You have a blockage on the pressure sensor... Very common on this model.
You could drain the appliance, unscrew the low water pressure switch and force a small (Electrical) screwdriver into the hole on the pipe to clear the blockage and fix the problem yourself.
As a temporary fix for overnight you could swap one of the wires onto the spare spade, reversing the signal and "tricking" the boiler - This can be classed as overriding a safety device and is illegal and should not be done unless extreme circumstances are present.
The pressure switch can be identified by having two wires connected to it, and three terminals available for use. It's white topped and has a silver bead round the edges. You need to remove the white case and hinge open the control panel door.
As this is classed as "Working on the Appliance" this fault should only be undertaken by a competant person.
ThermGas, January 2007
