Mixed pressure shower valves

[kccsmk]

Our shower valve recently failed and started leaking hot water even when turned off. It is an unknown make with nothing giving a clue of who made it. I decided to find a replacement but can only find a Trevi Boost that uses the Venturi principle to match our system.

Not much is mentioned of mixed pressure systems where the cold is mains fed and the hot is tank fed. All the usual suppliers offer valves that boast they are suitable for high and low pressure systems but I guess they assume both hot and cold are supplied at the same pressure. If you fit a standard one where you have low pressure hot and high pressure cold you get very luke-warm or cold water output.

We live in a bungalow where the shower head is about at the same level as the top of the hot water tank output. The header tank is in the loft the base of which is about two metres above the top of the hot water tank.

I can tell that the original owners of the house had a shower fed from the hot tank and the cold tank. The previous owners replaced that with the mixed pressure shower valve and it has worked fine until now.

So what should I do, go back to tank fed hot/cold water and if so what would be the best valve to use. Or go for the Venturi valve and use the existing hot/cold feeds I have now?
Money is tight and £300 for a shower valve seems a lot of money to me.

 

[TicklyT]

Much depends on how you prefer your showering experience. Do you want gentle rainfall, or a high pressure fire hose?

Just to throw another spanner in the works, other options may include adding a booster pump, supplied with gravity hot and cold water, or fitting a power shower.

A booster pump may make a mixer intended for higher pressures viable, and a power shower has the mixer and pump already combined in one unit.

It sounds like you have about 0.2 Bar pressure available. That should be ample for a low pressure mixer. It won't pin you against the wall with a high pressure jet, but it will still get you very wet.