Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove diverter valve actuator from diverter valve assembly
(this can be done without draining boiler)
Disconnect electrical connection to the actuator

Measurement:

Inspect the following diverter valve components for signs of water:
  • Actuator spindle and electrical connections
  • Actuator electrical connector
  • Diverter valve stuffing box