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weil-mclain ignition problem

USAFVET Member Posts: 3
Checking the boiler WM HE for the season as usual. Called for heat, draft fan comes on, the hot surface igniter glows after prescribed delay gas valve clicks but does not open for main burner ignition. I tried several times, different mechanical sounds. Put a meter on valve wiring, when gas valve clicks I read voltage which immediately goes away. Gas valve or ignition control?


    HVACNUT Member Posts: 5,890
    Is the gas valve on?
    Does yours have the Honeywell control module? Is it showing a code?
    You say theres voltage at the gas valve, but what is that voltage. Trial for ignition only takes a couple seconds so if theres no flame rectification then voltage drops out for the gas valve.
  • JohnNY
    JohnNY Member Posts: 3,244
    Weil-McLain hot surface ignition? Is this an old GV boiler?
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Consulting & Troubleshooting
    Heating in NYC or NJ.
    USAFVET Member Posts: 3
    The control module is Fenwal, there are no codes. Happens very quickly, the valve does not have the normal mechanical sound when it's working correctly.
    USAFVET Member Posts: 3
    Just reinstalled the ignition control, fired up, perfect several times. Must have been a dirty contact on the harness plug of a ground wire.
    JUGHNE Member Posts: 11,109
    Re-seating push on terminals has fixed a lot of problems.
    Off and back on cuts thru any oxidation of contact points.
    The same applies on the burner end. Does this have a separate flame sensor?