i have just drained the system to move a rad, something i have done on a couple of previous times , i refilled the combi to about 1.2 when off when i turned the boiler on the pressure went up to 2.5 then up to 3 on the pressure gauge. i tried to drain the water out to drop some pressure back but the water came out at a trickle , and gauge never dropped the pressure one bit . i have since drained some more water and still no change in the pressure reading . the boiler is just short of three years old, and a worcester bosch 24cdi. i would very pleased with any help . regards simon johns

simon johns, January 2008

Hi. Have you turned off and closed the shut off valve which feeds the boiler with cold water from the water mains as you drain some of the water off from the system? If not, as you drain the system it will simply be refilled automatically from the mains until it reaches the mains pressure which will be around 2 or 3 bar depending on your water supplier.

Alf, March 2008