Thermostatic shower issue

[Madamelon]

Hi there - we have thermostatic shower with a rainfall shower head and traditional hose, which suddenly lost water pressure for hot and cold water to both shower heads. The rest of our taps have good pressure. Our plumber replaced the valve and also checked our boiler filters, but the pressure remains low. He’s stumped and we are therefore a bit stuck! Any ideas as to what could be causing the problem?

 

[Julie Street]

Is it a gravity system or a combi ?
If its gravity is there a pump?
If its a combi is it fully modulating?
Did plumber check filters and any non return valves in mixing valve?
Did plumber check pressure leaving pipes without valve fitted?
Did plumber check any isolation valves?
Did plumber check temperature of (too?) hot water reaching valve ?

 

[Deleted member 120897]

Personally I would get your plumber to check with valve removed, which would help to pinpoint the fault.

 

[king of pipes]

A blocked or failed non return valve in the shower valve is most likely ? Get it removed and tested for flow one removed this will flush out any debris also . Kop