64
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
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 qualified service technician.
SYMPTOM
POSSIBLE CAUSES
CORRECTIVE ACTION
1.
Spark igniter will not
light pilot after repeated
triggering of igniter but-
ton.
A.
Defective igniter
(no spark at electrode).
Check for spark at electrode and pilot; if no spark and electrode wire is
properly connected, replace igniter.
B.
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 – should be 1/8" to have a
strong spark. If gap measures 1/8", replace pilot
(Figure 86 on Page 56)
.
C.
Gas supply pressure errant.
Check inlet gas pressure. It should be within the limits as marked on
the rating plate.
D.
Pilot orifice plugged.
Clean or replace pilot orifice.
2.
Pilot will not stay lit
after carefully following
the lighting instructions.
A.
Defective pilot generator
(thermocouple).
Check pilot flame, it must impinge on thermocouple
(Figure 86 on
Page 56),
clean and/or adjust pilot for maximum flame impingement
on thermocouple. Ensure that the connection between the valve and
thermocouple are tight and secure.
3.
Pilot burning, no gas
to burner, Valve knob
“ON,” Wall Switch “ON.”
A.
Wall switch or wires defective.
Check wall switch and wires for proper connections. Jumper wire
across 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.
B.
Thermopile may not be generating
sufficient millivoltage.
Check thermopile with millivolt meter. Take reading at thermopile terminals
of gas valve. Should read 325 millivolts minimum with optional wall switch
“OFF.” Replace faulty thermopile if reading is below specified minimum.
C.
Plugged burner orifice.
Check burner orifice for stoppage and remove.
4.
Frequent pilot/burner
outage problem.
A.
Pilot flame may be too low or blowing
(high) causing the pilot/valve safety to
drop out.
Clean and/or adjust pilot flame for maximum flame impingement on
thermocouple
(Figure 86 on Page 56)
.
Installation and Operation Instructions
900300-00, 01/2018
Innovative Hearth Products
DRT35ST and DRT35PF Direct-Vent Gas Fireplaces
