Our furnace makes a loud bang right as it is turning on. Now I have heard furnace noises before, but this one is really loud. Like someone bangs on the duct work. Any ideas of how we can stop this? It is so loud it wakes a couple of the light sleepers in the family at night. Thanks for any help!

Chey

 

You didn't give us much to go on, but if it is a warm air furnace, it might be air pressure or heat causing something to flex. Like a plenum on the furnace or a larger piece of trunk duct. You really have to be there when it does it and track the noise to an area. Then you can begin to resolve the problem. It is a relatively easy fix once you locate the offending part.

Ken

 

does it do it in cooling? if not, i would look at the ignition, it could e delayed by dirty burners, or other causes. watch the furnace when it lights and tell us what happens..

 

Thanks for your responses. Sorry for the lack of info. I really don't know that much about these things. But I can tell you that it didn't do it when we used the central air. But the unit for that is outside. I know it uses the same ducts so I am assuming that's why you asked about it.

Not sure what you mean by is it a warm air furnace. I thought they all were. I guess it is since it puts out warm air. Now don't laugh, I really am ignorant of these things.

My husband has MS and can't do things around the house much anymore, that's why I must take care of it. Not really sure if he would mess with it anyway since a couple of years ago, at our old house, there was something wrong and when he went to light the pilot that went out it blew in his face. Spent time in U of Chicago Burn unit. But he's fine now. Sorry for the ramble and thanks again for the help!

Now off to see if I can hear exactly where this bang is coming from!

Chey

 

stand back as the furnace ignites and watch and listen. it does not appear to be a ductwork issue, delayed ignition is still on my mind. thank your son for what he is doing for the safety of my children.

 

Sorry for the OT. Don't want to upset anyone, but wanted to respond to hvac4u

No furnace update yet, just had to thank you for the goose bumps this morning. I will relay the message to my son. We are very proud of him for what he is doing. Just can't wait for him to be home though.

Chey

 

Well, the bang is coming from approx 10 feet away from the furnace, so I am assuming this isn't an ignitor problem? I am going to try to spend sometime cleaning the basement in the next couple of days to pinpoint the area where the bang is coming from. Thanks for everyones help so far!

Chey