Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Remove plastic top cover from the Gas Valve
(held by one screw top R/H corner of the cover).
ON/OFF Switch in the ON Position
CH Temp Selector in Minimum position
DHW Temp Selector in Mid position
Mode Selector Switch in Heat and Hot water position
Set DHW Flow Rate at the tap to approximately 5 ltrs/min
(held by one screw top R/H corner of the cover).
ON/OFF Switch in the ON Position
CH Temp Selector in Minimum position
DHW Temp Selector in Mid position
Mode Selector Switch in Heat and Hot water position
Set DHW Flow Rate at the tap to approximately 5 ltrs/min
Gas On
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Measure Voltage across the terminals of the Modulating Solenoid.
Allow the boiler to heat the DHW.
Does the Voltage reduce as the temperature of the DHW increases?
(Voltage should reduce to maintain DHW at approximately 55-60°C)
Allow the boiler to heat the DHW.
Does the Voltage reduce as the temperature of the DHW increases?
(Voltage should reduce to maintain DHW at approximately 55-60°C)
Isolate as per TOPs P4
and refit as necessary