My shop furnace quit. I cant call a service tech because my dumbass thought to pull the spark plug and check it, it took the most of the threads with it. I can jb-weld it back in to make sure it seals but think a service guy will condemn it or something.

Maybe someone knows about these things

It is a lennox G14

I am getting gas through the valve

It is getting to the plug

the plug is sparking

I pulled the flame sensor and cleaned it

the intake blower is working

No ignition, any furnace guys out there?

Thanks for any insight!!!

air pocket maybe? youve got all three ingrediants for fire so it should work right?

I can jb-weld it back in to make sure it seals but think a service guy will condemn it or something.


Heli-coil instead?

I'd heli coil it, however there is a good chance that the secondary heat exchanger is leaking, that's reason to condemn. Lennox pulse furnaces had a problem with the secondary heat exchangers, most techs will want to do a pressure test, if it fails it could be unsafe, there is the possibility that carbon monoxide could be leaking.

Was this furnace originally installed in your shop or is it just one pulled from a house and recycled?

Brewchief:D

It was an original install, I think we can repair the plug and get another year out of it if I can fix this.

If the heat exchanger is bad( and there is a good chance it is) it may still be under warranty, warranty was lifetime to original owner, 20 years if owners change. Since heat exchangers aren't available lennox will give you a replacement furnace for free, you pay for install. If you post s/n I can tell how old it is.

Brewchief:D

If you have a draft inducing fan motor and a condensate tube draining from it, Check to make sure it's not plugged as this will sometimes cause backpressure in the venting system and not allow the vent pressure switch (connected to the draft motor by a small tube) to operate. Good luck, Dave