Post on 26-Mar-2015
Residential Gas – Honeywell Valve - Thermopile Powered
Series 300/301
Atmospheric Vented
Category IStatus LED
Wrap-around Filter
• Introduction
• Installation
• Operation
• Service
Gas Valve/Thermostat
Spark Igniter Button
LED StatusLight
Status Codes
Thermopile
Powered
Gas Valve/Thermostat
Propane Gas Valve/Thermostat Color Coding
Installation
Installation – Gas Supply
Gas Maximum Supply Press.
Manifold Gas Press.
Natural 10.5 In WC 5.0 In WC
Propane 13.0 In WC 10.0 In WC
Installation - Piping
Installation – Combustion Air
• 12.5 Cubic Feet of Air Per 1000 Btu
1,000BTU1,000BTU +
10 CU.FT.
COMB.AIR
10 CU.FT.
COMB.AIR
2.5 CU.FT.
EXCESSAIR
2.5 CU.FT.
EXCESSAIR
• Operation
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.
Operation - Lighting the Pilot
Note This Comment
Note this
comment
Operation – Lighting the Pilot
The pilot cannot be relit if this steady LED light is still ON. The thermopile must cool to automatically reset the control.
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
Operation - Temperature Adjustment
Dial Approx. Temp ° F
VAC 55
HOT 120
VERY HOT
155
120°F is the recommended setting
Review Questions
1. Natural Gas – maximum gas supply pressure?
10.5 Inches WC
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.
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.
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.
Review Questions
5. Millivolts are AC or DC?
Direct Current
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.
Service
Service - Combustion Chamber
Service - Burner Assembly
Service - Supply Gas Pressure Test
Burner Off – Static Pressure
9.85 In W.C.
Burner On – Dynamic Pressure
8.90 In W.C.
(Natural Gas)
Service – Manifold Gas Pressure
See Gas Valve Label Or Model and Rating Plate For Proper
Reading
Pressure Test Fittings
Service - LED Diagnostic Codes
If you have to reset the thermal switch (TCO), always check for flammable vapors or clean the filter and flame trap before
relighting.
Service
Service – Connections Check
Igniter Wire
From Thermopi
le(White)
From Thermal Switch (Red)
Manifold Press. Tap
Igniter Button
Service - Wrap Around Air Filter
Wrap Around Air Filter Must Be Kept Clean
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.
Disconnecting Thermopile
Disconnect wires from gas valve/thermostat
Service - Thermopile Check –Open Circuit
Knob held in to
sustain gas to pilot
Multimeter testing of
thermopile leads
Generating .797VDC or
797 millivolt
From thermopile
From thermal switch
Service - Thermopile Check –Closed Circuit
Generating .353VDC or 353.4 millivolt
Thermopile circuit
leads are connected
to gas valve
Pilot is lit
Multi-meter leads
inserted into
thermopile circuit
connections
Service - Thermopile Check –Closed Circuit
.658VDC or 658 mV- well in excess of
the minimum 350mV
Multi-meter test lead to
thermostat connection
(white) and 2nd lead to thermal
switch.
Pilot is lit
2nd closed circuit test method
Red – from
thermal
switch
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.
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.
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.
Atmospheric Vented, Residential Gas – Honeywell Valve -
Thermopile PoweredSeries 300/301