Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Knocking Radiator

Cheylulu Member Posts: 1
Hello! My radiator has been making really loud banging noises for about two weeks. I've left multiple work orders for my super but haven't received any info on it nor has the problem been resolved. It bangs loudly all night and I haven't been able to sleep at all.

Is there anyway I can fix this problem myself seeing as no one seems to be interested fixing it for me?


  • Fred
    Fred Member Posts: 8,542
    Is this a one pipe or two pipe system? One pipe means only one pipe, with the supply valve at the radiator. If two pipe, there will be a pipe on the supply side of the radiator and a drain pipe on the opposite end.
    In either case, make sure the radiator has some pitch (towards the supply pipe, on a one pipe) or towards the drain pipe on a two pipe. You can shim the end of the radiator up with wood shims or checkers or quarters under each of the two end legs to get pitch.
    Also, if this is a one pipe radiator, make sure the supply valve is fully open. If it is closed or partially closed, steam can get in but condensate can't get out and that can also cause banging.

    If the banging seems to be coming from under the floor, near the radiator but not actually the radiator, you may have to try and raise the entire radiator a half inch or so and then pitch the end of the radiator. That will re-pitch the horizontal pipe under the floor.