F.11
Vaillant fault code
Vaillant F.11: return temperature sensor short circuit
Engineer only
Vaillant describes F.11 on ecoTEC plus boilers as: return temperature sensor short circuit. Possible causes Vaillant lists, for an engineer to check: nTC defective, short circuit in cable harness, cable to casing.
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.