F.64 — Electronics/NTC fault

What does F.64 mean?

A fault has been detected in the boiler's electronics or with one of the NTC sensors (flow or return). This could be due to a short circuit in the sensor or a defect in the main electronic control system.

• Short-circuit in flow or return NTC.
• Electronics defective.

Click steps to track your progress.

1. 1

   Reset the boiler by pressing the reset button.

2. 2

   Power off the boiler, wait a moment, then power it back on.

3. 3

   If the error persists, contact a qualified service technician to inspect the NTC sensors and the main electronics.