Vaillant Boiler F64 Fault Jun 2026

When your Vaillant boiler displays F64, it has detected a technical problem in its measuring or processing systems. Specifically, it refers to:

: Usually, it comes down to a short circuit in the NTC (Negative Temperature Coefficient) sensors or a complete electronic failure within the Vaillant Main PCB. vaillant boiler f64 fault

Boilers are often located in kitchens or utility rooms where condensation or leaks can occur. If water has dripped onto the PCB or the gas valve wiring harness, it can cause short circuits, leading to a multitude of error codes, including F64. When your Vaillant boiler displays F64, it has