Hello,
Heating no problems. Hot water downstairs no probs. Bathroom (upstares) when shower is on it run's hot and cold same with bathroom sink? (and lots of noise from pipes and boiler?? )

Could you rephrase or better describe what you mean with"when shower is on it run's hot and cold same with bathroom sink"

Hello,

When taking a shower the water is nice a hot the it goes cold then hot (and so on). The bath tape is the same??

Thank you Dave.

Hello,

When taking a shower the water is nice a hot the it goes cold then hot (and so on). The bath tape is the same????

Thank you Dave.
If you're having the same problem with the bath tub faucet.( we are talking about two different faucets aren't we?) then that puts the focus on the water heater. If the bath and shower faucet are one and the same then do you have a posi-temp tub and shower valve? Please clear up my confusion about the two faucets. Tom