Hot water from cold taps

Hi

I'm a newbie and don't claim to know anything about plumbing but I've got warm/hot water coming from all the taps which are fed by the "cold" water tank in the loft. It stays hot even when you run the taps for several minutes so I think hot water is somehow flowing into the cold water tank.

I don't actually have central heating, this is part of a system with a hot water cylinder in an airing cupboard and pipes going to the bathroom and kitchen. The hot water cylinder is electrically heated and I think it is unusually hot. I can't find a thermostat so am wondering if it is overheating somehow?

Does this sound dangerous? It certainly doesn't seem desirable or good for the electricity bill.

Any thoughts or ideas would be appreciated. Thanks!

Dan ("Barq")

Do you have any mixer taps fitted somewhere in your house? It sounds like one might be letting the water through.

If you have a direct cylinder, the thermostat should be located on the immersion heater itself (under the plastic cover).
There won't be a visible thermostat strapped to the tank.

It sounds like the thermostat has failed.

TURN THE HEATER OFF!!!!!!!

Just put it on for long enough to heat the water you need, when you need it, then turn it off. Get the thermostat replaced asap.

I don't intend to be alarmist, but YES THIS IS POTENTIALLY DANGEROUS. If you have a plastic cold water tank, it will be seriously weakened if the water temperature rises significantly. Then you could be faced by a deluge of scalding water.

You would not be the first to suffer this, and it has been fatal!!!!!!!!

barq if you read that and haven't turned it off,
TURN IT OFF NOW!!

Hi Everyone

Thanks for your thoughts/warnings. My hunch was that it was getting too hot so I had limited the timer on the heater to 30 minutes in the morning, I might take that down to 15 minutes since this is about the time needed to warm up the tank from cold but no more.

The theory about water leaking through the mixer tap is interesting. However, I've been crawling around feeling for "warm" pipes and suspect that there is no leakage from the hot tank to the cold through the tap (of course this doesn't exclude the possibility of it going the other way).

I suppose the one good thing about this being potentially so serious is that *hopefully* my landlord will take it seriously as well! Anyway, cheers for the advice, at least I know what to do now.

Dan ("Barq")

I have seen some strange failures of components in my time, and in this case, I would NOT rely on a time switch. They are very reliable, except when they fail, which is VERY rarely, but in your situation you are treating it as a safety critical component.

DON'T!!!!

Turn off the supply yourself until you want to use it, then you will have an extra layer of safety.

You are free to ignore this, and we'll all be around to say "I told you so", I'll repeat my warning:

People have DIED from this. (More correctly, they have been killed by it)

Right, point taken. I'm going away for the weekend so can just switch it off and then get someone in next week to take a look at this.

Can I just reiterate how much I appreciate this advice. I had no idea whether this was even a problem (I think I mentioned I know nothing about plumbing) so probably would just have left it but for the suggestions here.

Dan ("Barq")


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