On Feb 10, 2:01*pm, "John" wrote:
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...

Any ideas?

It will vary - describe the range of "shooting up and down"


I fill the boiler to approx 1.25 bar. Once the heat comes on, the
pressure shoots up to 3 bar. Once the heat comes off it settles back.
While the boiler continues to operate, the pressure will drop slowly
to 0 and then I have to top-up again.

All very painful when i have to get up at 5am to top up...

thanks for your quick response