Set Appliance State:
Mains Power Off
Set Multimeter to AC Volts 
Turn Hot Water Tap On
Remove plastic cover from the ignition control PCB attached to the gas valve
Move the leads that run to the ignition board so that the four gas valve
terminals are visible (Do not disconnect any leads)
Selector switch to OFF position
CH temperature selector to MIN
DHW temperature selector to MAX
Move the leads that run to the ignition board so that the four gas valve
terminals are visible (Do not disconnect any leads)
Selector switch to OFF position
CH temperature selector to MIN
DHW temperature selector to MAX
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Selector switch to hot water position.
Allow ignition sequence to commence.
Measure voltage across the live connection of EV1, (the terminal at the bottom of the four terminals made visible by moving the leads), and connection 2 neutral (blue wire) on the ignition PCB.
Note:
Connections are numbered from the top (1) to the bottom (12).
Allow ignition sequence to commence.
Measure voltage across the live connection of EV1, (the terminal at the bottom of the four terminals made visible by moving the leads), and connection 2 neutral (blue wire) on the ignition PCB.
Note:
Connections are numbered from the top (1) to the bottom (12).
Isolate as per TOPs P4
and refit as necessary