BoilerFaultCodesTechnical description
External flow sensor out of range or short circuit/External flow sensor measures a temperature outside of normal workingrange.
What causes this fault?
This fault occurs when the internal computer loses reliable communication with the sensor responsible for measuring the temperature of the water leaving the boiler. The most common reason is a physical failure of the sensor’s internal components or a loose connection in the wiring that prevents the system from reading accurate data. Because the boiler no longer knows how hot the water is, it shuts down as a safety precaution to prevent overheating.
This fault may become more apparent during the first cold snap of autumn when the heating system is pushed to operate at higher temperatures for the first time in months.
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.