Leaking Overflow

[nstewart30]

Hi there, I've currently bought a new property (about a 10 year old house) I am having problems with a leaking overflow. Going into the loft I have identified 2 tanks with 2 overflows coming off these. The larger of the 2 tanks appears to be over full when the overflow leaks. Initially I thought this was to do with the ball valve mechanism rubber washer, like a toilet cistern, being perished. But upon inspection this seems ok. It tends to overflow when the boiler has been on heating the water. I went up their this morning as the overflow was going again and there is a return pipe from the hot water jacket sending water back to the water storage tank. Could anyone help me by explaining why this is happening.

Thanks

 

[oph]

Sounds as if your water too hot hence water pumping over. However impossible to know for sure

 

[TicklyT]

It is normal practise to set the float valve in the cold water storage tank to cut off at least a couple of inches below the overflow level to allow for expansion when water is heated. The water level in the small feed and expansion tank is usually set only a couple of inches above the outlet pipe to allow maximum room for expansion.

Water running from the vent pipe is indicative of other problems. The vent should remain dry in normal operation. That water has to be coming from somewhere. Do you have any mixer taps or shower valves in the house?

Mixer taps with mains pressure cold supplies and gravity fed hot sometimes allow cold water to backfeed into the hot system causing an overflow. Try closing the isolating valves for the mixers to identify which one may be causing the problem.

 

[nstewart30]

No there are no mixer taps in the house. I think that it could be coming from the Jacket when the water is being heated by the boiler. Is their something that can fail on the hot water jacket that would cause this to happen?

 

[bluebaron]

Tickly T,

I think that i may have the problem you describe, The water overflows during the night and leaves a large puddle on my deck. I had a new en-suite fitted recently with mains water taps/shower and gravity Hot feeds.

Obviously i do not want to isolate these taps permanatly. What would be the solution to this?