Hot water out of the cold tap?

Flashfly

I fitted a new bathroom a couple of years ago and all went well. I did the plumbing myself and fitted a thermostatic shower valve where you have a two inlet supplies (hot and cold) and two outlets (for the bath tap and shower head).

Recently we've been noticing that our cold water supply at the sink comes through hot. We thought it was something to do with our flat's communal cold water supply but today I've taken off the bath panel to investigate. It seems that the hot water supply going to the valve is 'leaking' across the valve and forcing its way into the cold supply pipe.

Does this sound possible? Should I have fitted (and should I now fit) a non-return valve to the cold water inlet to the shower to solve this problem?

ormus

sounds more like a seal or valve problem inside the mixer valve.
you can fit NRV in the lines. i did it to mine after advice from a corgi man, who told it was a legal requirement.
found out afterwards that it wasnt required legally, as my shower head is fixed.

carolinosourus

I don't know if this helps at all but at my boyfriends house the cold water tap in the kitchen always runs hot/warm to start with as the cold water pipes run alongside the hot water pipes... or that was what I was told!

Flashfly

Thanks for the advice. I have fitted a Non-Return Valve and it has solved the problem. I think the neighbours are going to complain though, they will have to start heating their own water from now on! :eek: