If you cannot get the pressure on the cold right down to match the hot, then there is still s samll chane of the mixer valve letting the cold across the valve and back up the hot and overflowing the cwsc.
i disagree thet the pressure reducing valve would work, its not fine tunned enough to match it up...it has not for me in the past. if you can't get the pressure down to match the hot it will travel up the pipe...as you say. A check valve will simply stop it travelling....it wont allow the hot to come down.
a pressure equalising valve cuts out all the issues.
Yes I agree Pressure Equalizing Valve is the best practice for this, but there are placement issues with them.
They have to be on the pipework to the last outlet on the supply.
If anything else is supplied after the shower pipework you cannot fit PEV.
That is why I had to use PRV and was able to get pressure down to almost match the hot supply, but it was near enough to have the shower working properly. NRV was installed as a precaution.
Pressure Equalising valves work very well on 15mm shower valves But they are 15mm therfore reducing prior to a bath shower mixer not good practice as you will get less flow on the hot also they have non return valves built in as standard which are neccesary, They also reduce flow.
Best Idea so far I think is suppling from the cold water tank if poss if the hot flow is okay now on its own then thats the easest option,or go mad and fit a single booster pump and balancing valve.
As John D Says
Best way is to run a new cold pipe from the loft tank
Hi
Im having a shower pod deliverd soon that requires a PEV to be fitted to the system or it could damage the thermostatic cassette? well anyway im running a combi at 15lpm and my cold main is 17lpm, will i still need the PEV?, if so where is the place to fit it? will it be just before the shower pod as it is at the end of the pipework in the bathroom? or does it lurk under the floorboards hidden from human hands
Thanks to all
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