1. Residential Gas – Honeywell Valve - Thermopile Powered Series 300/301
2011 TRAINING DEPT. ASHLAND CITY TN.

2. Atmospheric Vented Category I Status LED Wrap-around Filter
Vents with metal B vent materials
Thermopiles (sometimes called a “Generator”) generate approximately 700 millivolt open circuit and 350 – 400 MV closed circuit. A thermopile is basically several thermocouples in one housing.
The status LED aids in lighting the pilot, gives operational information as well as troubleshooting diagnostic.
The base wrap around air filter allows air into the chamber through a large air intake surface. This needs to be inspected and cleaned occasionally.

3. Introduction Installation Operation Service
THIS PRESENTATION WILL COVER THESE 4 AREAS: INTRODUCTION , INSTALLATION, OPERATION AND SERVICE.

4. Gas Valve/Thermostat Status Codes LED Status Light
LABEL ON GAS VALVE/THERMOSTAT FOR QUICK REFERENCE TO LED CODES
PIEZO SPARK IGNITER.
750 MILLI-VOLT (MV) THERMOPILE – SOMETIMES CALLED “GENERATOR” OR “POWER PILE”.
Spark Igniter Button
Thermopile Powered

5. Propane Gas Valve/Thermostat Color Coding
ALSO, THE CONTROL GAS PRESSURE OPERATING LABLE ON THE RIGHT SIDE OF THE CONTROL WILL INDICATE THAT THE VALVE IS FOR PROPANE GAS.

6. Installation

7. Installation – Gas Supply
Maximum Supply Press.
Manifold Gas Press.
Natural
10.5 In WC
5.0 In WC
Propane
13.0 In WC
10.0 In WC
NOTE THAT THESE ARE NOT THE SAME THAT MANY MODELS HAVE USED IN THE PAST. ALSO, BE AWARE THAT NOT ALL OF THE HONEYWELL VALVES THAT WE USE ON OUR PRODUCTS WILL USE THESE PRESSURES.

8. Installation - Piping
NOTE LOCATION OF THE THERMAL EXPANSION TANK BETWEEN SHUT OFFS AND WATER HEATER INLET. FOR PROPER INSTALLATION OF THE EXPANSION TANK, TAKE A WATER PRESSURE READING, PUMP AIR INTO THE EXPANSION TANK TO MATCH THIS PRESSURE, INSTALL THE EXPANSION TANK NEAR THE WATER HEATER. DO NOT LEAVE THE TANK PRESSURE AT THE FACTORY PRESSURE!
A PRESSURE REDUCING VALVE WITH BYPASS IS NOT ALWAYS AN ADEQUATE “OPEN” SYSTEM. THE WATER PRESSURE ON THE WATER HEATER SIDE OF THE VALVE USUALLY HAS TO EXCEED THE SUPPLY WATER PRESSURE BY AT LEAST 2 PSI BEFORE THE PRESSURE WILL “BYPASS” FROM THE WATER HEATER SIDE BACK INTO THE MAIN WATER SIDE OF THE VALVE. IF MAIN PRESSURE IS 80 PSI OR GREATER, ALLOWING WATER HEATER SYSTEM PRESSURE TO REACH 82 PSI+ CAN STILL DAMAGE FIXTURES AND LESSEN THE LIFE OF THE WATER HEATER. OUR RECOMMENDED BUILDING WATER PRESSURE IS 50 – 60 PSI.
THE T&P HAS AN UNRESTRICTED DISCHARGE PIPE TO THE DRAIN AND THERE IS A DRAIN PAN. ALL WATER HEATERS WILL LEAK SOME DAY.
MISSING FROM THE ILLUSTRATION BUT OFTEN NECESSARY, IS A WATER TEMPERING VALVE (MIXING VALVE) ON THE HOT WATER OUTLET. WE RECOMMEND THIS WHENEVER THE CUSTOMER REQUIRES HIGHER THAN 125° WATER. (SIDE NOTE: REPLACING A 40 GALLON TANK OF 140 DEGREE WATER WITH A 40 GALLON TANK BUT 120 DEGREE WATER IS NEARLY THE EQUIVALENT OF INSTALLING A 25 GALLON REPLACEMENT TANK. WATCH FOR “LACK OF HOT WATER ISSUES”.)

9. Installation – Combustion Air
12.5 Cubic Feet of Air Per 1000 Btu
10 CU.
FT.
COMB.
AIR
1,000
BTU +
THESE PRODUCTS USE ROOM AIR FOR COMBUSTION. FOLLOW THE FUEL GAS CODE AND ANSI STANDARDS FOR ENSURING THAT SUPPLIES ARE ADEQUATE FOR ALL APPLIANCES AND EXHAUSTS IN THE ENCLOSURE.
LACK OF AIR FOR COMBUSTION IS IN THE TOP TEN REASONS FOR SERVICE CALLS AND WARRANTY CLAIMS – NOT A WARRANTY ISSUE.
2.5 CU.
FT.
EXCESS
AIR

10. Operation

11. Operation - Thermopile Powered
A grouping of thermocouples into one housing results in a “Thermopile” or “Generator”
Heat on the thermopile, generates 750 to 850 milli- volts (.750VDC) – open circuit.
When heated and connected to the gas valve, ours generates 350 or more mV - closed circuit.
A THERMOCOUPLE TYPICALLY READS A MAXIMUM OF 30 MILLIVOLTS – OPEN CIRCUIT AND 15 – 20 CLOSED CIRCUIT.

12. Operation - Lighting the Pilot
Note This Comment
THIS PROCESS IS DIFFERENT THAN THE WR OR ROBERTSHAW VALVE REQUIREMENTS AND CAN LEAD TO UNNECESSARY SERVICE CALLS.
TO LIGHT THE PILOT
1. TURN THE TEMPERATURE KNOB TO “PILOT”.
2. PUSH IN THE TEMPERATURE KNOB.
3. WHILE HOLDING THE KNOB “IN” TO ALLOW GAS TO THE PILOT, REPEATEDLY PUSH THE SPARK IGNITER BUTTON. ALLOW A COUPLE OF SECONDS BETWEEN TRIALS.
4. WHEN THE PILOT LIGHTS AND THE THERMOPILE IS GENERATING ADEQUATE MILLI-VOLTAGE, THE STATUS LIGHT WILL BLINK.
5. NOW YOU CAN RELEASE THE TEMPERATURE KNOB.

13. Operation – Lighting the Pilot
Note this comment
THE “NOTE” IS NOT EXACTLY CORRECT: A STEADY ON LIGHT ALSO APPLIES TO A THERMOPILE AS IT COOLS. IF THE THERMOPILE WAS HOT (GENERATING SOME MILLI VOLTAGE) THE LED WILL BE SOLID ON UNTIL MILLI VOLTAGE HAS DROPPED TO THE POINT OF RESETTING THE CONTROL. THIS WILL ALLOW A PILOT RELIGHT. THE LIGHT DOES NOT GO OUT IMMEDIATELY IF THE PILOT IS OUT OR VALVE IS TURNED TO :OFF”. IF THE PILOT FAILED TO LIGHT OR GOES OUT AFTER BEING LIT, THE PILOT CANNOT BE LIT OR RELIT UNTIL THE THERMOPILE COOLS AND THIS LIGHT GOES OUT.
CUSTOMERS FAMILIAR WITH OTHER GAS VALVES THAT WE HAVE/CURRENTLY USE ON OTHER PRODUCTS WILL TRY TO RELIGHT THE PILOT IMMEDIATELY AFTER NOTING THAT THEY RELEASED THE TOP KNOB TO SOON OR THE PILOT WENT OUT AFTER THE THERMOPILE HAD BEEN HEATED. THE PILOT WILL NOT LIGHT (NO GAS) AND THEY WILL ASSUME A SERVICE ISSUE EXISTS. ON THIS VALVE, THEY MAY HAVE TO WAIT SEVERAL MINUTES FOR THE LED LIGHT TO GO OUT BEFORE A SUCCESSFUL TRIAL TO LIGHT THE PILOT IS POSSIBLE.
The pilot cannot be relit if this steady LED light is still ON. The thermopile must cool to automatically reset the control.

14. Operation – Lighting the Pilot
Status Indicator
Blinking once every 3 seconds = pilot knob may be released and normal operation in HEAT mode.
Solid On – control has been turned Off – thermopile cooling
2 to 8 flashes every 3 seconds – error codes

15. Operation - Temperature Adjustment
Dial
Approx. Temp ° F
VAC 55
HOT
120
VERY HOT
155
ADD A MIXING VALVE IF TEMPERATURE IN EXCESS OF 120 DEGREES IS DESIRED.
(SIDE NOTE: REPLACING A 40 GALLON TANK OF 140 DEGREE WATER WITH A 40 GALLON TANK BUT 120 DEGREE WATER SETTING IS NEARLY THE EQUIVALENT OF INSTALLING A 31 GALLON REPLACEMENT TANK. WATCH FOR “LACK OF HOT WATER ISSUES”.)
“A” APPROXIMATELY 130 DEGREES
“B” APPROXIMATELY 140 DEGREES
“C” APPROXIMATELY 150 DEGREES
120°F is the recommended setting

16. Review Questions Natural Gas – maximum gas supply pressure?
10.5 Inches WC
AN “INCH OF WATER COLUMN” IS LITERALLY THE PRESSURE REQUIRED TO RAISE THE LEVEL OF A COLUMN OF WATER 1 INCH AND IS APPLIED TO BOTH GAS AND AIR DRAFT READINGS ON WATER HEATERS.

17. Review Questions
2. Since these products get combustion air directly from outdoors, indoor air supply does not matter?
They do NOT use air directly from outdoors. They use room air for combustion and therefore room air quality and quantity is very important.

18. Review Questions
3. Thermopile – This is a misspelling of thermocouple?
No – a thermopile is like a grouping of thermocouples into one housing. This results in a much stronger DC milli-voltage output from the heated end of the thermopile to the gas valve.

19. Review Questions
4.Thermopiles receive electrical power from a transformer?
No – pilot heat on the end of the thermopile generates electricity – millivolts. A maximum of 750 MV Vs a thermocouple which normally has a maximum output of 30MV.

20. Review Questions
5. Millivolts are AC or DC?
Direct Current

21. Review Questions
6. When I see the pilot light through the sight glass, I can release the pilot knob?
No, you must wait for the LED to flash indicating the milli-voltage from the thermopile circuit has reached an adequate level to power the gas valve/thermostat control functions.
JUST AS YOU MUST CONTINUE TO HOLD THE TOP KNOB DOWN ON A THERMOCOUPLE EQUIPPED MODEL UNTIL MILLI-VOLT OUTPUT IS STRONG ENOUGH TO HOLD IN THE INTERNAL ELECTROMAGNET OF THE CONTROL, YOU MUST CONTINUE TO HOLD IN THE TEMPERATURE KNOB UNTIL THE THERMOPILE GENERATES ENOUGH MILLI-VOLTAGE TO HOLD OPEN THE INTERNAL PILOT GAS VALVE. THE LED LIGHT WILL FLASH WHEN THIS HAS BEEN REACHED.

22. Service FOLLOW GOOD SERVICE SOLVING PROCEDURES:
GET MODEL, SERIAL NUMBER AND A GOOD DESCRIPTION OF THE SERVICE ISSUE AND ERROR CODE FROM THE CALLER.
WHEN YOU ARRIVE AT THE SITE AND CAN SEE THE WATER HEATER, DO A SITE INSPECTION FOR POSSIBLE GAS, VENTING, WATER OR AIR INSTALLATION PROBLEMS
NOTE ANY ERROR CODES AND ASSUME THAT THE WATER HEATER PARTS ARE DOING WHAT THEY ARE SUPPOSED TO DO.
TEST AND CORRECT THE PROBLEM.
ALWAYS ASK YOURSELF “WHY DID THIS CONTROL OR SAFETY DO ITS JOB? CORRECT THE SOURCE OF THE PROBLEM.

23. Service - Combustion Chamber
COMBUSTION AIR IS DRAWN INTO THE CHAMBER FROM BELOW THE WATER HEATER AND THROUGH THE FLAME-TRAP.
THE WATER HEATER WILL ALSO HAVE A WRAP AROUND AIR FILTER AT THE BASE WHICH THE END USER NEEDS TO INSPECT AND CLEAN AS NECESSARY.
IT IS VERY IMPORTANT THAT THE DOOR SEAL BE PROPERLY INSTALLED AND TIGHT TO THE CHAMBER WALL. AN IMPROPERLY INSTALLED SEAL CAN RESULT IN THERMAL SWITCH ACTIVATION, HEAT DAMAGE TO THE SEAL AND LOSS OF THE FVIR PROTECTION.

24. Service - Burner Assembly
MANUAL RESET THERMAL SWITCH IN SERIES WITH 750 MV THERMOPILE. THIS SWITCH ACTIVATES ON HIGH COMBUSTION CHAMBER TEMPERATURES – NORMALLY DUE TO LACK OF AIR OR A FLAMMABLE VAPOR IGNITION. THE END USER OR SERVICE PERSON SHOULD ALWAYS INVESTIGATE “WHY” THIS SWITCH HAS OPENED BEFORE RESETTING THE SWITCH.
ALSO NOTE THAT THE PILOT CAN BE LIT WHEN THIS THERMAL SWITCH IS OPEN IF THE TEMPERATURE KNOB IS BEING HELD IN WHILE IN THE “PILOT” POSITION. THE PILOT WILL GO OUT IMMEDIATELY WHEN THE KNOB IS RELEASED AND YOU WOULD NOT GET THE FLASHING RED LED.

25. Service - Supply Gas Pressure Test
DYNAMIC GAS PRESSURE SHOULD BE MEASURED WITH ALL APPLIANCES OPERATING THAT USE THE COMMON GAS SUPPLY.
W.C. = INCHES OF WATER COLUMN.
Burner Off – Static Pressure
9.85 In W.C.
Burner On – Dynamic Pressure
8.90 In W.C.
(Natural Gas)

26. Service – Manifold Gas Pressure
3/16” ALLEN WRENCH TO REMOVE GAS PRESSURE TAP PLUG
NOTE ¼” X 3” NIPPLE TO OTHER FITTINGS. PRESSURE TAP IS RECESSED.
MANIFOLD GAS PRESSURE SHOULD NORMALLY BE % OF LABEL. THE LABEL SAYS 5.0 INCHES W.C. FOR THIS NATURAL GAS MODEL SO THIS READING SHOULD BE DOUBLE CHECKED FOR METER ACCURACY OR HIGH SUPPLY GAS PRESSURE.
See Gas Valve Label Or Model and Rating Plate For Proper Reading
Pressure Test Fittings

27. Service - LED Diagnostic Codes
CAN DISPLAY MULTIPLE ERROR CODES. HIGHER NUMERIC CODE WILL FLASH FIRST.
FLASH 3 AND 6 WOULD BE USED FOR OTHER ADAPTATIONS OF THIS CONTROL
0 FLASHES - LOSS OF PILOT ON A UNIT THAT HAD BEEN OPERATING SHOULD NOT BE AN AUTOMATIC “TRY TO RELIGHT IT” WITHOUT INVESTIGATING THE “WHY” OF WHY THIS IS NECESSARY – LACK OF AIR OR THE PRESENCE OF FLAMMABLE VAPORS POSSIBLY.
If you have to reset the thermal switch (TCO), always check for flammable vapors or clean the filter and flame trap before relighting.

28. Service
AT A LATER DATE, CODE 7 WILL ADVISE THAT THE FRONT PORTION OF THE GAS CONTROL VALVE/THERMOSTAT BE REPLACED. UNDER WARRANTY, THE ENTIRE VALVE IS CURRENTLY REPLACED.
NORMAL FLASHES:
0 = CONTROL OFF/PILOT OUT – POSSIBLE THE THERMAL SWITCH HAS OPENED DUE TO BLOCKED WRAP AROUND FILTER OR FV IGNITION OCCURANCE.
1 = NORMAL OPERATION – IF THIS IS NOT ACHIEVED: LACK OF GAS, PLUGGED PILOT ORIFICE, PIEZO NOT SPARKING OR NOT SPARKING TO PILOT GAS, LOOSE THERMOPILE LEADS, FAULTY THERMOPILE.
CONTINUOUS = GAS CONTROL/THERMOSTAT IS SHUTTING DOWN. THERMOPILE IS COOLING DOWN TO THE RESET TEMPERATURE. LIGHT MUST GO OUT BEFORE TRYING TO RELIGHT THE PILOT. THIS COULD TAKE SEVERAL MINUTES
ERROR CODE FLASHES:
2 = THERMOPILE VOLTAGE LOW. CHECK OUTPUT, OPEN CHAMBER THERMAL SWITCH. CHECK FOR FV IGNITION, HIGH AMBIENT AIR TEMPERATURE, LOOSE CONNECTIONS, REPLACE THERMOPILE IF NECESSARY.
4 = WATER TEMP OVERHEAT – REPLACE CONTROL
5 = WATER TEMPERATURE SENSOR FAIL – REPLACE CONTROL
7 = CONTROL FAILURE – REPLACE CONTROL
8 = GAS VALVE FAILURE – REPLACE CONTROL

29. Service – Connections Check From Thermal Switch (Red)
Igniter Button
From Thermopile
(White)
CHECK FOR ANY LOOSE CONNECTIONS TO GAS VALVE AND COMBUSTION CHAMBER THERMAL SWITCH.
MANIFOLD PRESSURE WILL BE 5.0” WC ON NATURAL GAS AND 10.5“ W.C. PROPANE.
APPROXIMATELY 1.5” W.C. PRESSURE DROP THOUGH THE VALVE ON NATURAL GAS AND 1.0” W.C. ON PROPANE.
THE MANIFOLD CONNECTION TO THE GAS VALVE IS LEFT HAND THREAD FOR PROPANE.
Igniter Wire
Manifold Press. Tap

30. Service - Wrap Around Air Filter
THE WRAP AROUND AIR FILTER MUST BE CLEANED AS NECESSARY TO ALLOW COMBUSTION AIR UNDER THE WATER HEATER AND INTO THE CHAMBER.
Wrap Around Air Filter Must Be Kept Clean

31. Service - Thermopile Powered
A grouping of thermocouples into one housing results in a “Thermopile” or “Generator”
Heat on the thermopile, generates 750 to 850 milli- volts (.750VDC) – open circuit.
When heated and connected to gas valve, ours generates 350 or more mV - closed circuit.

32. Disconnecting Thermopile
Disconnect wires from gas valve/thermostat
DISCONNECTING THERMOPILE LEADS FROM GAS VALVE/THERMOSTAT.

33. Service - Thermopile Check – Open Circuit
Knob held in to sustain gas to pilot
Multimeter testing of thermopile leads
From thermopile
From thermal switch
PILOT MUST BE HEATING THE END OF THE THERMOPILE. SINCE THERMOPILE LEADS ARE DISCONNECTED FROM GAS VALVE, THE KNOB MUST BE HELD IN TO ALLOW GAS TO CONTINUE TO THE PILOT.
THERMOPILE LEADS HAVE BEEN DISCONNECTED FROM GAS VALVE AND MULTIMETER PROBES INSERTED INTO THE THERMOPILE LEADS.
WITH NO LOAD ON THE THERMOPILE (THERE MAY BE A LITTLE RESISTANCE BECAUSE THE FLAMMABLE VAPOR SENSOR IS STILL IN THE CIRCUIT. BUT THE READING IS STILL ABOVE OUR ANTICIPATED MINIMUM OF 750 MILLIVOLTS – MV - (.750VDC)
Generating .797VDC or 797 millivolt

34. Service - Thermopile Check – Closed Circuit
Pilot is lit
Thermopile circuit leads are connected to gas valve
Multi-meter leads inserted into thermopile circuit connections
PILOT IS HEATING THE END OF THE THERMOPILE
THERMOPILE IS UNDER LOAD BY BEING CONNECTED TO THE GAS CONTROL VALVE/THERMOSTAT.
MULTI-METER IS READING IN EXCESS OF THE 350MV THAT IS EXPECTED FOR PROPER OPERATION.
Generating .353VDC or millivolt

35. Service - Thermopile Check – Closed Circuit
2nd closed circuit test method
Pilot is lit
Multi-meter test lead to thermostat connection (white) and 2nd lead to thermal switch.
Red – from thermal switch
THE PREVIOUS TEST RESULTING IN 353 MILLIVOLT (MV) WOULD HAVE ALSO BEEN NEAR 600 MILLI-VOLT HAD THE THERMOPILE BEEN HEATED FOR A LONGER PERIOD IN THE FIRST PHOTO.
THE ADVANTAGE OF TESTING IN THIS METHOD IS ACCESS TO THE WIRE CONNECTION. THE POSSIBLE FAULT WITH TESTING THIS WAY IS TO NOT CATCH A FLAW IN THE WIRE OR WIRE CONNECTIONS FROM THE FVIR SENSOR AND THE THERMOSTAT CONNECTION.
FVIR SENSOR – FLAMMABLE VAPOR IGNITION RESISTANT SENSOR
.658VDC or 658 mV- well in excess of the minimum 350mV

36. Review Questions 9. I can not relight the pilot! Most likely reasons?
Thermopile still hot – wait for LED to go out,
open thermal switch (TCO),
plugged filter,
plugged flame-trap.

37. Review Questions
10. My multimeter says that the thermopile is generating nearly 30 milli-volts DC. Why won’t my pilot light.
30mv is a thermocouple reading value.
Check multimeter setting,
poor flame impingement on thermopile,
faulty thermopile.

38. Review Questions 11. My shower time has decreased significantly. Why?
A 40 gallon model set at 140°F was removed and a 40 gallon model set at 120° was installed.
A GALLON OF HOT WATER IS A GALLON OF STORED BTU. THIS EXAMPLE WOULD HAVE 20% FEWER BTU STORED IN ADDITION TO THE CONSUMER USING A HIGHER PERCENTAGE OF HOT GPM FLOW TO MAINTAIN THE AVERAGE 105° SHOWER WATER TEMPERATURE. THEREFORE LESS HOT WATER SHOWER TIME. INSTALL A TEMPERING VALVE IF HIGHER STORED WATER TEMPERATURES ARE DESIRED.

39. Atmospheric Vented, Residential Gas – Honeywell Valve - Thermopile Powered Series 300/301
2011 TRAINING DEPT. ASHLAND CITY TN.

40. www.hotwater.com for product specs and installation manuals.