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Plumber Matthew
Plumber Matthew, Plumber
Category: Plumbing
Satisfied Customers: 154
Experience:  Licensed Journeyman Plumber. Eleven years of Commercial and Residential plumbing.
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We have a Weil-McLain Gas-Fired Boiler. I am trying to light

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We have a Weil-McLain Gas-Fired Boiler. I am trying to light the pilot. When I depress the gas cock dial in the pilot position...the pilot lights. I keep the dial depressed for several minutes, but when i release it and try to turn the knob to on the pilot goes out. I've tried (following the directions) several times, but every time as I release the knob, the pilot goes out. Any suggestions? Thanks
Hello and thank you for your question,

Without a little more information I would suggest that this is a classic case of a non working thermocouple. If you can provide me with the exact model boiler you have I will be able to confirm this diagnoses as well as help give you step by step instructions for repairing it.

I look forward to your reply.

Thanks and good luck!
Customer: replied 7 years ago.
I am not sure of the exact model. I can tell you that the instruction manual is for Type P-CG and CGM Gas-Fired Boilers (Series 7). You have suggested that it may be a non working thermocouple. Being that I don't know much about furnaces (other than turning it on and off), am I going to have to call someone to come and fix this? We are headed for 40 degree highs this week and I would like to get this taken care of before that. Have I sufficiently explained the problem? (The pilot stays lit only as long as the gas stop cock is DEPRESSED, while the knob is in the pilot position. As soon as the knob is released to try to turn it to ON, the pilot goes out.)

Thanks for your first response, I look forward to hearing from you again.
My deepest apologies for not responding sooner. What you describe sounds exactly like a non working thermocouple. Does your instruction manual mention anything about the thermocouple? You should be able to change the thermocouple yourself with basic hand tools. They are available at most home improvement centers.

Here is a website with manuals that pertain to your boiler:

And here are some basic instructions for replacing a thermocouple:

And finally here is a photo of an uninstalled thermocouple:

I hope you find this information helpful. If there is anything else I can do to assist you please let me know. Thanks and good luck!
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