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noisey pipes

Dave_4 Member Posts: 1,405
What is the pressure reading at the boiler? What is the temperature at that point?

I suspect of this is an old gravity HW system (attic tank being a give-away), that the piping is pretty large. For this reason I have to wonder why banging is notable. Large pipes, if encountering air, tend to gurgle gently, not bang.

Banging has me thinking high temperature expansion (sure this is not steam?).

If air is a condition (causing noise or not but possibly causing "no heat" radiators) it is bled at the tops of the system and most often at each radiator.

Key operated vents are usually present. Some can be vented with a screwdriver, some with a special key available at any good plumbing supply house.

Venting gravity HW systems can be a challenge, it may take a lot of trips up and down the stairs.


  • tsnel
    tsnel Member Posts: 4
    noisey pipes and cold regesters

    I have a problem w/ my heater. gas fired boiler, closed system. bladder tank in the attic. each room has a reg. but some are cold. you can hear the pipes banging. and the pressure fluctuate's. I was told I have air in the lines and need to bleed the air out. how is this done?
  • Al Letellier_9
    Al Letellier_9 Member Posts: 929
    bleeding air

    IF you don't have vents on each radiator, its a job for a pro....hire a good one and have hims show you how. From your description with a bladder tank in the attic, you have an old gravity system that was converted.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • tsnel
    tsnel Member Posts: 4

    Mr. White,
    It is more of a gurgle.
    As far as temp and press. I haven't had to use the heater yet but will be soon. if i remember from last winter, press. at 20psi/ temp 120.
    As far as it being steam there is no site glass. so I'm guessing it's not steam.
    And yes it is alot of trips up and down the stairs. I kept thinking i was doing something wrong.When I tried to bleed the system before, the press. would get so high I was afraid I was going to burst a pipe.
    Both radiators upstairs work great. the ones that get cold or not very hot are the last two. I read on some other site that this might be a diverter tee system?

    well thanks for your time and anymore info would be helpful.I know this is hard to diag. a problem when your not there cking it yourself(I work on cars)got friends calling me all the time to fix there cars over the phone.I'll probly call someone to take care of this but at least I'll know a little about what he's talking about.
    Thanks ,Tsnel
  • tsnel
    tsnel Member Posts: 4

    Thanks Mr.Letellier
    I think I will hire this job out. The house was built in the early 50's I think it is the org.
  • Dave_4
    Dave_4 Member Posts: 1,405

    I will assume hot water- no reason steam would run as high as 20 or we would read about it.

    You should make sure you have a working pressure relief valve. For a house this would be a fixed one, factory set to trip at 30 PSI. I doubt the pressure is enough to burst the pipes.

    Normally the system should be about 12 PSI at the boiler for a two story house, 18 PSI for a three story house, when cold. Add about 6 lbs. for when it is hot. If the pressure has risen so much when heated that your relief valve let go or began to weep, you need more expansion tank capacity.

    If this is a diverter-tee system there is a lot more to look at. Each radiator feed would have a pair of branches, supply and return, emanating from the same single main. I take it you read that chapter on diverter tee heating and you may want to do so again. Also take advantage of Dan's books ("Pumping Away" may be of particular importance to you here).

    As you said, get someone to look at it- that is the best thing if you are not confident.
  • tsnel
    tsnel Member Posts: 4

    thank you for your advice.

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