Set Appliance State:
Gas Off
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
CH Demand
CH temperature control to max
ON/OFF switch ON
ON/OFF switch ON
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow fan to start.
After approximately 2 seconds measure for dc voltage across connections 18 (red) and 9 (blue) on the connector X20.
Expected voltage approx 20vdc at first, then reduces to approx 15vdc.
Voltage will only be present for approx 5 seconds during the ignition phase, the appliance will try to ignite 5 times before going to lockout.
Note:
Lockout may occur after 5 attempts to ignite.
Reset boiler if required.
After approximately 2 seconds measure for dc voltage across connections 18 (red) and 9 (blue) on the connector X20.
Expected voltage approx 20vdc at first, then reduces to approx 15vdc.
Voltage will only be present for approx 5 seconds during the ignition phase, the appliance will try to ignite 5 times before going to lockout.
Note:
Lockout may occur after 5 attempts to ignite.
Reset boiler if required.
Isolate as per TOPs P4
and refit as necessary