Troubleshooting Gas Control (820 Millivolt Gas Vale) - Vermont Castings RHEDV25 Installation Instructions & Homeowner's Manual

Troubleshooting the Gas Control System
NOTE: Before trouble shooting the gas control system, be sure external gas shut off is in the "On" position.
WARNING: Before doing any gas control service work, remove glass front.
SYMPTOM
1. Spark ignitor will not light
2. Pilot will not stay lit after
carefully following lighting
instructions.
3. Pilot burning, no gas to
main burner
4. Frequent pilot outage
problem.
10000801
Vermont Castings, Majestic Products RHEDV Direct Vent Insert
SIT NOVA 820 Millivolt Valve
POSSIBLE CAUSES
A. Defective or misaligned
electrode at pilot.
B. Defective ignitor (Push Button)
A. Defective pilot generator
(thermocouple), remote wall
switch.
B. Defective automatic valve
A. Wall switch or wires defective
B. Thermopile may not be
generating sufficient
millivoltage.
C. Plugged burner orifice.
D. Defective automatic valve
operator.
A. Pilot flame may be too low
or blowing (high) causing the
pilot safety to drop out.
B. Possible blockage of the vent
terminal.
CORRECTIVE ACTION
Using a match, light pilot. If pilot lights, turn off
pilot and push the red button again. If pilot will not
light - check gap at electrode and pilot-should be
1/8" to have a strong spark.
Push Piezo Ignitor Button. Check for spark at
electrode and pilot. If no spark to pilot, and elec
trode wire is properly connected, replace ignitor.
Check pilot flame. Must impinge on thermo
couple/thermopile. Note: this pilot burner assem
bly utilizes both-a thermocouple and a thermopile.
The thermocouple operates the main valve
operation (On and Off). Clean and or adjust pilot for
maximum flame impingement on thermopile and
thermocouple.
Turn valve knob to "Pilot". Maintain flow to pilot;
milivolt meter should read greater than 10 mV. If
the reading is okay and the pilot does not stay on,
replace the gas valve. Note: An interrupter block
(not supplied) must be used to conduct this test.
Check wall switch and wires for proper connec
tions. Jumper wire accross terminals at wall
switch, if burner comes on, replace defective wall
switch. If okay, jumper wires across wall switch
wires at valve, if burner comes on, wires are faulty
or connections are bad.
1. Be sure wire connections from thermopile at
gas valve terminals are tight and thermopile is
fully inserted into pilot bracket.
2. One of the wall switch wires may be grounded.
Remove wall switch wires from valve terminals if
pilot now stays lit, trace wall switch wiring for
ground. May be grounded to fireplace or gas
supply.
3. Check thermopile with millivolt meter. Take
reading at thermopile terminals of gas valve.
Should read 250-300 millivolts (minimum 150)
while holding valve knob depressed in pilot
position and wall switch "Off". Replace faulty
thermopile if reading is below specified minimum.
Check burner orifices for debris and remove.
Turn valve knob to "On", place wall switch to "On"
millivolt meter should read greater than 100 mV. If
the reading is okay and the burner does not come
on, replace the gas valve.
Clean and/or adjust pilot flame for maximum flame
impingement on thermopile and thermocouple.
Check the vent terminal for blockage (recycling the
flue gases)
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