i have seen the same problem 2 days ago, a temp fix that i done was to remove the two pressure switches and operate the stainless pins when running the hot water.you need to remove the front boiler cover and remove the 2 screws holding the main panel, this will then fold down. the pressure swiches are the black plastic box's on the left on the brass diverter valve. do all this with the power switched OFF. refit the switches and switch on and run. if you notice any signs of water passing around the stainless pins then the diaphrams are damaged and will need replacing. the pressure switches will also not operate correctly if there is any air trapped in the system. another quick check is to see if the 'tap' indicator lights on the boiler panel when the hot tap is running and the power on, if so then the pressure swiches are prob. ok and the divertor valve maybe the problem. if you know a good electrician then he should be able to check the pressure swich operation from the black connector on the right of the boiler pcb. if all the above ok then the pcb is faulty.
remember to swich the power off before dropping the front panel, if you feel that you maybe out of your depth then don't touch it, get a pro to check it out. most boiler engineers are quite good, but the odd few have no idea with electrical fault finding on these systems. maybe try baxi direct for a engineer.
the_fixer
August 2007