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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22514
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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My name is ***** ***** and we have a criterion II gas

Customer Question

Customer: My name is ***** ***** and we have a criterion II gas furnace. flame kicks on a about 30-45 seconds later you can see the flame blowing back on itself and then goes out.
JA: Thanks. Can you give me any more details about your issue?
Customer: we reset the sensor then the furnace will run normally for just under a minute then it flashes and the flame turns back on itself and then goes out.
JA: OK got it. Last thing — JustAnswer charges a fee (generally around $18) to post your type of question to HVAC Experts (you only pay if satisfied). There are a couple customers ahead of you. Are you willing to wait a bit?
Customer: that depends if you know how to fix it without calling in a serviceperson
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Submitted: 1 year ago.
Category: HVAC
Expert:  BillyHvac replied 1 year ago.


My name is Billy.

I am afraid it is bad news. The flame is blowing back because you have a bad heat exchanger. This is like a car having a blown is the worst thing that can happen. The flame is blowing back because there is a hole or crack in the exchanger.

When the main blower kicks on it blows air through this crack and washes flame backwards.

I am very sorry for this news, but I wanted to be up front and not waste your time. You will need to call for service and will end up replacing exchanger ($900+) or replacing furnace.


Customer: replied 1 year ago.
OK didn't want to hear that thanks
Expert:  BillyHvac replied 1 year ago.

I understand..many here wont take bad news questions as they dont want a bad rating....but I believe in being upfront regardless..

I apologize for the news and wish you the best.