# Ignition module buzzing



## yuri (Nov 29, 2008)

Post the brand name and model # of furnace. Also the name of the module. Pics of the furnace with both doors off will help also. Need 5 posts B4 you can do that. Go to the home page and introduce yourself and get to 5 posts.


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## Wiatt (Nov 17, 2014)

Ok will do.


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## Wiatt (Nov 17, 2014)

Furnace is a Lennox. M# g20q2e-50-2

Original ignition module was robertshaw m# sp735l part# 18g9101
Replaced ignition module with part 97h0401

I'll have to post pics in a couple hours.


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## yuri (Nov 29, 2008)

I guessed it was . That is normal. The new module is a Honeywell and sounds a lot different. It keeps the spark on for 20 seconds to make sure the flame is established and makes a loud pulsing buzzing sound.


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## Wiatt (Nov 17, 2014)

The buzzing noise is definitely coming from the ignition module though. Not the sound of a spark from the ignition.


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## yuri (Nov 29, 2008)

Cannot say w/o being there myself. Occasionally modules do buzz. Check to see if you have a steady 24 volts to it. Have not had one buzz other than the pulsing spark sound. Is it securely mounted to the plate.

Whisperheats are a dying breed and have lots of pieces to cause trouble. I would invest in a new furnace soon. I am a Lennox dealer and know that unit well.


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## Wiatt (Nov 17, 2014)

Almost sounds like something chattering back and forth at a high speed with in the ignitions mod. I have tried mounting it in different orientations. The back plate is secure. And the unit to the back plate. I can borrow a multi meter. Should I be testing the piolet valve while its starting up ? Not sure how to check if it's getting a clean 24v. 

Ultimately I was worried I had a defective ignition box. 

I know it's on its last leg. I thought I could get it to limp through and last xmas


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## yuri (Nov 29, 2008)

I know that unit intimately and love to hate it. Actually it is a good unit and was a very clever idea Lennox had as it is totally quiet unlike any other mid efficiency furnace with a exhaust fan. There has been some problems with that Honeywell gas valve ( can happen to other brands too ) where it develops a short between the PV and MV/pilot valve and main valve. Can be dangerous as it energises the main valve and pilot valve and spark at the same time and goes BOOM on startup. Can happen to any valve or brand. I suspect you have a short in the valve or BCC fan timer board which is agravating the ignition module. Difficult to troubleshoot w/o parts changing. Now you see where it is going to be a $$ repair pit. Like I said it is not a Lennox fault, just the way that electronics fail from age.


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## Wiatt (Nov 17, 2014)

Stupid thing keeps buzzing the whole time now.


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## Wiatt (Nov 17, 2014)

not sure if we are aloud to post links. I made a video of what its doing and put it up on youtube

https://www.youtube.com/watch?v=hAtSs9WUgfQ&feature=youtu.be


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## Wiatt (Nov 17, 2014)

http://imgur.com/SPDKDJK
http://imgur.com/AFFWUuv
http://imgur.com/Hyp2WUL

3 pics of the stupid furnace

I volt tested PV and MV both 24-26v
Im not sure what else to start volt testing


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## yuri (Nov 29, 2008)

Where did you get that control from. Looks USED to me. Has a date code of 9645 which means 1996 45th week. If you got it from ZBay it looks used.

The new replacement is a black Honeywell S86U type control. Also you do not have the Honeywell valve I was talking about.

I think you got a used part but I could be wrong.

If you want a proper control try Cozyparts.com for genuine Lennox parts.


http://www.cozyparts.com/


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## Wiatt (Nov 17, 2014)

It came from a stupid local hvac supply wholesaler. Should I try to return it? It came in a new box. Dusty but new =( does cozyparts have a Canadian version


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## yuri (Nov 29, 2008)

Its CRAP and used or been sitting around since 1996 and dead anyway IMO. Take it back and order the proper one from Cozyparts. They are VERY reputable.


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## yuri (Nov 29, 2008)

I don't think Cozyparts have a Cdn division and may not ship to Canada. Try them as they may have changed that policy.

Otherwise google: "Lennox furnace parts Canada". as there are others I saw a year ago.


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## Wiatt (Nov 17, 2014)

just wanted to come back and say thanks yuri. took old module back and he gave me a new one, same model and part though. But at least its working. Gas valve is making 2 solid clicks. seems normal though. no buzzing. hope i can get through this winter as is.


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## yuri (Nov 29, 2008)

There are 2 clicks: 1 for the pilot valve and aother for the main valve. Look at the date code. That part has been superseded by a Honeywell one a long time ago. If it lasts the Winter great. I would get a new furnace as there is another circuit board which turns on the fan which can die soon. Not worth spending a lot of $$ on.


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