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NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
19
TROUBLESHOOTING THE MILLIVOLT GAS CONTROL SYSTEM
Note: Before troubleshooting the gas control system, be sure external gas shut off valve (located at gas supply inlet) is in the
“ON” position. Important: Valve system troubleshooting should only be accomplished by a qualifi ed service technician.
SYMPTOM POSSIBLE CAUSES CORRECTIVE ACTION
1) Spark igniter will not light
pilot after repeated triggering of
igniter button.
WARNING: IF THE PILOT WILL
NOT LIGHT AFTER ONE MINUTE
OF ATTEMPTING, WAIT FOR AT
LEAST FIVE MINUTES FOR GAS
TO CLEAR BEFORE ATTEMPT-
ING AGAIN.
A. Electrode wire (at piezo igniter) not pushed completely
on.
• Check connection
B. Piezo igniter is defective
• Replace piezo igniter
C. Defective or misaligned electrode at pilot (spark at
electrode)
• Using a match, light pilot. If pilot lights, turn off pilot and trigger the igniter
button again. If pilot lights, an improper gas mixture caused the bad lighting
and a longer purge period is recommended. If pilot will not light – check gap at
electrode and pilot – It should be between 1/8” and 3/16.” If the gap is out of this
range, adjust the gap or replace the pilot assembly. See Page 11, Figure 25.
D. Incorrect lighting procedure • Carefully follow the lighting instructions on Pages 15 &16 or as found in the
insert control compartment.
E. Gas supply problem
• Check for multiple gas shut-offs. Check gas supply lines. Check inlet gas
pressure. It should be within the limits as marked on the rating plate.
F. Pilot orifi ce plugged
• Clean or replace pilot orifi ce
2) Pilot will not stay lit after
carefully following the lighting
instructions.
A. Thermocouple is not fi rmly connected to control valve
• Check connection at valve
B. Pilot fl ame is not directed to top of thermocouple
• Ensure thermocouple is fully inserted into pilot assembly. Clean and/or adjust
pilot for maximum fl ame impingement on thermocouple if necessary.
C. Thermocouple is defective. The millivolt production
should be a minimum of 14 MV with pilot only.
• Replace thermocouple
3) Pilot fl ame stays lit, but
main burner will not light
(valve pilot/off/on knob is in
ON position, off/on switch, wall
thermostat or remote control is
set to ON).
Read important note below.
IMPORTANT NOTE: If an
optional Remote Switch*
is used for burner opera-
tion and if the standard
burner OFF/ON switch is
still installed on appli-
ance, it must be in the
"OFF" position.
A. Burner control switch (off/on switch, wall thermostat
or remote control) is in “OFF” position; or thermostat (if
installed) is set to a temperature setting that is too low.
• Turn burner off/on switch on and/or refer to instructions provided with optional
thermostat or remote control, if applicable.
B. Electrical wiring is damaged or poorly connected or
remote switch is defective.
• Check wall switch and wires for proper connections. Refer to Millivolt Wiring
Diagram (Page 12, Figure 28). Jump the wire across terminals at the wall switch,
if the burner comes on, replace the defective wall switch. If okay, jumper the
wires across the wall switch wires at the valve. If the burner comes on, wires
are faulty or connections are bad.
C. One of the following components may be defective:
burner control switch, thermostat, vent spill switch, or
thermopile. Thermopile: Millivolt production should be a
minimum of 325 MV with pilot only.
• Refer to Millivolt Wiring Diagram (Page 12, Figure 28). Electrically bypass
components one at a time and replace defective item.
D. Thermopile may not be generating suffi cient mil-
livolts
• Check thermopile with millivolt meter. Take reading at thermopile terminals
of gas valve. It should read 325 millivolts minimum with optional wall switch
“OFF.” Replace faulty thermopile if reading is below specifi ed minimum.
E. Plugged burner orifi ce
• Check burner orifi ce for blockage and remove.
F. OFF/ON Switch & Remote Switch* are in the "ON"
position resulting in excessive resistance
• When turning on the burner using a Remote Switch,* ensure that the
standard OFF/ON Switch is in the "OFF" position. If both switches are in
the ON position, it may result in excessive resistance (& millivolt drainage)
and the burner may not come on.
4) Frequent pilot/burner outage
problem
A. Pilot fl ame may be too low or blowing (high) causing
the pilot/valve safety to drop out.
• Clean and/or adjust pilot fl ame for maximum fl ame impingement on thermo-
couple. See Page 11, Figure 25.
5) Main burner stays lit for up
to 10 minutes and then shuts off,
pilot fl ame remains lit.
A. Vent is blocked; fl ue gas is “spilling,” which activates
the spill switch and shuts down the burner.
• Examine venting system for blockage. Remove any blockage.
B. The house is negatively pressurized resulting in spill
switch activation.
• Open a window to see if the problem is corrected.
6) Smell of gas A. Pilot, gas supply system, or pilot & burner adjustment
screws on valve may be leaking. FOLLOW INSTRUCTIONS
ON THE COVER OF THIS MANUAL
• WARNING: NEVER USE AN OPEN FLAME TO CHECK FOR LEAKS.
After the gas company or fi re department has given clearance to re-enter the
dwelling, have a qualifi ed technician test all gas joints from the gas meter to
the gas heater regulator for leaks using a gas leak test solution (also referred
to as bubble leak solution).
7) A thin coating of black soot
forms on the window.
Note: See Page 5, Glass Clean-
ing.
A. Burner primary air inlet is restricted or blocked
• Ensure all openings (fresh air inlets) in the insert are free from dust and debris.
Recheck these areas periodically.
B. Flames make contact with logs or other surfaces
• Ensure ceramic logs are in their correct positions.
C. Improper venting
• Check for fl ue blockage, disconnected fl ue, improper installation. Make
appropriate corrections.
8) A white coating forms on
windows, logs, and/or inside walls
of fi rebox.
A. Residues/impurities being burned off or impurities in
the fuel
• Follow cleaning guidelines outlined in the MAINTENANCE section of this
manual.
*Optional Remote Switch kits: wall switch, wall thermostat or remote control.