Have a thermostatic tap in bath - a Metro 3 hole shower valve & bath filler. Even when put to hotest only getting lukewarm water. Have checked and is not an issue with hot water supply - water to tap in sink beside bath is very hot. Have had the tap for about 6 years - never had problem before. Any suggestions?

Tony C, January 2010

I have the same problem with a metro thermostatic shower valve. I've removed the valve but cant see any way to adjust it. Has anyone got any ideas ?

carlw, January 2010

I'm unfamiliar with modern thermostatic taps, but if they work on the bi-metallic strip principle, there are very small movements indeed (by the bi-metallic strip) actuating other bits. In my limited experience, hard water eventually builds scale deposits sufficient to prevent these small movements. I had a Mira shower operating on this principle in SE England where the water is so hard it's barely liquid. It had to receive 6-monthly dismantling/ descaling to work correctly.

Colin, January 2010