Banging Pipes

Ratman

I have loud banging when my steam heat kicks on. Is this due to overfilled water level? I drained some water (very rusty and sludge like) but maybe not enough becasue it was still bad after. My glass tube shows about 1/3 full. How much should I drain? Also, some pretty loud hissing from some radiators. Should I replace vents on radiators??

Thanks

Jamie Hall

That's water hammer...

most likely.



First off on draining -- the sight glass should be about half full, or a little higher.  If you have the manuals for your boiler, it will say.  More draining may not help much -- but it is quite possible that skimming might.



But to really address the hammer problem, one needs to know...

One pipe or two pipe system (sounds like one pipe, from the radiator vents)?

What is the near boiler piping like (pictures help a lot!).

Are the steam mains insulated?

Did this start recently?  After work was done?  If so, what sort of work was done?

Are all the pipes pitched to drain properly?

Are alll the radiator valves open all the way?



The loud hissing from the radiator vents suggests the possibility that the pressure may be too high, although that's not conclusive -- the pressure control (probably a pressuretrol?) should be set to cut in at from 0..5 to 1 psi, and cut out at not more than 2 psi, to begin with.

Ratman

water hammer

Thanks Jamie - we did have some work done last year and added a few radiators with a renovation. the near boiler piping had to be re-routed because of a steel support beam that needed to go over furnace. But, did have this problem before renovation. I believe it is one pipe. I am not home but will check pressure. The hissing is not as bothersome/worrisome as the water hammer which wakes us up and scares our 4 kids in the middle of the night!