New to a house with a HW boiler : Questions

Old 11-08-13, 10:11 AM
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New to a house with a HW boiler : Questions

Last year we moved into a 60+yr old house with an old hot water boiler. Our house is a split level and the heating is split on 3 zones. We have baseboards on the top floor and main floor and radiant heat on the lower floor (walk out level). The finished basement is not heated/cooled.

System worked all last year : however, we had constant banging in the pipes on the top 2 floors. Local utility provider, who provides 'worry-free' service, did a service to the system and replaced the pressure relief valve, pressure gauge, reducer, and installed an air separator siphon. It worked and was little less noisy - he said he did all he could to remove air from the system.

This year, same deal with the noisy/banging pipes. Utility provider inspected the system and indicated all is good. When asked about the noise, indicated he didn't think it was air in the pipes (b/c the return pipe was hot). He thought it could be sediment or the pipes are rubbing somewhere along the system causing the noise.

Last night the noise seemed to be louder and more frequent than in the past.

Currently, the boiler pressure, when heat is not being called for, is around ~15psi and ~140deg. I cranked up the thermostat for each zone to check if working - it does, the unit kicked up to ~20psi and ~180deg (which i understand to be the normal operating range). Is a 40deg drop normal?

Any thoughts on the noisy/banging pipes? Does sediment cause the banging and is it worth treating the water (a chemical the keeps the sediment suspended)?

Any input would be greatly appreciated.

Old 11-08-13, 11:22 AM
Join Date: Sep 2013
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When is the banging happening? Is it durring the radiator warmup phase or is it once they are fully up to temp? I never realy had a banging problem when I had air in my pipes. I can hear the water/air moving thru them though.

When I bought my house I had a bad bang problem durring heatup. Once at temp it was quiet. I found a couple of problems to fix. First was a couple of holes where the pipes fed up thru the floors were too tight. This would cause a loud poping noise durring the warmup part of the cycle. The tough one to find and fix was the real loud bang during heatup and cool down. Only did one bang each time. I finaly found it when doing some work in the basement and had the ceiling opened up. (tile ceiling) I found they had run the supply pipe for the living room parralell to the floor joist and had it going thru the "X" bridging. There was a knot plug sticking out of one of the boards in the bridging. When the pipe would heat up and expand it would press against that knot untill enough pressure built up and then it would jump over it and bang into the board on the other side. A clamp that allows for the expansion of the pipe solved the problem.

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