Expansion tank overflowing

[MURFIA]

Hi,
My expanstion tank keeps overflowing. Its in the loft next to the cold water tank. The cylinder is on the 1st floor. I have bent the ball valve down, but I dont think the water is comming from the main feed.
Guessing it may be the cylinder coil.
Any help would be appriciated.

 

[seco services]

Is the water in the f/e tank warm/hot ?
Is it only when heating or hw on it overflows ?

Need more info.

 

[MURFIA]

The hot water and heating is on and the water in the tank is warm.
The water in the tank is cold when off.
Its overflowing when the heating is off.
Its been doing it for the last 3 weeks, but I have only got round to looking at it today. So dont know if it does it when its hot.
I removed alot of water when cold, down to valve level. I repeated this when I turned the heating on.
I did replace a rad 3 weeks ago and blead the system, but I think theres still air in it.
I will now monitor the tank water levels.

 

[Dan Robinson]

Is the F&E above or below the cold water storage cistern?

Could be your cylinder coil is goosed.

 

[MURFIA]

Its in the loft, next to the cold water tank. On the same level.

 

[Dan Robinson]

So the F&E water level is below that of your CWS cistern.

I think we found your problem.

 

[MURFIA]

Bugger. I'm guessing thats why the system is noisy i.e banging sounds. and I guess it will cost alot more to heat the system?