Weil Mclain boiler won't fire:

bushleagueMarch 7, 2009

Okay my circa 1990 Weil Mclain HE-4 gas boiler refuses to fire. I changed the hot surface ignitor a month ago with no problem and it has been firing fine until today. The ignitor glows and you can hear the relays for the firing sequence, then one more click and the ignitor shuts down. The blower runs fine, and the vacuum appears correct, the gas is on at the meter (I have no other gas appliances). Any ideas here? Oh and the HE-4 does have the flame sensor mod and the ignitor is angled down app 15 degrees toward the gas tubes. Thanks!

Thank you for reporting this comment. Undo
mr_havac

Do you have 24 volts at the gas valve terminals after pre purge?

    Bookmark   March 7, 2009 at 8:53PM
Thank you for reporting this comment. Undo
bushleague

mr hvac I wasn't getting 24 volts anywhere leading me to believe that the transformer had failed. I reseated all of the terminals on the brain box (white-rogers) then gave it a few taps with my screwdriver handle and it fired. After about two minutes the flame went out, and with the blower still running, fired again. The boiler has always done this, especially when calling for heat. Conversely I have an HE-3 in an income property that pedals like crazy without stopping until the thermostat is satisfied. I would imagine this is a function of the controls, specifically the brain box and not the boiler itself. I did find similar related complaints on a diy forum, and reference to a Weil Mclain brand updated controller.

    Bookmark   March 8, 2009 at 9:29AM
Sign Up to comment
More Discussions
Thoughts on proposed HVAC system?
To start: my house is two-level (main plus upper)...
gbleeker
Heat Pump.....will it really save me money?
I recently moves into a new house in Mass, a 1650 sq...
Jinx_1832
gas wont come on. forced air gas fired furnance
the Furnace was starting then running a couple minutes...
waterguytexas
Are mini-splits a bad idea.
I have lived in both Europe and the Middle East and...
bry911
Opinions please Mitsubishi M - S E R I E S H I G H P E R F O R M A N C
Our HVAC guy is suggesting this for a complete system...
almostemptynester
Sponsored Products
Eagle One Recycled Plastic Alexandria Patio Chair - C361BLK
$314.00 | Hayneedle
Tonal Silver And Bronze Mirrored Dresser
Zuri Furniture
Grand Prix Chair - Wood Legs by Fritz Hansen
$719.00 | Lumens
Light Brown 18 x 18-Inch Pillow with Hidden Zipper
$42.00 | Bellacor
Modern Indoor/Outdoor Area Rug: Well Woven Rugs Barclay Terrazzo Ivory 5 ft. 3
Home Depot
Bacara Tahari Chocolate and Beige Rectangular: 5 Ft. 3 In. x 7 Ft. 6 In. Rug
$214.00 | Bellacor
Vigo Bathroom Glass Vessel Sink in Blazing Fire and Dior Faucet Set in Antique
Home Depot
Rizzy Home Detailed Peacock Wing Decorative Throw Pillow - T04921
$22.00 | Hayneedle
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™