Set Appliance State:
Mains Power Off
Set Multimeter to AC Volts 
CH Demand
Boiler Thermal Store must be at MAXIMUM TEMPERATURE, to ensure this, run the boiler until the Green Neon extinguishes then:
Models with Programmer:
Rocker Switch to Timed, Programmer C/H demand to ON.
Models without Programmer: Central Heating Switch to ON.
Models with Programmer:
Rocker Switch to Timed, Programmer C/H demand to ON.
Models without Programmer: Central Heating Switch to ON.
Gas On
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Measure Mains Voltage across Connection 6
(on the 12 way Terminal Block) and the Main
Appliance Neutral Connection.
(on the 12 way Terminal Block) and the Main
Appliance Neutral Connection.
Isolate as per TOPs P4
and refit as necessary