Shower goes cold after 5 minutes

Beanikki · Dec 17, 2017

hi everyone

I’m a novice in terms of diy but wonder if you can advise me at all.

I had a new combi boiler fitted in September and everything has been fine until now.

My shower is one that comes off a mixer tap on the bath. For some reason it now goes cold about 5 minutes into a shower.

My hot water comes off the combi and the cold is direct off the mains.

If I don’t put the cold water on at all then the shower runs hot constantly with no problem. If I put the cold on even just a little bit then after the 5 minutes everything goes cold.

If I turn the cold tap off when this has happened then the hot tap continues to run but the water doesn’t come back to hot. I have to turn the hot tap off and back on again to get the hot water back.

I’m not sure why this has started happening now. My cold water has always been high pressure but it hasn’t changed that I can tell.

Any advice of simple things I can try? If I call the boiler people to come out I’m not sure if I’d be covered as the hot water is fine without the cold tap being on so it’s not the boiler that’s at fault (or is it?).

Thanks everyone

jtsplumbing · Dec 17, 2017

Beanikki said:
hi everyone

I’m a novice in terms of diy but wonder if you can advise me at all.

I had a new combi boiler fitted in September and everything has been fine until now.

My shower is one that comes off a mixer tap on the bath. For some reason it now goes cold about 5 minutes into a shower.

My hot water comes off the combi and the cold is direct off the mains.

If I don’t put the cold water on at all then the shower runs hot constantly with no problem. If I put the cold on even just a little bit then after the 5 minutes everything goes cold.

If I turn the cold tap off when this has happened then the hot tap continues to run but the water doesn’t come back to hot. I have to turn the hot tap off and back on again to get the hot water back.

I’m not sure why this has started happening now. My cold water has always been high pressure but it hasn’t changed that I can tell.

Any advice of simple things I can try? If I call the boiler people to come out I’m not sure if I’d be covered as the hot water is fine without the cold tap being on so it’s not the boiler that’s at fault (or is it?).

Thanks everyone

These sort of shower attachments are not the best thing to use a very good risk of being scalded because you cant control the temperature and an imbalance of water pressure, you would be better to install a proper thermostatic controlled one, or an electric shower