expansion tank overflow leaking

[jjj]

Hi, I have a potterton floor standing boiler. I have noticed the f + e tank overflow is dripping and after checking it in the loft, found that the tank is full. Would it be a blockage that is causing the pumping over or would the boiler stat have gone? I tried a magnet on the "h" where the feed/vent/pump are but it is not sticking to the pipe. Any help would be gratefully received

 

[oilman]

If water is not dripping from the inlet to the tank, then it may be a leak from the coil in the hot water tank. The water would flow from the cold water storage tank to the hot tank, and then get into the heating system. If you turn off all of the taps in the house, is there a constant dripping from the inlet to the cold water storage tank?

 

[jjj]

no, there are no leaks from the cws inlet I turned the pump down and that seems to have stopped it. The cylinder stat is a TRV type and the missus had turned it up to max. Do you reckon this would have had any effect on it pumping over?

 

[oilman]

I can't see about the pumping over, but do you really mean the hot wat temperature control is a radiator TRV?

 

[jjj]

yeah it is not an actual TRV but a similar type control with a capillary strapped to the cylinder. What's the best way, aside from a magnet, to check a blocked cold feed?

 

[oilman]

What's the best way, aside from a magnet, to check a blocked cold feed?

Drain some water from the system and see if the level in the tank goes down About a bucket full will do.

 

[jjj]

Cheers Oilman, that is so obvious I feel like George McFly