Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Gain access to PCB (use Insulation Mat as required)
Disconnect plug from diverter valve and make safe
Disconnect leads from safety sensor and make safe
Disconnect plug from diverter valve and make safe
Disconnect leads from safety sensor and make safe
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
The boiler will immediately enter lockout once power is turned on.
Voltages will only be present for approx 3 seconds from when the boiler is reset.
Multiple resets will be needed to confirm correct voltages.
Test 1:
Measure the voltage across the pins marked 4.1 and 4.4 on X7.
Test 2:
Measure the voltage across the pins marked 4.2 and 4.3 on X7.
Voltage on both tests should be approximately 20V AC
but vary by up to 5V AC constantly during the test.
Voltages Present Voltages Absent or Low on One or Both Tests
Voltages will only be present for approx 3 seconds from when the boiler is reset.
Multiple resets will be needed to confirm correct voltages.
Test 1:
Measure the voltage across the pins marked 4.1 and 4.4 on X7.
Test 2:
Measure the voltage across the pins marked 4.2 and 4.3 on X7.
Voltage on both tests should be approximately 20V AC
but vary by up to 5V AC constantly during the test.
Voltages Present Voltages Absent or Low on One or Both Tests
