F.71
Vaillant fault code
Vaillant F.71: flow temperature sensor fault
Engineer only
Vaillant describes F.71 on ecoTEC plus boilers as: flow temperature sensor fault. Possible causes Vaillant lists, for an engineer to check: flow temperature sensor signalling a constant value: incorrectly positioned or defective.
What you can safely do
There is nothing you can safely do yourself with this one. Leave the boiler off and book an engineer.
Call a Gas Safe engineer if
- Book a Gas Safe registered engineer.
Find a Gas Safe engineer near you
Opens the official Gas Safe Register search.
Applies to: ecoTEC plus. Codes can differ between models, so check your manual.