Cold water from some hot tap, and some cold taps warm.

[DarkHorsey]

Some advice please from those in the know would be greatly appreciated.

I have a hot water problem, whereby the hot water on some taps runs nice and hot, but on others it is cold.

We have a pressurised system in the house since a loft conversion 5-6 years ago, and have no cold water tank any-more. The boiler is working fine, and the hot water tank is piping hot.

We do also get a problem with the cold water sometimes running hot on some taps for 5-10 seconds.....really strange.

This all started about a month ago, but seems to have been getting steadily worse.

Today I thought I would try to resolve the problem by draining the entire system (hot system, and heating), but this has not changed anything, and the problem continues.

One thing that I have noticed as a temporary solution to get hot water from one of the taps that refuses to run hot in the bathroom, is to turn on the offending sink tap (it will run cold), and then turn on the bath tap (which also runs warm), and then the sink tap goes hot.

Any advice?

[stoneyboy]

DarkHorsey ,
A bit more information please.
Are you saying that you have mains fed hot water cylinder?
end

[DarkHorsey]

Yep, the hot water cylinder mains fed.

It is really weird, but I can get the hot tap in the bathroom sink working by the following steps;
1. Turn sink mixer tap to hot, and turn on full (sink tap it will run cold).
2. Turn bath thermostatic mixer tap to hot, and turn on full (bath tap will run warm, not hot).
3. Sink tap will now become hot.

If I turn the bath thermostatic mixer tap off, sink mixer tap will go from hot to warm.

This is driving me crazy, as the system has been working fine for years, and now it is playing up, and there have been no changes to the system at all to cause this change.

Any advice would be apreciated.