mixer tap sending cold down the hot

[burts]

I have an issue where a bath shower tap mixer is sending cold directly down the hot supply. Is this fairly common? Can the mixer be repaired with a new washer?

It is a manual mixer, the old traditional Edwardian type where shower sits on top of taps.

 

[SteveP86]

I accidentally sent cold up the hot with a garden hose sink tap adapter and ended up back feeding the cold storage tank in the loft and sent water out the overflow

 

[burts]

Steve that is obvious that would happen as cold mains runs as much higher pressure that a tank fed pipe. Not sure how that sheds any sort of light on my question about a shower bath mixer internally sending water through the wrong pipe. This is a sealed system and the problem seems to be affecting the mains pressure going through the boiler therefore not allowing it to fire.

 

[muggles]

You need to put a non-return valve on your hot pipe

 

[bernardgreen]

You need to put a non-return valve on your hot pipe

This will prevent cold water getting into the hot pipes BUT the pressure of the cold water will shut the valve thus preventing any hot water getting to the shower.

A pressure reducer on the cold supply would be a better quick fix solution.