DIY Home Improvement Forum banner

Lennox furnace serial 6396j0178 model 80mfg3-75a-5

1187 Views 4 Replies 4 Participants Last post by  yuri
From what I can tell, I believe I need a new flame sensor. Everything starts up, but than when the flames kick on everything turns off.

Suggestions? Does this sound right?

1 - 5 of 5 Posts
A cleaning probably will buy time. Video: Clean with emery cloth, not sand paper.
already cleaned...

It's been cleaned twice. Yesterday, cleaned again. Worked for a couple hours and than started shutting down again.
The flame sensor is just a steel rod with a ceramic insulator. If the ceramic isn't cracked and the rod is clean than the problem is not the flame sensor. Rust on the end of the burners or a poor ground will also interfere with the control boards ability to sense flame being present.
espicially with that furnace. I have even had to run a green groundwire from one of the screws on the burner box directly to the circuit board ground to make them work better.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.