Water in kitchen runs hot (very hot), bathroom sink runs hot, bath tub runs hot (when at a low pressure) but the shower runs warm(not hot)and then cold.
Adjusted temprature on boiler no difference
Boiler does make an awful racket when shower is running??

Hi kate...

A few questions, OK?

Is this a single handle shower valve? What name brand shower valve and about how old?

Back to you...

Mark

Please anwer Marks questions and we will do our best to help figure this out.

Now, just a guess, if it's a single handle shower faucet, sounds like you may have a cartridge problem, but more info would definatley help us narrow it done a bit better.

" bath tub runs hot (when at a low pressure)" tell us does the tub run cool or cold too at full volume?