F.73
FAULT CODE
Vaillant
Water Pressure Sensor Signal Too Low
High Severity
Engineer Required
The pressure sensor is reading below its expected operating range. This could mean the sensor itself is faulty, or water pressure is extremely low.
Step-by-Step Fix Guide
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Step 1
Check the pressure gauge on the boiler
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Step 2
If pressure is below 1 bar, repressurise using the filling loop
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Step 3 Engineer only
If pressure is correct but the fault persists, the pressure sensor needs replacing — call a Gas Safe engineer
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.