Vaillant Boiler F64 Fault [updated] Jun 2026

If you see the F64 code, you can try resetting the boiler once.

If you are currently without heating and hot water due to this fault, contact a local Gas Safe engineer to diagnose the specific component failure and restore your system safely. vaillant boiler f64 fault

Because the fan, flue, and gas valve are linked for safety, an F64 fault will likely require a . They will: If you see the F64 code, you can