# Lennox Elite Series Furnace Problem



## steges (Jan 24, 2010)

I have a Lennox Elite Series furnace that is giving me an error code according to the diagram on the front. The left green light is slow flashing and the right green light is solid which according to the diagram means the primary/seconday limit switch is open. The furnace will run for a while after I turn the power to the furnace off and back on but then when the thermostat calls for the heat to kick on a second time the furnace will not ignite again withouy cycling the power once again. 

I was having this same problem a few weeks ago and went to a much cheaper grade filter and the problem went away. I also cleaned the sensor in front of the flame with some light grit sand paper but the problem is now back.

Does anyone have any suggestions?

Thanks


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## SKIP4661 (Dec 3, 2008)

If you have an a/c evaporator you will want to check both sides to make sure it is not plugged with dust and debris. Also make sure all registers and grills are unobstructed and open.:thumbsup:


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## Tator1076 (Dec 22, 2009)

You need to check Fan limit switch. It maybe bad I had replace some on that unit.


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## hvac benny (Dec 29, 2009)

When you cleaned the flame sensor a few weeks ago you probably put small grooves in it that will trap the dirt and not be able to be cleaned out. Never use sand paper, use fine steel wool or even a dollar bill.


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## steges (Jan 24, 2010)

*Problem still a mystery*

Thanks for all of the feed back. The one thing I did do to just test was to pull the furnace filter out and the furnace ran all day and night without a problem. I have used the same furnace filter for 9 years now until I just changed to a cheaper less dense filter when I first started having this problem. As stated earlier once I changed to the cheaper filter the problem went away for a few weeks and then came back again yesterday and is now gone when I pulled the furnace filter out.

Could the flame sensor be going bad? The whole reason I changed filters was b/c we had a cold snap and the furnace was running more than normal and I was told that with a dense filter it is not allowing the heat exchanger(I believe that is what I was told) to cool down properly.

Does this make sense? Am I on the right track or was I given miss information?


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## Marty S. (Oct 31, 2009)

Check the blower motor capacitor. They get weak over time and need to be replaced. Most new ones have a rating +/- 6% so it doesn't take much loss to have a low mfd capacitor out of specs.
Too restrictive of a filter is hard on motors and heat exchangers.


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## pruibb (Nov 6, 2010)

lennox furnace g26 flame will not lite


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## yuri (Nov 29, 2008)

Any error codes from the flashing led lights in the viewing window on the lower door? Does the exhaust ventor fan inside the unit behind top door run when you turn it on and turn up the thermostat?


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