Latest Discussions : HVAC

jasmine

06:52PM | 11/11/04
Member Since: 11/10/04
2 lifetime posts
My furnace has started to make a "thunking" noise AFTER it turns off (there is a long cycle, furnace stops, 30 seconds later a "thunk", then the fan goes on for a bit...then it all starts over with the next cycle). By the way this began after a technician came out and cleaned the furnace and did a "check-up" The owner of the company came out and said it was not the ductwork; but a "bad weld" in the heat exchanger. He did not take anything apart or off the unit.. said he could "hear it" in the unit. The furnace is approx. 25 years old and runs fine. He told me to get a CO alarm and to replace the furnace (sent me an estimate of course) Any ideas? Thanks, Jasmine

cellarwater

04:24PM | 11/14/04
Member Since: 12/09/03
175 lifetime posts
If you can take the panel off to expose the fan switch then turn on the fan without the burner. If it thunks, feel the duct work for a spot that may pop with the added air pressure. Also, the fan may be loose, or there may be a loose panel on the furnace. C.

jasmine

04:30PM | 11/14/04
Member Since: 11/10/04
2 lifetime posts
Thanks so much "C" for the ideas about my thunking noise. I'll get someone to try that...by the way..I've told a few people about the "estimate" he gave me for a new furnace and they were outraged...said it should cost half the amount he quoted; but probably there's something "loose" in there...NOT the heat exchanger. I appreciate you taking the time to post.... jasmine

cellarwater

07:19PM | 11/15/04
Member Since: 12/09/03
175 lifetime posts
I hopr that the "thunk" is a minor problem. I appreciate your getting more opinions on this. Contractors are like doctors always get more opinions. Good Luck. C.

mdunn177

04:33AM | 11/24/04
Member Since: 11/13/04
3 lifetime posts
My furnace also makes a thunking noise approx 10-15 minutes after it turns off. It almost sounds as if someone is hitting a piece of metal.

I'd be interested to know what you find out about your furnace. Maybe the same problem relates to mine.


Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.

Reply choose button

Anonymous

Post new button or Login button
Register