Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

weil-mclain ignition problem

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?


  • HVACNUTHVACNUT Member Posts: 3,274
    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.
  • JohnNYJohnNY Member Posts: 2,432
    Weil-McLain hot surface ignition? Is this an old GV boiler?
    For installations, troubleshooting, and private consulting services, find John "JohnNY" Cataneo here at :
    "72°F Mechanical, LLC"
    Or email John at [email protected]
    John is the Boilers and Hydronic Heating Systems Course Instructor at NYC's Mechanics Institute, a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
    John also oversees mechanical installations and maintenance for metro-area clients with his family's company, Gateway Plumbing and Heating along with his brother/business partner.
  • USAFVETUSAFVET 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.
  • USAFVETUSAFVET 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.
  • JUGHNEJUGHNE Member Posts: 6,793
    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?
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!