Set Appliance State:
Set Multimeter to DC Volts 
Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
Expose PCB by removing plastic control box cover.
Mains Isolator Switch (ON/OFF Switch) in ON position
Selector Switch in DHW Summer position
Hot Water Temperature Control set to Maximum
Remove the two grey wires (1) from the Modureg Solenoid and make safe
Expose PCB by removing plastic control box cover.
Mains Isolator Switch (ON/OFF Switch) in ON position
Selector Switch in DHW Summer position
Hot Water Temperature Control set to Maximum
Remove the two grey wires (1) from the Modureg Solenoid and make safe
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
With burner alight, measure DC voltage across connections D7 (Grey wire) and D8 (Grey wire) on PCB.
Voltage should be greater than 24V DC.
Mains Power OFF.
Reconnect wires after test.
Voltage should be greater than 24V DC.
Mains Power OFF.
Reconnect wires after test.
Isolate as per TOPs P4
and refit as necessary