Water Hammer

MP4691

I live in a semi d house. Never had a problem with noise in the attic when flushing the loo. Lately when I flushed the loo it felt like the ceiling was going to come down. Plumber told us it was water hammer. The ballcock was replaced as the seal was gone. All was good but then it started again. Another ballcock was put in and also a biworld water arrestor. The problem persists and a gurgling can be heard in the hot press tank. Any ideas what to do?

John.G

Maybe worth monitoring mains pressure, if very high, say > 4.5bar maybe install a PRV (pressure reducing valve).
Has your neighbor done any plumbing work recently and hopefully didn't install a booster pump on his mains?.

MP4691

Neighbour has not had any work done. How would I check water pressure or is that done by a professional? Wher3 would you fit a PRV valve (sorry a complete novice)

John.G

You would need your plumber back but another few queries.

Is it the loo ballcock is gone, if so then this (if upstairs) is/should be fed from the cold water storage tank in the attic, and there may be a problem with this (storage tank) ballcock. Are both ballcocks the traditional type ie a plastic ball on the end of a rod?.

MP4691

Hi. Ballcocks were replaced twice in the attic. Yes they are the traditional type. Will contact plumber to check water pressure as you suggested. Many thanks.

John.G

I read somewhere else that had a similar problem and they cured it by installing LOW pressure nozzles in the attic tank ballcock, normally the low pressure nozzles are installed only in the toilet ballcock (these have a bigger bore nozzle), the high pressure ones have a smaller bore for the higher pressure so seems a bit strange that replacing it with a bigger bore nozzle cured the problem but it did in this particular case.

K.Flyer

Have your plumber fit a FluidMaster Pro 75 B. Must be a brass shank.
I fit them all the time to deal with issues like this and that's the end of the problem.

John.G

What's wrong with using a yogurt cup?, much cheaper.

K.Flyer

John.G wrote: »

What's wrong with using a yogurt cup?, much cheaper.

Unfortunately I don't carry yogurt cups in my van, plenty of FluidMaster Pro valves though.

MP4691

https://boards.ie/discussion/comment/116354256#Comment_116354256

Hiya

Meant to reply a while ago. We got what you recommended and our problem has disappeared. Thanks once again for your help and assistance.