM SOLUTION Inadequate or no earth ground 1 Ensure the wall outlet is properly grounded sensed by the Intelli Vent 2 Ensure all ground connections wires on the water A O Smith Water Products Company Ashland City Tennessee O 2006 Power supply to Intelli Vent control has reversed polarity Pressure switch circuit remaining closed for more than 5 seconds after heating cycle begins Blower does not start Service Note Secure power disconnect one wire from the air pressure switch or the vent temperature limit switch Turn power back on blower should start Pressure switch circuit remains open longer than 5 seconds after the blower is energized Blower may run continuously in this condition Service Note To learn more about performing Air Pressure Switch tests visit our web site www hotwater com to download technical bulletin TB A023 06 Air Pressure Switches The Intelli Vent control has detected an open ignitor circuit Service Note Ignitors are wearing parts the
25. ent Ashland City Tennessee 2005 18 of 24 INTELLI VENT TROUBLESHOOTING GUIDE FLUE BAFFLE amp FLUE RESTRICTOR CHECK Flue baffle assembly shown to the left Insure this is assembled and installed properly This can become dislodged during transport Always check the flue baffle assembly if the water heater has been laid on its side during transport Some power vent residential models are equipped with flue restrictors in addition to the flue baffles installed on all models The flue restrictor and flue baffle are engineered to precisely regulate the flow of flue gases through the flue pipe This maximizes the amount of heat conducted into the water through the walls of the flue pipe The flue restrictor and baffle will also affect the velocity of air being drawn into and through the combustion chamber PE Flue Restrictor Correctly Installed i H 3 RR 4 i 5 1 Failure To Ignite 2 Short Cycling Burner 3 Blower Vent Overheating If the flue restrictor is dislodged as shown in the left illustration above the velocity of air flowing through the combustion chamber will increase This can cause air turbulence inside the combustion chamber that leads to 1 Fuel gas being swept away from the ignitor leading to ignition failure failure to ignite The Intelli Vent control would lockout after 3 failed attempts and display error code 6 2 Ignition occurs but the air turbulence
26. estrictor must be removed from the tee or the pressure switch will not make and the heater will not operate The restrictor s affect is resistance or restriction and on short vent runs this helps maintain energy factors If used on longer vent runs 2 pipe over 20 feet it adds too much restriction and the pressure switch will not let the heater operate With all of that said we are about to switch to a new series of power vent models series 102 amp 103 that will not use a restrictor in the vent termination You should start seeing this new series of power vent models by month end as inventory levels begin to diminish The new heaters will have different blower baffle and burner assembly no NOx screen on the burner Om WATER HEATERS The Expert s Choice 500 LINDAHL PARKWAY ASHLAND CITY TN 37015 Product Notification No 5425 Date 10 21 04 Vent Termination Restrictor Usage for 40 000 Btu Power Vent Models This bulletin will simplify vent termination restrictor usage for the 40 000 Btu power vent models and allowable venting distances Power vent models 40 000 Btu manufactured prior to November 2004 serial number K04 are shipped with a vent kit that includes a 2 restrictor 1 inside opening and 2 tee These kits are used for 2 vent installations up to 33 equivalent not to exceed 33 feet feet of vent pipe 2 restrictor is not needed if the vent run is longer than 33 equivalent feet and a 3 restrict
27. for one hour Cycle the power to the water heater off and on to reset Service Note Ignitors are wearing parts the resistance ohms of a hot surface ignitor will increase over time If the resistance at room temperature is near 18 8 ohms consider replacing the ignitor as a preventative measure Self diagnostic tests have found a problem with the gas valve driver circuit internal microprocessor or other internal circuits Flame signal has been sensed out of proper sequence Water temperature in the tank has exceeded 195 F and has activated the ECO The self diagnostic check detected one or both of the temperature adjust buttons are stuck The self diagnostic test has detected the water temperature sensor thermistor is either open or shorted 20f5 5 02807 PROBLEM SOLUTION Gas supply is turned off pressure too low Ensure supply and manifold gas pressures are within requirements in the installation manual Manifold gas pressure is non adjustable if pressure is off by more than 0 3 W C replace the Intelli Vent control 2 Low supply voltage should be 115 125 VAC 3 Ensure flame sensor is making good contact with the burner flame ensure flame is steady see 8 below Ensure the flame sensor is clean use ultra fine steel wool or Scotch Brite pad to clean flame sensor Ensure the hot surface ignitor is positioned to provide consistent ignition Check for any cracks in ig
28. h Check pressure switch contacts with ohm meter during blower operation contacts should close show continuity after blower starts and comes up to speed If air pressure switch contacts are not closing Take air pressure reading see page 23 with a digital manometer at the sensing port on the blower Compare to manufacturer s specification for switch If pressure reading taken is at or beyond activation point according to manufacturer s specification for the switch replace air pressure switch If pressure reading taken does not reach activation point for switch Check for restrictions too many elbows or too many equivalent feet of vent intake air pipe Check for dirt debris on blower wheel Insure vent termination restrictor was not installed if it was not required See 5th bulleted item above Flue gas temperature in blower assembly is excessive pressure switch circuit is open due to vent temperature limit switch activating see wiring diagram page 7 Determine cause flue baffle restrictor missing damaged or not installed correctly amp make repairs Defective vent temperature limit switch this is a normally closed switch that opens its contacts on a rise in temperature Turn off power and disconnect wires to the vent temperature switch With the switch at room temperature 77 F check for continuity between the two wiring terminals on switch with an ohm meter If switch contacts are open at room temperature replace the switch Tec
29. h contacts are not stuck closed or jumpered 2 Verify the combustion blower or inducer fan is running 3 Verify the vent and or combustion air piping remain free of restrictions Pressure switch construction operation testing the various types of pressure switches and their wiring are explained in this bulletin Technical Training Department Ashland City Tennessee 2005 20 of 24 INTELLI VENT TROUBLESHOOTING GUIDE AIR PRESSURE SWITCH CONSTRUCTION The switch below has normally open switch contacts that close on a fall in pressure Normal State Activated State Wiring terminals Sensing port NS Switch contacts Diaphragm Vent port AIR PRESSURE SWITCH OPERATION Air pressure switches activate in response to changes in air pressure sensed through a plastic tube attached to a sensing port on the water vent system and or blower housing The diaphragm divides the body of the switch into two air chambers The air chamber the sensing port is attached to is sealed The other chamber is vented to the atmosphere which allows the diaphragm to move up and down There is linkage that attaches the switch contacts to the diaphragm so that when the diaphragm moves the contacts are activated The term activate means to change state If the contacts are normally open activating the contacts will cause them to close If the contacts are normally closed activating the contacts will cause them to open Service Note Because one of
30. he control will come on for about 1 5 seconds All lights will then turn off If the stored water is above 70 F residential and the control setting has not been increased from it s factory setting nothing more will happen Residential controls are factory set at 70 F the vacation setting per ANSI requirements Commercial controls are factory set at 120 F 2 Wake Up the control by holding down both of the temperature adjust buttons at the same time for about one second then release the buttons and the LED lights will indicate the current temperature setting 3 Push then release the hotter temperature adjust button repeatedly to increase the water temperature setting and the colder temperature adjust button to decrease the setting THE RECOMMENDED STARTING TEMPERATURE IS 120 F oee the illustration on the following page indicating which temperature setting corresponds to the various combinations of LED lights SLEEP MODE NORMAL OPERATION Without any further user input the control will go back into the sleep mode in 30 seconds All LED indicator lights will turn off This is the normal operating mode Technical Training Department Ashland City Tennessee 2005 3 of 24 INTELLI VENT TROUBLESHOOTING GUIDE TEMPERATURE SETTINGS Residential and commercial Intelli Vent controls differ in appearance The far left LED light is green on the residential control and the remaining 5 LEDs are yellow On the commercial cont
31. he installation manual for vent length Ensure maximum number of elbows or equivalent feet of vent pipe has not exceeded maximum limits 5 Ensure there are no obstructions in the vent pipe 6 Check air pressure switch performance check pressure with a digital manometer check continuity of contacts see service note in left column If the switch proves defective replace the air pressure switch and or the blower assembly as required If air pressure switch performance test results prove the air pressure switch is working properly and error code 4 persists replace the Intelli Vent control Check wiring to the hot surface ignitor replace ignitor assembly if wiring is damaged or worn Check ignitor assembly plug and the socket on the Intelli Vent body for good connection Replace ignitor assembly and or control if necessary Check resistance of ignitor at room temperature 77 F at the plug end Replace ignitor if resistance is not within 11 5 and 18 8 ohms at room temperature If results from the above tests were good and error code 5 persists replace the Intelli Vent control Technical Training Department Intelli Vent Trouble Chart FVIR AOS fm TB A028 06 A O SMITH FVIR INTELLI VENT TROUBLESHOOTING CHART LED STATUS A O Smith Water Products Company Ashland City Tennessee 2006 Ignition flame failure The water heater has reached the maximum number of retries and is currently locked out
32. here is no continuity through the switch contacts The state of the contacts open or closed can be verified confirmed with an ohm meter An ohm meter is required to perform conclusive diagnostic tests on air pressure switches With air pressure switches the term normal state refers to whether or not the switch contacts are open or closed when there is no pressure applied to the switch Switches can be normally open or normally closed abbreviated NO or NC in technical literature The activated state of a switch is the opposite of the normal state A normally open switch in it s activated state is closed A normally closed switch in it s activated state is open Air pressure switches are described by their normal state and by their contact action which is covered on the following page AHSA02307 2 of 8 Air Pressure Switch Operation cont Contact Actions The action of the contacts refers to what causes the switch to activate to change from it s normal state to its activated state See page 2 On an air pressure switch this can be either a rise or fall in pressure As the illustrations below indicate locating the sensing port above or below the flexible diaphragm facilitates these operational differences The contact action is further described to convey whether the contacts will open or close when the pressure sensed is sufficient to activate the switch contacts IE close on a fall in pressure
33. hing that can potentially emit flammable vapors from the area and store it properly in a different location Ensure power to the water heater is turned off Remove the FV sensor from it s bracket on the base ring of the water heater and disconnect both wires to the sensor Take a resistance reading between the two wiring terminals of the FV sensor and note the resistance values Perform this test once in the area by the water heater and a second time outdoors after allowing the sensor to acclimate to the outdoor atmosphere for 5 minutes Service Note These resistance readings should be taken using an ohm scale above70 000 ohms If the resistance of the FV sensor is above 70 000 ohms during the indoor test only and the resistance reading taken in the outdoor atmosphere dropped below 70 000 ohms Re check the area surrounding the water heater for substances that could be emitting flammable vapors Remove any such substances from the area and store them properly in a different location Repeat step 2 If the resistance of the FV sensor is above 70 000 ohms during the indoor and outdoor tests replace the flammable vapor sensor If the resistance of the FV sensor was below 70 000 ohms during the indoor and outdoor tests and all the steps above have been performed replace the Intelli Vent control Flammable Vapors Sensed FVS Reset Procedure After a flammable vapor lockout has been initiated a manual reset must be perform
34. hnical Training Department Ashland City Tennessee 2005 11 of 24 INTELLI VENT TROUBLESHOOTING GUIDE ERROR CODE 5 IGNITOR FAILURE DE F 02000009 0000 The Intelli Vent control has detected an open ignitor circuit Check Repair e Check all wiring to the hot surface ignitor e Check 5 pin Molex ignitor assembly plug and receptacle on the Intelli Vent body for a good connection Repair or replace parts if necessary e Check resistance of ignitor with an ohm meter between pin 1 and 2 on the ignitor assembly plug Replace ignitor if resistance is not within 11 5 and 18 8 ohms e f above checks are good and ignitor resistance is within specification replace the Intelli Vent control ERROR CODE 6 IGNITION FLAME FAILURE The water heater has reached the maximum number of retries or recycles and is currently locked out for one hour Cycle the power to the water heater off and on to reset Check Repair Gas supply is off or too low of pressure to operate Insure manifold gas pressure is present and within requirement Insure the flame sensor is making good contact with the burner flame See the Ignition and Flame Failure bulletin on page 16 and the burner check on page 18 Insure the flame sensor is clean use steel wool to clean sensor Insure flue restrictor on models so equipped see page 19 and flue baffle are installed properly Flue restrictor must be flush on top of flue pipe A di
35. ing at full speed Note the condition of the switch contacts whether open or closed Normally open air pressure switches must close during operation and normally closed air pressure switches must remain closed throughout the heating cycle on A O Smith fan assisted water heaters This information can usually be found in the sequence of operation section of the owner s manual and or service manual for the product Contact the A O Smith technical information center 800 527 1953 for more information Normally open switches If the air pressure switch being tested is a normally open switch it must close it s contacts activate before ignition can occur If the continuity test indicates a normally open switch s contacts have closed while the blower is running the switch is operating correctly If the continuity test indicates the switch contacts are remaining open while the blower is running the third pressure test procedure will have to be performed This will determine if the switch is defective or if the switch contacts are failing to close because the pressure being sensed has not reached the activation point for the switch This is covered on the next page Normally closed switches If the air pressure switch being tested is a normally closed switch the switch contacts must remain closed throughout the heating cycle If the continuity test indicates a normally closed switch s contacts remain closed while the blower is running the switch is o
36. ld be done with the power off and the wires to the switch removed If the switch is a normally open switch and the continuity test showed continuity through the contacts the switch is defective and must be replaced A normally closed switch would be defective if it showed no continuity under these conditions An operational test would be performed during blower operation with the wires to the air pressure switch removed and the sensing tube attached at both ends With an ohm meter check continuity between the two wiring terminals on the pressure switch after the blower comes up to speed If the pressure reading taken previously is at or beyond the activation point for the pressure switch and the pressure switch contacts do not activate the pressure switch is defective and must be replaced Technical Training Department Ashland City Tennessee O 2005 23 of 24 INTELLI VENT TROUBLESHOOTING GUIDE AIR PRESSURE SWITCH CIRCUITS Air Pressure Switch Circuit Residential Power Vent Power Direct Vent Blocked Exhaust Switch Vent Temperature Limit Switch Normally Open Contacts Normally Closed Contacts Close on a Fall in Pressure Open on a Rise in Temperature Q TE Molex Plug Ge Technical Training Department Ashland City Tennessee 2005 24 of 24 PRODUCT NOTIFICATION 500 LINDAHL PARKWAY ASHLAND CITY TN 37015 1 866 362 9898 www aosmithwaterheaters com No ARGPNO305N Date March 18 2005 Vent Termination Restrictor Us
37. nce of an air pressure switch you must know the design activation point This will be a given pressure value either negative in a vacuum or a positive pressure Contact the technical information center for this information or to locate a service handbook for the product you are working on A O Smith Water Heaters 800 527 1953 State Water Heaters 800 365 0577 Have the complete model serial and series number on hand Testing air pressure switch performance requires a digital or incline manometer that will read pressures at the expected activation point to within 1 100th of an inch of water column W C at times Digital manometers are typically less expensive and quicker to use than incline manometers Manufacturers include Dwyer UEI and Bacharach A good range of operation would be 15 00 W C to 15 00 W C Must be sensitive to 1 100th W C With the sensing tube removed from the vent system sensing port attach the manometer to the port start the water heater and when the blower comes up to speed record the pressure reading If the pressure reading does not reach the activation point for the pressure switch the vent system must be checked for restrictions too many elbows or too many equivalent feet of piping Consult the owners manual for complete venting requirements Inspect clean the blower as necessary The state of the air pressure switch contacts can be checked with an ohm meter for continuity A normal state test wou
38. nitor assembly ceramic insulators replace ignitor assembly if damaged Check resistance of ignitor at room temperature 77 F at the plug end Replace ignitor if resistance is not within 11 5 and 18 8 ohms at room temperature Ensure the correct size of vent pipe 2 3 4 was used per installation manual for vent length Using larger pipe than required may cause excessive air turbulence in the combustion chamber Turn the power off for 10 20 seconds then on again to clear these error codes If any of these error codes persist or cannot be cleared replace the Intelli Vent control Turn the power off for 10 20 seconds and then on again to clear this error code Replace the Intelli Vent control if this error code persists Turn the power off for 10 20 seconds then on again to clear this error code Replace the control if the error code persists Press and release temperature adjust buttons If the above action does not clear the error the control will continue to regulate water temperature at the last setting However settings will no longer be adjustable the control should be replaced Turn the power off for 10 20 seconds then on again to clear this error code Replace the Intelli Vent control if this error code persists Technical Training Department Intelli Vent Trouble Chart FVIR AOS fm Flammable Vapor Sensor Location Testing A O Smith Water Products Company Ashland City Tennes
39. ol The Intelli Vent controls temperature electronically Tighter cut out and cut in differentials produce less temperature swing than standard residential controls Temperature Probe Thermistor The temperature probe houses the ECO and a temperature sensor which is a thermistor Thermistors are thermally sensitive variable resistors A change in water temperature changes the resistance measured in ohms of the thermistor The Intelli Vent control interprets this change in resistance as a change in temperature and uses this information to activate and deactivate a call for heat Silicon Nitride Ignitor The Intelli Vent control uses a silicon nitride ignitor which is more durable than the silicon carbide ignitors previously used Body oils transferred to the ignitor during handling will not damage silicon nitride ignitors nor will minor bumps or drops This ignitor is also highly resistant to damage caused by condensation Adaptive Learning Technology Adaptive Learning Technology refers to the programed control of voltage to the ignitor The Intelli Vent varies voltage to the ignitor and learns to use the lowest voltage necessary that insures consistent ignition Lower voltage increases ignitor life Water Resistant While not being a water proof control the Intelli Vent control does have a greater degree of resistance to water damage than previous controls Wiring connections are on the bottom of the control and
40. open or closed There will always be at least one air pressure switch that has normally open contacts see pages 7 amp 8 As the blower starts and comes up to speed the normally open contacts of this switch should activate contacts will close in response to the pressure it senses as long as there are no adverse operating conditions Normal Operating Sequence Pressure Switch Circuit Power Vent Power Direct Vent Cyclone Master Fit BTN BTI models 1 At the beginning of a heating cycle the ignition control will verify the air pressure switch circuit is open before the control energizes the blower motor 2 After successfully completing the above open circuit verification step the ignition control will energize the blower the control will then check the air pressure switch circuit a second time after the blower is energized This time the pressure switch circuit must be verified closed The ignitor would not be energized unless this circuit closes after the blower is energized 3 The ignition control monitors this circuit during the entire heating cycle to ensure it remains closed If this circuit opens even for a split second during the heating cycle the control will close the gas valve and stop the heating cycle By monitoring the air pressure switch circuit an ignition control can perform critical operational checks such as 1 Verify normally open air pressure switch contacts are not stuck closed or jumpered 2 Verify the
41. or and 45 degree elbow for 3 vent installations of any vent length up to the maximum distance of 38 equivalent feet These restrictors are to be installed in the vent termination tee or elbow if the vent is less than distances listed above In November 2004 serial number L04 the 2 restrictor in the old vent kit was replaced with a new 2 restrictor 1 74 inside opening and the 3 restrictor was dropped from the kit The venting distance requiring the use of the restrictor was reduced to 20 feet or less with this change This means that if the vent distance is greater than 20 feet the restrictor is not needed The model numbers did not change with the revision to these kits However the termination tee that we have been buying using since November 2004 has the 2 restrictor installed in the tee If the vent length is more than 20 feet the 2 restrictor in not needed and the restrictor must be removed from the tee or the pressure switch will not allow the heater to operate The restrictor s affect is resistance or restriction and on short vent runs this helps maintain energy factors If used on longer vent runs 2 pipe over 20 feet it adds too much restriction and the pressure switch will not let the heater operate With all of that said we are about to switch to a new series of power vent models series 102 amp 103 that will not use a restrictor in the vent termination You should start seeing this new series of power vent mod
42. perating correctly If the continuity test indicates the switch contacts are opening after the blower starts the third pressure test procedure will have to be performed This will determine if the switch is defective or if the switch contacts are opening because the pressure being sensed has reached or exceeded the activation point This will be covered on the next page AHSA02307 4 of 8 Air Pressure Switch Testing cont The pressure activation point for the air pressure switch below is 1 07 W C inches water column This is a negative pressure value in a vacuum z a i Blocked Vent Air Pressure Switch Blocked Vent Switch Pressure Test Residential Power Vent Model Vertex Residential Power Vent Model Third Procedure is a pressure test and requires a digital manometer capable of reading positive and negative pressures good range of operation would be 15 00 W C to 15 00 W C inches water column with a resolution of 0 01 W C Recommend the UEI model EM 200 or Extech model 406850 dual pressure digital manometers not shown here To determine if an air pressure switch is operating properly you must know the pressure activation point for the switch and whether it activates on a rise or a fall in pressure The activation point is a given pressure value and may be a positive or negative in a vacuum pressure This information is often provided on the switch
43. rd burner Flame sensor gap and elevation are measured from the lower lip on low NOx burners and from the top lip on standard burners as illustrated on the following page The A O Smith Water Heater specifications given here are for standard recovery residential power vent and power direct vent 40 and 50 gallon models GPSH 40 GPSH 50 GPDH 40 GPDH 50 Call the A O Smith Water Heaters technical information center 800 527 1953 for information on other models The State Water Heater specifications here are for standard recovery residential power vent and power direct vent 40 and 50 gallon models PR6 40 amp 50 XCVIT natural or CCVIT propane PR6 40 amp 50 XBPDT natural or CBPDT propane Call the State Water Heaters technical information center 800 365 0577 for information on other models A Smith ELEVATION m NATURAL GAS PROPANE GAS NATURAL GAS PROPANE GAS GPSH 40 amp 50 040 GPDH 40 amp 50 ELEVATION PRe40 amp 50XICBPDT 047 Technical Training Department Ashland City Tennessee 2005 16 of 24 INTELLI VENT TROUBLESHOOTING GUIDE FLAME SENSOR ALIGNMENT CONT FLAME SENSOR GAP LOW NOX BURNER FLAME SENSOR GAP IS MEASURED FROM LOWER LIP WHICH EXTENDS OUT FURTHER ON LOW NOX BURNERS BURNER Side View STANDARD BURNER BURNER FLAME SENSOR Side View N GAP IS MEASURED FROM UPPER LIP ON STANDARD BURNERS FLAME SENSOR ELEVATION LOW NOX BURNER
44. resistance test Check the ignitor resistance with an ohm meter set on a low scale Ignitor resistance should be between 11 5 and 18 8 ohms If the resistance of the ignitor is not within this range replace the ignitor Worn or damaged ignitors can cause ignition failure and control lockout after three failed ignition attempts 6 Flame sensor condition Insure the flame sensor is free of rust and corrosion clean the sensor with steel wool Sand cloth can be used be sure to clean off any residue left by the sand cloth Rust or corrosion on a flame sensor will cause diminished or lost flame sensing current which leads to burner short cycling and control lockout after three failed ignition attempts 7 Flame sensor ignitor alignment Insure the flame sensor is aligned with the burner according to the specifications on the previous page of this bulletin A misaligned flame sensor can lead to diminished or lost flame sensing current which causes burner short cycling and control lockout after three failed ignition attempts If the flame sensor is aligned properly the ignitor should be positioned correctly also since both are fixed to a common assembly 8 Low NOx screen clearance On low NOx models insure the low NOx screen is not touching either the ignitor or the flame sensor when installed inside the combustion chamber This screen touching the flame sensor could cause a false flame sensing signal and control lockout Technical Training Departm
45. rol all six LEDs are yellow The residential control has a vacation temperature setting 70 F and it is referenced on the display There is no vacation setting on a commercial control The residential control uses an inverted triangle delta symbol above the third LED and uses A B and C as temperature set point references The commercial control places the inverted triangle above the far left LED and uses B C D E and F for temperature set point references Residential 1 v A B 000000 2 COOLER gt HOTTER DISPLAY APPROXIMATE WABC TEMPERATURE F 70 110 115 120 00908600 125 130 135 140 000066 145 OOOOOeO 150 OOOOOeOe 160 FLASHING Technical Training Department Commercial Y BC DEF man 000000 W COOLER gt HOTTER DISPLAY APPROXIMATE VBCODEF TEMPERATURE F 120 130 140 145 150 155 160 165 170 00009860 175 OO0O00 180 Ashland City Tennessee 2005 4 of 24 INTELLI VENT TROUBLESHOOTING GUIDE INTELLI VENT SPECIFICATIONS INTELLI VENT CONTROL SPECIFICATIONS Body 7e inch NPT inlet 7e inch inverted flare ou
46. see 2006 The self diagnostic test has detected the flammable vapor sensor is either open or shorted The Intelli Vent control is programed to lock out and display this error code if the resistance value it senses from the FV sensor is below 5 000 ohms or above 1 700 000 ohms Service Note To perform this test the ohm meter used must be capable of reading up to 2 000 000 ohms AHSTBO2807 3 of 5 TB A028 06 A O SMITH FVIR INTELLI VENT TROUBLESHOOTING CHART LED STATUS PROBLEM SOLUTION 1 Turn off power to the water heater Ensure all FV sensor wiring the ignitor assembly plug and the ignitor assembly socket on the bottom of the Intelli Vent control are making good contact Repair or replace any worn damaged components that are not making a good connection Restore power to the water heater if the error code has cleared place the water heater back in operation and allow it to cycle several times to ensure the problem has been resolved If the error code persists continue to step 3 below Turn off power to the water heater Remove the FV sensor from it s bracket on the base ring of the water heater and disconnect both wires to the sensor Take a resistance reading between the two wiring terminals of the FV sensor and note the resistance value Service Note Unless the ohm meter used has an auto range feature the resistance should be checked twice The first reading will be taken using an ohms scale abo
47. see the service note below Remove the blower assembly and check the flue baffle ensure the flue baffle is in good condition and properly installed reinstall as necessary and or replace the flue baffle if worn or damaged Ensure water heater is not over firing check burner orifice size ensure the correct orifice is installed replace as necessary Ensure water heater is not over firing check manifold gas pressure ensure manifold gas pressure is within 0 3 W C of the listed rating on the Intelli Vent control valve Manifold gas pressure is non adjustable if manifold gas pressure is off by more than 0 3 W C replace the Intelli Vent control Check the vent temperature limit switch if it is determined that the vent temperature limit switch is Opening its contacts at normal operating temperatures during the heating cycle replace the vent temperature limit switch Service Note the flame arrestor is accessible through the intake air opening in the base ring of the water heater with the intake air screen removed Use a non metallic household brush to clear away any lint or dust from the ceramic flame arrestor then vacuum the surface of the flame arrestor and the base ring air chamber thoroughly with a household vacuum cleaner A suitable vacuum hose attachment can be fabricated in the field using a short length of 1 2 PVC pipe with a short radius elbow on one end Use tape to temporarily seal it to the
48. sloged or missing flue restrictor baffle can cause excessive air turbulence in the combustion chamber sweeping all gas away from ignitor no ignition or the flame away from the sensor short cycling burner Insure vent termination restrictor see product notification sheets at end of this publication is installed when required e Insure the ignitor is positioned correctly for consistent ignition Low voltage to the water heater Should be 115 125 VAC Technical Training Department Ashland City Tennessee O 2005 12 of 24 INTELLI VENT TROUBLESHOOTING GUIDE ERROR CODES 7 8 9 INTERNAL CONTROL FAILURES Self diagnostic tests have found a problem with the gas valve driver circuit internal microprocessor or the internal circuits Check Repair Turn the power off for 10 20 seconds then on again to clear these error codes e lf any of these error codes persist or cannot be cleared replace the Intelli Vent control ERROR CODE 10 FLAME SENSED OUT OF SEQUENCE Flame signal has been sensed out of proper sequence Check Repair e Insure flame sensor ceramic insulator is not cracked replace ignitor assembly if defective urn the power off for 10 20 seconds and then on again to clear this error code e Replace the Intelli Vent control if this error code persists Technical Training Department Ashland City Tennessee 2005 13 of 24 INTELLI VENT TROUBLESHOOTING GUIDE ERROR CODE 11 HIGH TEM
49. sure Switch Types Contact States Normally Open NO Normally Closed NC Application Normal State Blocked Exhaust Air Pressure Switch Power Vent amp Power Direct Vent Residential Models Blower Prover Air Pressure Switch BTI BTN 120 400 Models Blocked Intake Air Pressure Switch Cyclone BTH 120 400 Models Blower Prover Air Pressure Switch Cyclone BTH 120 400 Models Blocked Exhaust Air Pressure Switch Cyclone BTH 120 400 Models Contact Actions Close on a rise in pressure Close on a fall in pressure Open on a rise in pressure Open on a fall in pressure Activated State Normally closed contacts open on a rise in pressure AHSA02307 7 of 8 Air Pressure Switch Circuit Residential Power Vent amp Power Direct Vent Water Heaters Blocked Exhaust Switch Vent Temperature Limit Switch Normally Open Contacts Normally Closed Contacts Close on a Fall in Pressure Open on a Rise in Temperature Q Molex Plug 4 Air Pressure Switch Circuit Cyclone Water Heater Blocked Inlet Switch Blocked Exhaust Switch Normally Closed Contacts Normally Closed Contacts Open on a Fall in Pressure Open on a Rise in Pressure CN6 Plug Control Board Blower Prover Switch Normally Open Contacts Close on a Rise in Pressure 6 Low Gas Pressure Switch Normally Open Contacts Close on a Rise in Pressure BTH 120 250 300 400 only AHSA02307 8 of 8 Intelli Vent Sequence of Operation
50. switch did reach or exceed the activation point pressure value for the switch the switch is defective and should be replaced Normally Closed Switches Current design residential power vent power direct vent and commercial BTI BTN models are not equipped with normally closed air pressure switches Cyclone BTH 120 400 models equipped with two normally closed air pressure switches a blocked inlet and blocked exhaust switch see pages 7 amp 8 Normally closed switches should remain closed at all times unless there is an operational problem Pressure reading taken DOES NOT reach the activation pressure If the test results for the second procedure indicated a normally closed switches contacts were opening during blower operation AND the pressure reading taken DOES NOT reach or exceed the activation point pressure value for the switch the switch is defective and should be replaced Pressure reading taken DOES reach the activation pressure If the test results for the second procedure indicated a normally closed switch contacts were opening during blower operation AND the pressure reading taken DOES reach or exceeds the activation point for the switch DO NOT replace the switch it is not defective Ensure the intake air or vent piping is not excessive and both are free of obstructions Always check the owner s manual vent installation section for proper intake air and vent pipe installation requirements AHSA02307 6 of 8 Air Pres
51. tlet RH thread natural LH thread propane Electrical Ratings 120 VAC 60 Hz 10 5 7 FLA Ignitor load 2 amps maximum Blower inducer motors 3 amps full load 4 amps locked rotor Max Inlet Max Inlet Gas Pressure Pressure 4 PSI maximum 140540000500 PSI 4 PSI maximum 140540000500 14 0 W C LLL Range 70 160 F Residential 120 180 F Commercial High Temp Cut Off ECO 195 F Residential single use control must be replaced 195 F Commercial resettable reset temp 120 F OPERATING SEQUENCE meee GAS PRESSURE REQUIREMENTS NATURAL GAS Supply gas e 4 5 to 5 0 W C minimum 14 0 W C maximum Always check control water heater label tManifold aas 3 5to 4 0 W C Always check control water heater label PROPANE GAS Supply gas e 11 0 W C minimum 14 0 W C maximum TManifold gas 10 0 W C T Manifold gas pressure is non adjustable Always verify correct main burner orifice before replacing a control for failing to maintain correct manifold pressure Technical Training Department Ashland City Tennessee 2005 5 of 24 INTELLI VENT TROUBLESHOOTING GUIDE INTELLI VENT WIRING CONNECTIONS FEMALE MOLEX RECEPTACLES BOTTOM OF CONTROL Hai gi ne c Ignitor Assembly Connections Wiring Harness Connections Female Receptacle Female Receptacle Ignitor hot wire Ignitor neutral wire esistor wire sistor wire Flame sense rod R Re
52. vacuum hose Additional Recommended Service Publications Power Vent service manual part number TC 048 R6 revision 6 or later Intelli Vent service manual supplement part number GTC 070 revision 3 or later Air Pressure Switches technical bulletin number TB A023 06 Visit our web site at www hotwater com to download the above service manual and supplement Revision numbers for these service publications are designated by R3 R4 R6 R7 etc as a suffix to the part numbers IE GTC 070 R4 A O Smith Water Products Company AHSTB02807 Technical Training Department Ashland City Tennessee O 2006 5of5 Intelli Vent Trouble Chart FVIR AOS fm A O Smith Training Department Technical Bulletin TB A023 06 Air Pressure Switches This bulletin has been prepared to explain and illustrate the construction operation and testing procedures for various types of air pressure switches used on residential and commercial tank type water heaters Air pressure switches are used on all fan assisted gas fired water heaters in our product line Air pressure switches are used to verify that operational conditions are being met IE the blower is running or the vent combustion air piping length is not excessive or obstructed Air pressure switches are usually wired together with other switches into a series circuit see page 8 The ignition control constantly monitors the state of the air pressure switch circuit whether it is
53. ve 1 700 000 ohms The second reading is taken using an ohms scale just above 5 000 ohms If resistance of the FV sensor is lower than 5 000 ohms replace the FV sensor If resistance of the FV sensor is above 1 700 000 ohms replace the FV sensor If the resistance of the FV sensor is above 5 000 ohms and lower than 1 700 000 ohms and all the above steps have been performed ensure the wiring and plug between the sensor and the Intelli Vent control are not damaged or worn replace the ignitor assembly if the wiring and or plug are damaged worn If the wiring and plug are in good condition replace the Intelli Vent control valve Technical Training Department Intelli Vent Trouble Chart FVIR AOS fm TB A028 06 A O SMITH FVIR INTELLI VENT TROUBLESHOOTING CHART LED STATUS PROBLEM SOLUTION The self diagnostic test has 1 Turn off power to the water heater Carefully check detected the presence of flammable vapors The Intelli Vent control is programed to lock out and display this error code if the resistance value it senses from the FV sensor is above 70 000 ohms but remains below 1 700 000 ohms The Intelli Vent control is ina hard lock out condition that cannot be reset by cycling power to the water heater See the instructions below for the reset procedure the surrounding area for any substances such as gasoline paint paint thinners or cleaners that could emit flammable vapors Remove anyt
54. witch on these products is a normally open closes on a fall in pressure switch see page 7 If the activation point for the switch is 1 07 W C and the actual pressure reading taken was 0 85 W C the actual pressure has not reached the activation point The switch contacts will not close until the pressure reaches or exceeds 1 07 W C AHSA02307 o of 8 CV Blocked Exhaust Switch Pressure Test Blocked Exhaust Switch Pressure Test Cyclone BTH 300 400 Models Cyclone BTH 120 250 Models Air Pressure Switch Testing Third Procedure Normally Open Switches cont Pressure reading taken DOES NOT reach the activation pressure cont Ensure the sensing tube is connected securely and not blocked with any debris or condensate Ensure the tube is not kinked or leaking On residential power vent models check vent piping for excessive length or number of elbows check for obstructions in the vent pipe On Cyclone BTH models ensure the minimum vent pipe length requirement 7 BTH 120 250 15 BTH 300 400 has been met Ensure the blower wheel is clean on all models This can become dirty over time or during construction on new water heaters and cause operational problems Pressure reading taken DOES reach the activation pressure If the test results for the second procedure indicated the normally open switch contacts did not close and the pressure reading taken during the third procedure indicated the pressure sensed by the

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