Set Appliance State:
Mains Power Off
Set Multimeter to DC Volts 
Turn Hot Water Tap On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow ignition sequence to commence and burner to ignite and establish.
Measure the voltage between the two wires at the gas valve modureg.
Expected voltage approximately 12V DC (18V for LPG appliances).
Note:
Voltage may read as negative.
Measure the voltage between the two wires at the gas valve modureg.
Expected voltage approximately 12V DC (18V for LPG appliances).
Note:
Voltage may read as negative.
Isolate as per TOPs P4
and refit as necessary