I noticed my furnace occasionally making a whoosh sound and the burner flames pop out of the burner chamber (but still inside the unit). My friend, an HVAC guy says that the heat exchanger is bad and it is sucking air into the system. He said that I need a new furnace. It still runs fine, but this sound and occasional flame are obviously worrisome. The unit is clean and there is no major debris inside. It's in a small apartment and I don't run it continuously, and it's original to the unit (24 years). Any way to avoid a major replacement by fixing?
First of all buy a carbon monoxide detector. That will cover you if combustion gases are making their way through the exchanger. Your friend could be right but it sounds like only an assumtion. Try cleaning (while off) with a wire brush. after you have scrubbed it real good and inspected for rusty holes in the combustion chamber, vaccum it out real good with a shop vac (each chamber). If that doen't work and flames are still rolling out....call a technician. A new heat exchanger can be an exspensive change-out, try what I said first and go from there. Good luck!
If it's 24 years old, you could get a much cheaper running unit, and save money. I replaced mine a couple of years ago and I've figured it will pay me back in another couple of years with fuel savings.
Remove the burners and open the holes up with a wire brush. They get rusty.
While your heat exchanger may be bad....you should have another opinion (just like the doctor). You may be having a small amount of carbon build up on the injector which can cause the whoosh sound. You didn't mention if you are using gas or oil. 24 years is a long time and you really should get someone to look at it just for the peace of mind. Preferably not a friend! Yes, he probably knows his stuff but this is one of the times you get an outside opinion. If the opinion is the same, then you need to decide on the replacing.
If the heat exchanger was bad (cracked) it wouldn't cause this problem. What it is called is flame roll out and on a unit that old is probably due to dirty/rusty burners or a weak pilot flame. Call another heating company and ask them how much to clean the burner assy. It should be $200 or less.
