Hot taps in bath, basin and kitchen sink stopped working

18 Dec 2008
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United Kingdom

I first noticed this very late last night - went to use the hot tap in the bathroom basin (1st floor) and nothing came out. I then checked the hot tap of the bath and got the same result. I checked the kitchen basin and a small amount came out then it very slowly came to a dribble, then stopped altogether. Cold taps work fine. I checked the HW isolation and it's not that. I can hear slow dripping in the tank above the cylinder but I'm unable to look into it to check the water level.

When I tried the taps this morning, the bath and basin were still not working, however a small amount came out of the hot tap in the kitchen but soon stopped again. I don't know what's causing the problem and I'm concerned because I'm worried about any pressure that may be building up.

Any ideas please?


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Sounds like you have an air lock in the hot water outlets. you need to find a way to push the cold supply up the hot water pipes. best way is to use a kitchen mixer tap. what you need to do is open the hot water side and place your hand over the opening, then slowly open the cold mains side, this will push the mains water back up the hot water outlet. make sure to keep your hand tightly over the tap. if there is no mixer then a piece of hose from one tap to the other. you may hear some gurgling to confirm air has been pushed back up and out. if you hear nothing do it for a few mins then try the hot water tap until it runs hot at a good flow rate.
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since all the hot taps are not working, I think it much more likely that the feed to the cold water tank is not working. It has a ball valve in it like you see in a toilet cistern. If it is a very old brass one, it may be tarnished or jammed with scale. You might be able to free it by jiggling the arm up and down, but it will jam again, possibly in the "on" position causing overflow.

you really ought to have had a look in that tank, even if you need a torch and mirror and stepladder.

I suggest you buy a new one on the way home, say it is for a cold water tank (not a toilet) as you need one that prevents contamination of the mains supply in certain conditions.

It should cost you less than £10. You need a "Part 2 float valve" and it will say something like "Water Research Council Approved" and will have a plastic bridge on the top outlet turning the water jet downwards (WC valves are not suitable) and it will be made of brass. It does not come with a ball float but you can probably re-use the old one unless it is very old. Plastic floats are very cheap.

You will need a couple of adjustable spanners to fit it.

You can actually repair old ball valves using a small kit of parts, but you will find it much easier, in cramped dark conditions, to undo the old one from its stem and fix the new one into place. You can take the old one apart on your kitchen table and repair it at your leisure as a spare for next time.


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