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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 8511
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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No LED's lit on 63k8901 control board G26 model C23-41-1

Customer Question

No LED's lit on 63k8901 control board for Lennox G26 model C23-41-1 furnace.
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

Look close at igniter and see if maybe there is a burned spot or crack, It should be ohming between 50 and 90.

See video

Customer: replied 1 year ago.
Trouble shooting doc from says range is10.9 to19.7 ohms on page 43 of attached PDF. I'll take it out and look at it but it does fall within that range. Can there be that much difference between igniters?
Expert:  airheatman replied 1 year ago.

You are correct.That is what the manual says. That sure seems low for an igniter, but looks like according to Lennox specs, it is within range.Silly question, but this new board is the recommended replacement right?

Expert:  airheatman replied 1 year ago.

I am wondering if maybe you have to replace Lennox' low ohm igniter when using this board.I did find this in the installation manual for the board

Customer: replied 1 year ago.
According to this page,, the original dead board 63k8901, and the replacement, 97L4801, can be replaced by 83M00. This would seem to indicate interchangeability between the first two. I took the igniter out and it is a straight tang made up of two tangs sandwiched together. There is some discoloration but no burnt spots that would indicate a short or open.
When you say "installation manual for this board," are you referring to the 97L4801 that I installed and is faulting as I explained? If so, then I guess the way to go now is to find the right igniter. Do you have a part number that I can shop with?
Customer: replied 1 year ago.
This is the igniter I have:
Expert:  airheatman replied 1 year ago.

That appears to be the silicone igniter, Perhaps doa board.I am going to open this to other experts who may have other suggestions.

Customer: replied 1 year ago.
Don't think igniter is problem. Old board, replacement board and newer replacement board all use existing igniter. I ran a ground wire from board directly to utility ground and results are the same. The only thing that I have a question about now is about the 24vdc transformer. It is putting out nearly 28vdc. Could that amount affect the board operation? I see this all the time at work with no problems. I am going to order a new upgraded board--either 83M00 - Lennox or Emerson 21D83M-843.
Expert:  Phil replied 1 year ago.

Hello, those transformers are rated at 24 volts AC... 28 volts ac well in range, it varies with the primary voltage, 208 to 240 volts and voltage fluctuations on the utility grid.

That variable will not affect your situation, the incorrect board or igniter will of course.. stay in touch as needed.

Customer: replied 1 year ago.
I meant vac not vdc. I will let you know how new board works.
Expert:  Phil replied 1 year ago.

I will be here, good luck with it.