Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the cover from the pump

Measurement:

Test 1:
Measure the resistance between the live and neutral connections inside the pump.
Expect approximately 160 ohms or greater.
Test 2:
Measure the resistance between the live and earth connections inside the pump.
Expect a resistance greater than 1 Mohm.
Are the resistances measured as expected?