Shower running luke warm (combi fed)

[PhilHarris007]

I have an en suite shower which runs Luke warm but when i turn the bath tap on right next to the shower, the shower water heats up. It sounds like too much cold in the shower valve but what is the cure?

Thanks

 

[flameport]

If the other hot taps work normally, then the shower valve is seized / jammed with limescale / worn out.
May be possible to buy a new cartridge for it, or alternatively just replace the entire thing.

If similar problems occur with hot taps including them going hot/cold/hot when in use, then there is a problem with the boiler.

 

[mcmoby69]

Turn the cold feed off to the boiler and open a hot tap. The water should stop running after a minute or so. If it doesn't you have a non return valve problem somewhere.