"We have a dual exposed thermostatic shower. To obtain water at a decent temperature the flow rate is just a trickle. However the waster pressure is good as the taps on the bath has good pressure at the same temperature when mixed "manually". Is this an issue with the thermostatic valve and if so would you replace the valve or the whole shower

Hi Jon

I would start by disassembling the unit and taking it apart so that you can clean it. When all parts are out of the valve, pulse the water on to clear the valve body of any settlement/debris.

Start there... post back with results.

Mark