It’s been working flawlessly for the last year, but yesterday it starting behaving as if there is no water in tank: on turning on, the vibe pump makes the loud metallic sort of noise that is made when the tank is empty. After about 1 minute, the Gicar starts beeping.
I’ve opened it up and the pipe from tank to pump is intact.
Does this represent a dead pump, or are there any more checks I need to do before replacing it?
the gicar is designed to alarm and turn off the pump and heating element if the water level in the boiler is not raised to the max level on the sensor within about 25 seconds
if you undo the boiler end of the pressure hose on the outlet side of the pump and direct it into a bowl you can turn the machine on and see if the pump is moving water
if the pump is moving water, then the solenoid is either partially or fully obstructed, but given you say the pump is making unpleasant noises i expect the pump is probably toast