mixer shower cold pipe hot

[nigel206]

got a mixer shower installed but recently the cold feed pipe is getting hot. the hot water seems to be making its way from the hot pipe via the mixer unit then along the cold feed.. very strange.. any ideas what it is and how to fix it ?
Thanks
Nige

 

[Nige F]

Unequal pressures...hot higher than cold

 

[nigel206]

hmm... is there a solution ?
Thanks
Nige

 

[Slugbabydotcom]

A bit more info about how your mixer shower is fed would help.
A couple of non return valves in the pipes leading to the shower would help unless the shower was fed from a gravity supply. If you do have a gravity supply is there a dedicated cold supply running back to the same header tank that feeds the hot water side?

 

[nigel206]

Hi
The cold pipe is taken from the feed going to the tank in the loft, Tee'd in the airing cupboard.
The hot pipe is taken from the hot water out pipe of the hot water tank.
Its gravity fed.
The strange thing is this has been in place for about 2 years, and has only recently started happening... I think !.... I certainly hadnt noticed it before.
Could it be a fault with the shower mixer unit ?... make unknown.. I think it was a b and q jobby !.

Maybe the simplest answer is to replace the unit .... a bit expensive if it doesnt work though

Regards
Nige

 

[Bahco]

You need to feed it off a new connection in the cold water tank. Should be lower than the cylinder feed if poss.

 

[Slugbabydotcom]

The cold pipe is taken from the feed going to the tank in the loft, Tee'd in the airing cupboard.

I have the following ideas on this ... most likely first

1. A possibility is that there may be an integral non return valve in the mixer that has failed.
2. Check that your shower rose isn't blocked
3. Strictly speaking the cold water for your shower should come directly from the header tank and not teed in to the pipework.
4. Any other draw off from this pipe could cause the pressure imbalance. Is there anything else teed into it? A restriction on this pipe such as a valve not opened fully somewhere near the tee end could also cause the problem.

 

[l9nux]

Hi,

I've just had the same problem happen to my power shower which is installed in exactly the same way. This morning I found that the shower is always hot, and the cold output from the pump was hot too.

Could something be stuck in the pump? I am wondering this because only yesterday I had to turn off the water supply to fit a new washer in my toilet valve. That would have drained the cold tank in the loft, so could some dirt have found it's way into my shower pump?

Before I start taking things apart I thought I'd find out what the solution to nigel206's problem was?

Thanks,

Ray.