wrote in message
...
hi there
I have a pressure prob with a sealed gfch system.

The pressure shoots up and down - according to the FAQ, this prob
means that the expansion chamber has failed, but when I check the
chamber, there is no water coming out of the valve - only air. Air
pressure is approx 10/11 PSI. I keep topping up water, but there is no
apparent leak...

It could be that there's not *enough* air in your expansion vessel. If it
has a diaphragm you won't see water coming out the air top up valve unless
the diaphragm has failed. If there is too little air then the expansion
vessel might not have enough capacity to absorb the water expansion in the
system.

Tim

Any ideas?