overflow probs

[AnonymousImport]

HI can any one help?
I have a dripping overflow from my expansion tank.
I emptied it and replaced the ball valve.
It is still filling up and leaking.
I think it may be coming from the expansion vent.
Is it a faulty thermostat on the cylinder?
help

 

[AnonymousImport]

Strange - is the cylinder fed from a separate cold water tank in the loft? If so, and the normal water level in this tank is higher than the level of the expansion tank, you may have an internal leak in the cylinder i.e. a pinhole in the coil. This would allow water from the cylinder itself to back up into the coil, and increase the water level in your expansion tank. Unfortunatly the only way to test it is to disconnect the cylinder coil, which means a drain down of the heating system (not the hot water system), and see if water drips out of of the coil connections.

Just thought of something - an expansion tank would not normally have a vent pipe over it - the cylinder vent should be piped over the CW storage tank.

 

[AnonymousImport]

Iv,e spoken to a few plumbers i rang.
They say the same thing.
It looks like a new cylinder for me.
i have a guy comming around today.
i don,t think i will get much change out of
£500.
thanks for your advice.
steve

 

[Hamiltonandy]

£500 just to change a tank. Wow. Simple job like that!. I would get local plumbing supplier to estimate for tank. Should be few hours work just to unscrew old connections, even if seized and fit to new tank. Time consuming if connections are in different locations.
Central heating overflow always overflows into central heating feeder tank.