Triton electric shower - no water

[bazjaq]

My son's Triton W9500S has stopped working. At first I thought it might be the solenoid and checked the resistance, it reads 3.75 ohms. I believe that means the solenoid is ok. There are 2 indicator lights on the front of the shower, power and low pressure, neither of these is lit. I am not sure what I am supposed to check now or how to do it. I have an analogue multimeter.