BoilerFaultCodesTechnical description
Pressure Sensor Error (UK) – Heating flow switch error (Ireland)
What causes this fault?
This fault occurs when the boiler detects a mismatch between the internal pump running and the actual movement of water through the system. The most common reason is a faulty pressure sensor or flow switch that is sending incorrect data to the control board, but it can also be caused by a blockage or trapped air preventing water from circulating freely.
This issue is often seen in autumn when the heating is turned on for the first time after summer, as internal parts can sometimes seize or stick during long periods of inactivity.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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