F76 Safety cut-out — Primary heat exchanger thermal link defective

What does F76 mean?

The safety cut-out (thermal link) in the primary heat exchanger is defective, meaning its feedback doesn't match the gas valve feedback.

• Safety cut-out in the primary heat exchanger is defective (thermal link)
• Thermal cut-out feedback does not match gas valve feedback
• Wiring harness continuity issue

Click steps to track your progress.

1. 1

   Disconnect the wires from the thermal fuse and try linking them out (requires a qualified person).

2. 2

   If the boiler fires up after linking out, the thermal fuse is faulty and needs replacement.

3. 3

   If it doesn't fire up, check continuity down the wiring harness (requires specialist tools).

4. 4

   If all checks fail, the PCB may be faulty (contact a technician).