Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to DC Volts Set meter to measure DC Volts
Turn Hot Water Tap On
Selector Switch in DHW Summer position
Hot Water Thermostat set to Maximum
Remove diverter valve microswitch from diverter valve
Gas On
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure approximately 24V DC across B4 (Grey) connection on the connector B multi-plug on the PCB and the Pink connection at the
Diverter Valve Micro-switch.