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gotoman for ac
gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 5178
Experience:  51 years of experience install design and repair of all makes and models of AC
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I have a Lennox L.P. Furmace, ser. # 5881GO3611, mod #

Customer Question

I have a Lennox L.P. Furmace, ser. # 5881GO3611, mod # G1203-110-3, input 110,000 btu, mfg. Marshalltown, Ia., unit i.d.# G 12Q-3110-3
occationally when the unit lites it does so with a fairly loud report-boom and then usually burns normally and heats good. If when it goes boom and you have the door off and able to watch it there is about a 2 foot fireball then burns normally. Ocassionally after the boom when it lites 1or 2 of the burners will have a flame near the orifice. It can be corrected by blowing on it or something similar. The pressure is 10.5 inches of water column and the adjustment screw will not budge.
The burners and unit have been cleaned, checked etc. by two professionals and myself..Neither of the two experienced people had a solution. It does a good job of keeping the house warm, just an occasional boom.
I have had training on portable space heaters, Propane, kerosene, diesel, etc. and do have a fair amount of experience.
What do you think? I don't want a phone call tonight so as not to disturb my wife. Anyhow that's it.
Submitted: 7 months ago.
Category: HVAC
Expert:  gotoman for ac replied 7 months ago.

Russ here. If cleaning burners does not work. You will need to replace them. I have had problems like this on propane furnace and cleaned burners and still had same problem. Replaced burners and problem went away. The factory rep would give same advice. If you need source please let me know. Russ

Customer: replied 7 months ago.
That sounds like the most promising idea I've received. How does that change what is happening in the unit. Just curious!
Customer: replied 7 months ago.
I will give it a try! Thanks!
Expert:  gotoman for ac replied 7 months ago.

You are welcome. If you need parts go to That is a Lennox site. If no more questions please rate answer. Russ