Varying HW Temp

[chrisgr1962]

Hi,
By varying the water temp control on the shower mixer I can vary the temp of the hot water from other taps around the house. This is a pain as I have to go upstairs to vary the temp control (to max heat) every time I want very hot water downstairs instead of warm. The cold water supply is direct from the mains and the hot water through a combi boiler directly fed from the mains. There are no water tanks anywhere. The shower is just a basic mixer with a flow control and temp control. As far as I can tell its not thermostatically controlled, you just turn the knob to vary the temp and if someone starts using a cold tap the temp varies accordingly. This occurs even with the shower mixer turned off. The only way to prevent this is to turn off the cold supply to the mixer using a shut off valve. Any one any ideas how I can resolve this please.
Many thanks
Chris

 

[DCC]

Thats odd (although maybe the experienced will say they've seen it before) - sounds to me like the mixer valve is allowing cold water into the hot water supply, maybe the mains pressure is too high for it to cope with or its just faulty? I guess you could prove this by running the shower until the hot pipe to it is hot and the cold pipe is nice and cold, switch off the shower and go turn on one of your hot taps - if the hot water pipe at the shower starts to go cold then the mixer is letting cold water through to the hot water side and is faulty.

 

[kevplumb]

it need a non return valve fitting