Leaky overflow

[BliarOut]

One of my overflow pipes above the back door is occasionally leaking. At the moment I can't remember which one does it!

I have two tanks in the roof and an immersion in the airing cupboard.

My thoughts are it's the larger of the two as the limescale lines go up to the overflow on that one.

When I turn the hot water on the overflow stops although it may take a couple of goes.(ball valve settling?)

any ideas what's about to fail?

[robinhood21]

Sounds like it is the ball-valve on the cold tank in your loft. Might be able to adjust the B/V arm by bending it down slightly (if brass). Or replace the B/V washer. Personally, I would replace the whole B/V as they only cost about a fiver.

[Simpo Two]

robinhood21 said:

Might be able to adjust the B/V arm by bending it down slightly (if brass).

That would be my first fix too, but it may be a sign that the valve is clagged up or on the way out.

[Ricky_M]

If it stops after you run a hot tap, probably the ball valve in the cold water storage cistern is passing.

Just replace the whole thing. Turn water off, don't touch the part that goes through the wall of the tank, just undo the big nut on the valve on the wet side of the tank, remove old valve, undo big nut on new valve and fit it to the existing part of the old valve.

Place the old ball on the new valve and bend the arm to set the water level.

[BliarOut]

I *think* it could be the ball valve in the cold tank, it feels a bit flaky. What purpose does that cold tank serve? All my cold taps turn off immediately when I turn the incoming stopcock off so none of my cold supply is tank fed.

Chalet bungalow if that helps.

[robinhood21]

It will be supplying your hot water tank.

[BliarOut]

Makes sense, thanks I'll go get a ballcock in readiness for the next time it plays up