TROUBLESHOOTING THE MILLIVOLT GAS CONTROL SYSTEM

Note: Before troubleshooting, make sure that the appliance main line gas shut-off valve and the gas control valve are in the "OPEN" position and the burner ON/OFF switch 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 ignitor will not lightA. Defective ignitorCheck for spark at electrode and pilot; if no spark and

 

pilot after repeated(no spark at electrode).electrode wire is properly connected, replace ignitor.

 

triggering of ignitor button.

 

 

 

 

 

B. Defective or misaligned electrode

Using a match, light pilot. If pilot lights, turn off pilot and

 

 

 

 

 

 

at pilot (spark at electrode).

trigger the ignitor 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 9 on page 7).

 

 

 

 

 

 

 

 

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 afterA. Defective pilot generator

Check pilot flame, it must impinge on thermocouple (Figure

 

carefully following the(thermocouple).

9 on page 7) Clean and/or adjust pilot for maximum flame

 

lighting instructions.

 

impingement on thermocouple. Ensure that the connection

 

 

 

 

between the valve and thermocouple are tight and secure.

 

 

 

 

3.

Pilot burning, no gas toA. Wall switch or wires defective.

Check wall switch and wires for proper connections. Jumper

 

burner, Valve knob “ON,”

 

wire across terminals at wall switch, if burner comes on,

 

Wall Switch “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

Check thermopile with millivolt meter. Take reading at thermo-

 

 

 

sufficient millivoltage.

pile terminals of gas valve. Should read 325 millivolts mini-

 

 

 

 

mum with optional wall switch “OFF.” Replace faulty thermo-

 

 

 

 

pile if reading is below specified minimum.

 

 

 

 

 

 

 

 

C. Plugged burner orifice.Check burner orifice for stoppage and remove.

 

 

 

 

 

 

 

 

4.

Frequent pilot/burner outage

A. Pilot flame may be too low or

Clean and/or adjust pilot flame for maximum flame impinge-

 

problem.blowing (high) causing the pilot/ment on thermocouple (Figure 9 on page 7).

 

 

 

valve safety to drop out.

 

 

 

 

 

 

20