Set Appliance State:
Set Multimeter to mVolts DC 
Isolate Mains Power to appliance as per TOPs P4
Selector switch in HW position
System cool - (Overheat stat not operative).
Clip one lead to thermocouple sheath.
Ignite pilot and keep Gas Control knob depressed throughout test.
Pull off R/H wire from interrupter and connect other multimeter lead to terminal.
Selector switch in HW position
System cool - (Overheat stat not operative).
Clip one lead to thermocouple sheath.
Ignite pilot and keep Gas Control knob depressed throughout test.
Pull off R/H wire from interrupter and connect other multimeter lead to terminal.
Gas On
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Measure the voltage.
Expect a voltage of 8 mvdc or greater.
Reconnect wire.
Expect a voltage of 8 mvdc or greater.
Reconnect wire.
Isolate as per TOPs P4
and refit as necessary