Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
For access behind the control panel
Release the fixing screw located at the top of the case front panel and lift the panel upwards from its locating pins and then forwards from the boiler. Remove the two fixing screws that secure the control panel and lower the panel.

Measurement:

Disconnect pump live, neutral and earth from the main terminal strip
Check resistances across the disconnected leads resistances should conform to the table below.
Note:
Pump resistance will depend on speed setting.
Test

Leads

Expected Resistance(Ohms)

1.

Pump Live & Pump Neutral

170/500

2.

Pump Live and Earth

Infinity (O L)

3.

Pump Neutral and Earth

Infinity (O L)