Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
CH Demand
Gain access to terminal block

Measurement:

Measure the resistance (continuity) across the timer/programmer harness.
Connections are;
  • X1 connector pin 2 to pin 2 on terminal block.
  • X1 connector pin 3 to pin 1 on terminal block.
    Expected resistance is continuity (zero resistance).
    Note.
    Ensure a good connection is made or misdiagnosis will occur.