old wall furnace makes banging noise

KarlJay · 12-14-2010, 01:13 AM

I'm moving my old wall furnace, it's fully disconnected and I want to fix the banging noise that it's made for the last 15 years I've had this house.

The house is over 70 years old and I don't have a clue as to the age of the furnace, I know it's at least 30 years old.

The furnace works fine, but when it cycles off, it makes a series of banging noises as it cools down. I don't want to replace it with a new one at this point.
Is this a common problem with old wall furnaces?
My guess would be the metal above the flame where the heat transfers is too close to a mount and the expantion/contraction of the metal is where the banging happens.
Any input / hints would be great...
Thanks, KarlJay.
I have a TIG welder and pretty extensive set of tools for metal working, so I don't mind making something that'll fix this.

hvaclover · 12-14-2010, 03:17 AM

That could very well be a cracked heat exchanger.

Wall furnaces are dirt cheap. Why not just buy a new one since you are moving it?

You have nothing to lose except high fuel bills.

userCA · 03-17-2011, 01:56 AM

I have the exact same problem with a wall furnace and am trying to figure out how to fix it. My landlord wants to replace the vent pipe, because he thinks the pipe is expanding/contracting and making the banging noise. But now I'm thinking it may be a problem with the wall furnace heat exchanger itself.

What did you find out about yours? Was it a cracked heat exchanger that was making the banging? If not, how did you fix it?

Thanks!

hvaclover · 03-17-2011, 02:18 AM

Quote:

Originally Posted by userCA

I have the exact same problem with a wall furnace and am trying to figure out how to fix it. My landlord wants to replace the vent pipe, because he thinks the pipe is expanding/contracting and making the banging noise. But now I'm thinking it may be a problem with the wall furnace heat exchanger itself.

What did you find out about yours? Was it a cracked heat exchanger that was making the banging? If not, how did you fix it?

Thanks!

If you suspect a crack I would call the land lord and demand a monoxide detector for the home. In every state in rental property they are required by law.

KarlJay · 03-22-2011, 08:34 PM

Update: I haven't addressed this issue yet, might just buy a new replacement. As far as your's having a crack, I'd go get a CO detector TODAY.
I got scared and bought one last year, everything is fine as far as CO goes.
The concern is that CO doesn't have an oder, so you can't tell if you have a leak.
Mine went off once when I had an old muscle car idleing in the driveway with the front door open. Couldn't tell anything except for the CO alarm going off.
It can KILL you...

unicursalhex · 03-23-2011, 12:21 AM

Yeah the detector is a good idea. I did a furnace maintenance a little while ago and found a big gaper right behind the heat exchanger limit. I shut the valve off and informed the old guy who owns the place that carbon monoxide is spilling into his house and that he needs to replace the unit. Before I could get my tools loaded he was turning the valve back on and running the furnace... Just did a follow up call today and he said he's going to replace it but he has some other things that are more pressing. Wow, whats more pressing than carbon monoxide poisoning? He's an old guy so he's set in his ways, hopefully that crack doesn't open up even bigger and give him the dirt nap...

seatonheating · 03-23-2011, 03:06 AM

Quote:

Originally Posted by unicursalhex

Yeah the detector is a good idea. I did a furnace maintenance a little while ago and found a big gaper right behind the heat exchanger limit. I shut the valve off and informed the old guy who owns the place that carbon monoxide is spilling into his house and that he needs to replace the unit. Before I could get my tools loaded he was turning the valve back on and running the furnace... Just did a follow up call today and he said he's going to replace it but he has some other things that are more pressing. Wow, whats more pressing than carbon monoxide poisoning? He's an old guy so he's set in his ways, hopefully that crack doesn't open up even bigger and give him the dirt nap...

Risking your life is more important than a couple thousand bucks....DUH!!

KarlJay · 03-23-2011, 05:05 PM

You might concider calling the City about that, we have people around here that DIE from time to time trying to heat their house with a BBQ and other things.
I didn't know the danger myself once. Problem with death... it's final...

Marty S. · 03-23-2011, 09:28 PM

Quote:

Originally Posted by unicursalhex

Yeah the detector is a good idea. I did a furnace maintenance a little while ago and found a big gaper right behind the heat exchanger limit. I shut the valve off and informed the old guy who owns the place that carbon monoxide is spilling into his house and that he needs to replace the unit. Before I could get my tools loaded he was turning the valve back on and running the furnace... Just did a follow up call today and he said he's going to replace it but he has some other things that are more pressing. Wow, whats more pressing than carbon monoxide poisoning? He's an old guy so he's set in his ways, hopefully that crack doesn't open up even bigger and give him the dirt nap...

Time to call the gas company so they can lock out his meter. Remember that CO damages all the internal organs including the brain. His reasoning ability might not be as good as it should be.

1mastertech · 03-24-2011, 02:49 AM

Quote:

Originally Posted by unicursalhex

Yeah the detector is a good idea. I did a furnace maintenance a little while ago and found a big gaper right behind the heat exchanger limit. I shut the valve off and informed the old guy who owns the place that carbon monoxide is spilling into his house and that he needs to replace the unit. Before I could get my tools loaded he was turning the valve back on and running the furnace... Just did a follow up call today and he said he's going to replace it but he has some other things that are more pressing. Wow, whats more pressing than carbon monoxide poisoning? He's an old guy so he's set in his ways, hopefully that crack doesn't open up even bigger and give him the dirt nap...

wow THATS INSANE!.You know as a professional in this trade we have the obligation to prevent people from harming and possibly killing themselves due to defective or damaged equipment.I would have disabled that furnace and made sure the ole boy couldnt relight the damn thing! thats sad because he probably doesnt have the money to repair it and needs it on.Some states have programs for the elderly that will actually replace at no cost a system that can kill the tenent or owner.I wouldnt have left that furnace to where it was operational at all>do you have any emergency assistance programs that do help the seniors in your area!

hvaclover · 03-24-2011, 03:10 AM

Quote:

Originally Posted by 1mastertech

wow THATS INSANE!.You know as a professional in this trade we have the obligation to prevent people from harming and possibly killing themselves due to defective or damaged equipment.I would have disabled that furnace and made sure the ole boy couldnt relight the damn thing! thats sad because he probably doesnt have the money to repair it and needs it on.Some states have programs for the elderly that will actually replace at no cost a system that can kill the tenent or owner.I wouldnt have left that furnace to where it was operational at all>do you have any emergency assistance programs that do help the seniors in your area!

your sense of duty is commendable but in the end only the customer will have the right to close down a furnace.

our city won't enforce a shut off. its all about liability.
t

1mastertech · 03-24-2011, 08:48 PM

Quote:

Originally Posted by hvaclover

your sense of duty is commendable but in the end only the customer will have the right to close down a furnace.

our city won't enforce a shut off. its all about liability.
t

Is That right? wow thats crazy,the people will hold you accountable for what...saving there life! Ive never heard of that before.Ive been taught that if theres a code violation or a problem that can be life or death is to disable it.You are the last person there and if something did happen you could be held liable for negligence for not shutting it down!WOW I guess theres different laws everywhere. Well what about your consience?

kenmac · 03-24-2011, 10:08 PM

All I'm able to do is turn off the gas supply to the furnace & try to get the customer to sign a form stating why I turned it off & that the furnace shouldn't be used until repaired/replaced. If they choose to relight & continue to use . There's nothing more I can do. It's their furnace & property. Gas co. here isn't allowed to turn their gas off as, they may have other gas appliances that are in use. Only time gas co. will turn gas off is if the bill isn't paid

1mastertech · 03-24-2011, 10:25 PM

Quote:

Originally Posted by kenmac

All I'm able to do is turn off the gas supply to the furnace & try to get the customer to sign a form stating why I turned it off & that the furnace shouldn't be used until repaired/replaced. If they choose to relight & continue to use . There's nothing more I can do. It's their furnace & property. Gas co. here isn't allowed to turn their gas off as, they may have other gas appliances that are in use. Only time gas co. will turn gas off is if the bill isn't paid

yA..10-4 ITS CRAZY ESPECIALLY WHEN YOU EXPLAIN THE RAMIFICATIONS TO THEM.tHANKS FOR THE POST MY FRIEND!

Doc Holliday · 03-25-2011, 01:01 AM

Quote:

Originally Posted by hvaclover

.) your sense of duty is commendable .2) but in the end only the customer will have the right to close down a furnace.

3.) our city won't enforce a shut off. its all about liability.
t

1.) I agreee and applaude 1mastertech.

2.) bull hell.

3.) Mine will. We disable systems, call the city and they will come and confirm our findings of CO and turn off the gas to the home, quickly. If the homeowner/tenant doesn't like it, too bad. At least they are alive to complain.

12-14-2010, 01:13 AM	#1
KarlJay Member Join Date: Dec 2009 Posts: 152	old wall furnace makes banging noise I'm moving my old wall furnace, it's fully disconnected and I want to fix the banging noise that it's made for the last 15 years I've had this house. The house is over 70 years old and I don't have a clue as to the age of the furnace, I know it's at least 30 years old. The furnace works fine, but when it cycles off, it makes a series of banging noises as it cools down. I don't want to replace it with a new one at this point. Is this a common problem with old wall furnaces? My guess would be the metal above the flame where the heat transfers is too close to a mount and the expantion/contraction of the metal is where the banging happens. Any input / hints would be great... Thanks, KarlJay. I have a TIG welder and pretty extensive set of tools for metal working, so I don't mind making something that'll fix this.

12-14-2010, 03:17 AM	#2
hvaclover Member Join Date: Oct 2008 Location: Suburbs of Detroit Mi Posts: 3,702	old wall furnace makes banging noise That could very well be a cracked heat exchanger. Wall furnaces are dirt cheap. Why not just buy a new one since you are moving it? You have nothing to lose except high fuel bills. __________________ Just slow, not stupid.

03-17-2011, 01:56 AM	#3
userCA Newbie Join Date: Mar 2011 Posts: 1	old wall furnace makes banging noise I have the exact same problem with a wall furnace and am trying to figure out how to fix it. My landlord wants to replace the vent pipe, because he thinks the pipe is expanding/contracting and making the banging noise. But now I'm thinking it may be a problem with the wall furnace heat exchanger itself. What did you find out about yours? Was it a cracked heat exchanger that was making the banging? If not, how did you fix it? Thanks!

03-22-2011, 08:34 PM	#5
KarlJay Member Join Date: Dec 2009 Posts: 152	old wall furnace makes banging noise Update: I haven't addressed this issue yet, might just buy a new replacement. As far as your's having a crack, I'd go get a CO detector TODAY. I got scared and bought one last year, everything is fine as far as CO goes. The concern is that CO doesn't have an oder, so you can't tell if you have a leak. Mine went off once when I had an old muscle car idleing in the driveway with the front door open. Couldn't tell anything except for the CO alarm going off. It can KILL you...

03-23-2011, 12:21 AM	#6
unicursalhex HVAC Supermodel Join Date: Jan 2011 Location: Wa Posts: 167	old wall furnace makes banging noise Yeah the detector is a good idea. I did a furnace maintenance a little while ago and found a big gaper right behind the heat exchanger limit. I shut the valve off and informed the old guy who owns the place that carbon monoxide is spilling into his house and that he needs to replace the unit. Before I could get my tools loaded he was turning the valve back on and running the furnace... Just did a follow up call today and he said he's going to replace it but he has some other things that are more pressing. Wow, whats more pressing than carbon monoxide poisoning? He's an old guy so he's set in his ways, hopefully that crack doesn't open up even bigger and give him the dirt nap... __________________ Mark it zero!

old wall furnace makes banging noise