F.10
FAULT CODE
Vaillant
Flow NTC Short Circuit
High Severity
Engineer Required
The flow temperature sensor has developed a short circuit. This prevents the boiler from accurately reading flow temperature, triggering a safety shutdown.
Step-by-Step Fix Guide
-
Step 1
Turn off the boiler
-
Step 2 Engineer only
Contact a Gas Safe engineer — the flow NTC and associated wiring will need inspection and likely replacement
Gas Safe Reminder
Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.