Set Appliance State:
Gas Off
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Turn Hot Water Tap On
CH potentiometer set to minimum
Remove the programmer cover or programmer (if fitted)
Remove the programmer cover or programmer (if fitted)
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Allow fan to run and ignition sequence to commence.
On the test pins behind plug ST16 measure the voltages using the
long shrouded probes as below:
Test 1:
Across pins 1 & 2 from the right (brown wires on connector).
Test 2:
Across pins 7 & 8 from the right (purple wires on connector).
Notes:
1. Voltage ( Approx 24 VOLTS DC ) will only be present for approximately 10 seconds and will make 5 attempts at ignition before lockout will occur. This can be reset by pressing and holding the reset button (flashing) for a few seconds.
2. Plug shown for clarity.
On the test pins behind plug ST16 measure the voltages using the
long shrouded probes as below:
Test 1:
Across pins 1 & 2 from the right (brown wires on connector).
Test 2:
Across pins 7 & 8 from the right (purple wires on connector).
Notes:
1. Voltage ( Approx 24 VOLTS DC ) will only be present for approximately 10 seconds and will make 5 attempts at ignition before lockout will occur. This can be reset by pressing and holding the reset button (flashing) for a few seconds.
2. Plug shown for clarity.
Isolate as per TOPs P4
and refit as necessary