Pressure Reducing Valve with a mixer shower All aspects of plumbing questions and answers, help, tips and information

[RodA]

I’ve read the project on fitting a PRV to reduce the mains water pressure into a mixer shower so it matches the tank fed hot water pressure. The PRV suggested only goes down to 1 bar output pressure, with a 3m hot water head I believe this gives me 0.3 bar pressure on the hot, will the difference between the hot & cold pressures into the mixer shower matter, or do I need to find a PRV that will go down to 0.3 bar output?

Thanks

Rod

[plumbbob]

This is not the recommended way of installing a shower. It is true some modern showers can cope with (and even supply different regulators to allow connection to) unbalanced water supplies but to be honest, I have seen mixed results with temperature control and I doubt if the installation would comply with any manufacturers installation instructions.

A majority of showers require totally balanced supplies so the PRV won't work satisfactorily. Why do this anyway? Just drop a cold feed from the header tank and do the job properly.

[RodA]

If I could drop a cold feed from the header tank I would, it would involve a vast amount of work to get it to the new shower room location. I'm now in touch with a shower manufacturer who is very helpfull. Most of the manufacturers 'technical' departments I've spoken to are nothing more than sales offices.

I'll let you know how I get on later.