DIY Doctor UK DIY Forums

we have been having problems with water hammer after a new mains water feed was fitted. we installed a pressure reducing valve but still issues.
lately we have narrowed it down to the Shower. every time it is turned on it make one hell of a racket and wakes the whole house in the morning.
if we flush toilet at same time its even worse !!!

because it is built in, it is not an easy thing to change!!

searching for answers, i have read that non return valves may be the cause ??
does the shower have them, if so where are they ??

any ideas

TIA

try turning the pressure down at the main incoming stop cock

lets have a look wrote:try turning the pressure down at the main incoming stop cock

i have a pressure reducing valve fitted !!! so what difference will turning the stop cock down make ???

ok valid point, I have been doing domestic plumbing for 40 years and have never fitted or seen a pressure reducing valve fitted in a house or flat,only in multiple occupancy where anyone can adjust the stop cock, so am at a loss to why you had one fitted instead of reducing the pressure at the stop cock.
A non return valve to a shower should be located at a point where it's accessible,airing cupboard,in a panel,under the bath,but again never fitted them.
I would change the inlet valve to the cistern,this is the most common place to get water hammer (in a ballvalve) or if there's a isolation valve on the pipe do a test by turning it off,I take it that the shower and wc are mains fed not tank fed ?

lets have a look wrote:ok valid point, I have been doing domestic plumbing for 40 years and have never fitted or seen a pressure reducing valve fitted in a house or flat,only in multiple occupancy where anyone can adjust the stop cock, so am at a loss to why you had one fitted instead of reducing the pressure at the stop cock.
A non return valve to a shower should be located at a point where it's accessible,airing cupboard,in a panel,under the bath,but again never fitted them.
I would change the inlet valve to the cistern,this is the most common place to get water hammer (in a ballvalve) or if there's a isolation valve on the pipe do a test by turning it off,I take it that the shower and wc are mains fed not tank fed ?

Hi,
the reason we had a reducing valve fitted is so we can actually see what pressure we have incoming. the non return valves are fitted to the showers main body along with the filter. i removed them yesterday and apart from a small amount of limescale they seemed to be working fine. refitted and it has made a difference but not much...
you mention the inlet valve to the cistern ???
i take it you mean the toilets? all the inlet valves have been replaced with high pressure ones as this was the first place i started when water hammer became apparent. i also isolated them one at a time then all of them together but makes no difference..
thank you for your response