Gas and Oil Home Heating Furnaces - Severe Pipe hammer around boiler
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Hetch
11-09-01, 07:58 AM
Hello All,
I am a new (lucky)home owner and am having a blast with a large 91 year old home. I have a gas boiler/hot water heat system (I dont know if it was convereted from a gravity, but its got a circulator pump now)that is keeping me up all night with pipe hammer.
My system:
(as best described by me...pardon my ignorance)
I have a gas-fired boiler about 10 years old with a 30lb relief valve. The water pipe system is black iron pipe (except around the feed/return at the boiler). There is a single copper feed/return coming out of the boiler, but then it tees off into 2 separate black iron supply/return lines that go off in separate directions. It looks as if a boiler was replaced that had an old split system with a supply/return on each side of boiler, that has since been converted. The system has a circulator pump (not a gravity system). The house has three stories, and all of the radiators seem to be operating ok...some get hotter than others. I have an older looking black drum expansion tank tucked beween the joist above the boiler. Also, there was a kitchen/hallway addition that now adds a radiant floor heat system that is on it's own zone (has it's own t-stat and regulating valves).
My problem: Heats the house ok, but about every hour the pipes bang like crazy around the boiler (almost as if hot water/pressure is being released from the boiler and expanding the pipes immediately surrounding the feed line). I have noticed that in most cases, it is when the system is not calling for heat. Maybe the pilot is heating water in the boiler? Anyway, I noticed that this pipe banging also occurs on the pipe that runs over to and including the exp tank. The feed lines immediately get hot, and only the first couple radiators on the loop get hot. When the system calls for heat (It's on a programmable T-stat..controls by Honeywell)all the radiators work ok and the house gets heated. Pressure at the boiler is around 17-20 psi.
[This might be important- when I first turned the heat on a coule of weeks ago I severly over-filled to the point where water flushed out of the relief valve. When I turned the heat on the guage was pegged well over the 30 psi...hence the hot steam bath in my basement. Knowing what I had done, I bled the system from the radiator furthest from the boiler until it dropped down to 15-20 psi. All of the radiators have been bled.]
Is my expansion tank full? Air in my lines?
Hopefully you can give me some advice that I can do myself....I got no money for a contractor right now...been a real bad month.
please help..thanx
Hetch
I am a new (lucky)home owner and am having a blast with a large 91 year old home. I have a gas boiler/hot water heat system (I dont know if it was convereted from a gravity, but its got a circulator pump now)that is keeping me up all night with pipe hammer.
My system:
(as best described by me...pardon my ignorance)
I have a gas-fired boiler about 10 years old with a 30lb relief valve. The water pipe system is black iron pipe (except around the feed/return at the boiler). There is a single copper feed/return coming out of the boiler, but then it tees off into 2 separate black iron supply/return lines that go off in separate directions. It looks as if a boiler was replaced that had an old split system with a supply/return on each side of boiler, that has since been converted. The system has a circulator pump (not a gravity system). The house has three stories, and all of the radiators seem to be operating ok...some get hotter than others. I have an older looking black drum expansion tank tucked beween the joist above the boiler. Also, there was a kitchen/hallway addition that now adds a radiant floor heat system that is on it's own zone (has it's own t-stat and regulating valves).
My problem: Heats the house ok, but about every hour the pipes bang like crazy around the boiler (almost as if hot water/pressure is being released from the boiler and expanding the pipes immediately surrounding the feed line). I have noticed that in most cases, it is when the system is not calling for heat. Maybe the pilot is heating water in the boiler? Anyway, I noticed that this pipe banging also occurs on the pipe that runs over to and including the exp tank. The feed lines immediately get hot, and only the first couple radiators on the loop get hot. When the system calls for heat (It's on a programmable T-stat..controls by Honeywell)all the radiators work ok and the house gets heated. Pressure at the boiler is around 17-20 psi.
[This might be important- when I first turned the heat on a coule of weeks ago I severly over-filled to the point where water flushed out of the relief valve. When I turned the heat on the guage was pegged well over the 30 psi...hence the hot steam bath in my basement. Knowing what I had done, I bled the system from the radiator furthest from the boiler until it dropped down to 15-20 psi. All of the radiators have been bled.]
Is my expansion tank full? Air in my lines?
Hopefully you can give me some advice that I can do myself....I got no money for a contractor right now...been a real bad month.
please help..thanx
Hetch
resercon
11-09-01, 08:15 AM
Drain your expansion tank. Every thing esle you said sounds okay.
Hetch
11-09-01, 08:44 AM
I was hoping your reply would be that simple.
Draining my tank...not that difficult?
If I have an older tank, how do I know when to stop draining? I need to have 1/2 water 1/2 air correct?
Draining my tank...not that difficult?
If I have an older tank, how do I know when to stop draining? I need to have 1/2 water 1/2 air correct?
resercon
11-09-01, 09:12 AM
You're thinking of an expansion tank that has an air bladder in it. The older tanks should be completely emptied.
Hetch
11-15-01, 01:31 PM
I received the advice to drain my expansion tank to stop the pipes around the boiler from banging. However, my expansion tank, as I said before is tucked between joist above the boiler. There is a copper line that arms over from the boiler feed to a drain **** directly underneath and connected to the tank. When I open the drain **** below the tank water is being pulled over from the feed rather than the tank emptying. Is that a normal set up?
Is water coming out of the tank?
There is a set screw(pressure reg) on the drain **** between the tank and tap, but as I said, no shut off to stop from pulling water from the system.
Im a bit confused. That pipe that arms over to the tank is the one that bangs the loudest.
Please help. Tired of filling/bleeding, filling/bleeding this system to get rid of this noise.
The noise comes mostly during mid day and during the night, when the T-stat is turned down.
Is water coming out of the tank?
There is a set screw(pressure reg) on the drain **** between the tank and tap, but as I said, no shut off to stop from pulling water from the system.
Im a bit confused. That pipe that arms over to the tank is the one that bangs the loudest.
Please help. Tired of filling/bleeding, filling/bleeding this system to get rid of this noise.
The noise comes mostly during mid day and during the night, when the T-stat is turned down.
resercon
11-15-01, 02:55 PM
I suggest you change the expansion tank. These tanks only cost about $35. and the new type you don't have to drain water from. You might want the contractor to go over the unit and make sure everything is alright and at the same time you can ask him how the system works.