Set Appliance State:
Mains Power Off
Gas Off
Set Multimeter to mVolts DC 
Selector Switch in mid (0) position
Light Pilot and keep Ignition button pressed in to prevent
the pilot from going out.
Light Pilot and keep Ignition button pressed in to prevent
the pilot from going out.
Gas On
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Connect one lead to the pipe work and the other to one of the
High Limit Thermostat terminals. Voltage measured should
be greater than 8 mV DC.
Repeat the measurement but this time use the other terminal of the High Limit Thermostat. Once again the voltage measured should be greater than 8 mV DC.
NOTE!
Care should be taken to ensure a good contact is established between the test probe and the terminals, lacquer may need to be scratched away.
High Limit Thermostat terminals. Voltage measured should
be greater than 8 mV DC.
Repeat the measurement but this time use the other terminal of the High Limit Thermostat. Once again the voltage measured should be greater than 8 mV DC.
NOTE!
Care should be taken to ensure a good contact is established between the test probe and the terminals, lacquer may need to be scratched away.
Isolate as per TOPs P4
and refit as necessary