On 18 Aug, 21:46, Bob Minchin wrote:
John Rumm wrote:
Patb wrote:

After replacing the ball valve, thinking that was leaking and causing
the overflow to go, I have just realised that warm water is coming up
from the immersion in the bedroom up into thelofttank.
Grateful for advice on what I should do to stop this,

Could do with a little more information to answer this...

How is the hot cylinder heated - just the immersion, or is it also
heated by the central heating?

If so, what type of central heating system; vented (i.e. with a little
header tank in theloft) or sealed (no tank, but a pressure gauge and
filling loop)?

How is the warm water getting into the cold tank? Via the feed pipe that
goes from the cold tank to the base of the cylinder, or via the vent
pipe that discharges over it?

The usual problem is a leak between the primary and secondary hot water
circuits. A new cylinder is likely to be needed.

Bob- Hide quoted text -

- Show quoted text -

OK, I drained down the tank in the loft to confirm that water is
coming up from the immersion. Sure enough, there was a steady trickle.
I also checked the smaller boiler header tank. This looks rock solid,
nowhere near over flowing.
We recently had an extension put in with 3 new mixer taps and a
shower. I isolated each mixer to see if this stopped the trickle, non
did. Could not see how to isolate the shower but took the mixer part
off the wall. There seemed to be a small non-return valve built into
the inlet on both hot and cold. I tickered with them to ensure they
could move in and out smoothly and then re-installed it. Fingers
crossed that it was the shower unit "letting by". Monitoring the water
level in the loft tank today
thanks for all the advice, I will let you know