Set Appliance State:
Set Multimeter to DC Volts 
Turn Hot Water Tap On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Reset boiler as necessary. Activate TEST mode by holding the heating buttons together for 5 seconds.
Test 1:
Press the DHW "-" button to set boiler to minimum mode.
Measure the DC voltage between the between the pin 2 (brown) and pin 4 (blue) leads at the gas valve
Voltage should be approximately 9V DC.
Test 2:
Press the DHW "+" button to set boiler to maximum mode.
Measure the DC voltage between the between the pin 2 (brown) and pin 4 (blue) leads at the gas valve
Voltage should have increased to approximately 10V DC.
Note:
1. Boiler may enter lockout during test, reset as necessary until test is complete.
2. Negative voltage may be measured, this is ok as long as voltage is still approximately -9/10V DC.
3. To deactivate TEST mode hold the heating buttons together for 5 seconds.
Test 1:
Press the DHW "-" button to set boiler to minimum mode.
Measure the DC voltage between the between the pin 2 (brown) and pin 4 (blue) leads at the gas valve
Voltage should be approximately 9V DC.
Test 2:
Press the DHW "+" button to set boiler to maximum mode.
Measure the DC voltage between the between the pin 2 (brown) and pin 4 (blue) leads at the gas valve
Voltage should have increased to approximately 10V DC.
Note:
1. Boiler may enter lockout during test, reset as necessary until test is complete.
2. Negative voltage may be measured, this is ok as long as voltage is still approximately -9/10V DC.
3. To deactivate TEST mode hold the heating buttons together for 5 seconds.
Isolate as per TOPs P4
and refit as necessary