Vaillant Boiler F72 Fault – Error Code Guide

The Vaillant F72 error code affects the Ecotec Pro, Ecotec Plus and Ecotec Exclusive models of Vaillant boiler. It means that there is a fault with the flow and return thermistors.

Either the parts themselves are faulty, or communication between the thermistors and PCB is inconsistent due to faulty or damaged wiring.

If the thermistors are faulty, then these will need replacing but if not, an engineer should be able to resolve this issue without needing to replace any parts.