so I live in a 1950's era bungalow, and a few weeks ago I started to hear I 'hammering' noise in the upstairs wall whenever the downstairs water taps were turned off. Before I hire a plumber to the tune of $$$ does anyone have any advice for me?

  • 2
    A simple thing to try is to drain the entire system and then refill it. So turn off main incoming valve, open all taps, flush all toilets, etc. Then turn main back on and once all air clears out of each tap you can turn it off.
    – topshot
    Sep 18, 2016 at 16:56
  • Has anything changed, or did this just start happening? Do you have a pressure regulator on the main supply? I'd start by measuring the supply pressure, as increased supply pressure could lead to suddenly having water hammer issues. You should be able to pick up a pressure gauge for about $10, that will fit on a hose bib.
    – Tester101
    Sep 18, 2016 at 23:34
  • In the olden days, before water hammer arrestors existed. Plumbers used to leave vertical pipes filled with air, that would absorb water hammer. However, over time these pipes slowly fill with water. If you have these, draining the system will "recharge" them.
    – Tester101
    Sep 18, 2016 at 23:38

1 Answer 1


If there are taps or a bathroom up stairs a small leak can cause water hammer make sure all the water is fully turned off and the problem will stop. There needs to Be water flow to create water hammer.

  • 1
    Nonsense. Water hammer is caused by the sudden stoppage of flow (at the taps being turned off) it does not require flow elsewhere to affect other places, as the shock wave travels through standing water in the pipes.
    – Ecnerwal
    Sep 18, 2016 at 23:41
  • I have observed water hammer from small leaks it is not the normal thump thump but a vibration of the pipes. It is still water hammer! And water hammer can be created in some plumbing with a constant flow.
    – Ed Beal
    Sep 19, 2016 at 7:35
  • I agree. The most violent water hammer I've observed was in a 1970's home and involved the drinking water tap in the kitchen. Turning it on a bit resulted in repeated hammering in the supply pipes.
    – isherwood
    Feb 27, 2017 at 15:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.