furnace question

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msnhockey
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furnace question

Post by msnhockey » Mon Jan 01, 2018 6:20 am

I have tried looking on google but no real answer that i could find.

Not sure if this is an issue or not.

My furnace blows heat, I do have a pilot light but that is the only flame I see when its running. The furnace also seems to be running quite a bit as well. Will run for about 10-12 mins then shut off for approx 4 mins, then start back up.

I don't see any flames on the burners, which I am sure is a concern?

Any insight is appreciated

Freon
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- furnace question

Post by Freon » Mon Jan 01, 2018 1:15 pm

I find it hard to believe your furnace "blows heat" with only a pilot light as the heat source. What is the make and model of the furnace? What are the outdoor temperatures today, Jan. 1? Does the furnace keep your house warm? What temperature is your thermostat set at?

msnhockey
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- furnace question

Post by msnhockey » Mon Jan 01, 2018 2:09 pm

So the burners are lighting up. They stay lit for approx 3 mins then goes out and the fan keeps running blowing warm air for approx 7 mins after the burners go out.

Furnace is a Lennox. Not sure on model but it must be 20 years old at least. Right now its about -13 C outside and thermostat is set at 20 C inside.

I think I was just at the furnace when it was only the fan on and everything is fine. I still think I should book a service as I been in the house for a year and I don't see any service date stickers on the furnace other than the duct cleaning one I had done when I moved in.

Freon
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- furnace question

Post by Freon » Thu Jan 04, 2018 2:38 pm

You wrote,"So the burners are lighting up. They stay lit for approx 3 mins then goes out and the fan keeps running blowing warm air for approx 7 mins after the burners go out."

That is a symptom of either a heat exchanger overheating (not enough air flow due to dirty filters, collapsed ducting or other restrictions) or you have a high limit switch that's not working properly. Easy start is to check all filter(s). If the furnace is relatively new I would not think that the high limit heat sensor is the problem but a technician could measure the temperature and tell you.

If you have an AC evaporator coil in the system, check that it is not clogged. Air flow is critical for the furnace to work correctly.

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