I have a Baxi Combi 80e and after bleeding my radiators it was showing me a fault on the pump or low pressure, what I did after was open the tap on the pump and let all the water out.
Now I am having a problem with the system pressure it says that the normal operating pressure is between 1 and 2.5.
The problem that I am having is that the pressure is on the 0, when I open the tap below the boiler it goes up, but after 30minutes it comes back down to 0 again.
Do I need to call a plumber or can anyone advise me?

luis, February 2009

Check your pressure release valve for passing water, check your expansion vessel has correct pressure and also check for leaks

STE, February 2009

Maybe there's "new" air in the system because you emptied it out after bleeding the radiators? Try bleeding then topping up after you bleed rather than empting first. Also check all the bleed valves are totally closed on the radiators, and also check near the hot water tank for a bleed valve (probably in loft or cupboard) We had a similar issue on another make of boiler where pressure would drop over time (a few days) but gradually with tightening things up and topping up the pressure from the tap at the boiler, it seems to have cleared. I think our system was suffering from not having been used constantly. If your system is off for periods of time, try running it more regularly? Otherwise it sounds like a leak/burst somewhere.

Drew, February 2009