F.71
FAULT CODE
Vaillant
Flow Temperature Sensor Constant Value
Medium Severity
Engineer Required
The flow temperature sensor is sending a fixed, constant reading rather than a variable one, suggesting the sensor has failed or its connection is intermittent.
Step-by-Step Fix Guide
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Step 1 Engineer only
Call a Gas Safe engineer to test and replace the flow NTC sensor
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.