BoilerFaultCodesYour boiler has lost connection with the sensor that measures the temperature outside, meaning it may not heat your home as efficiently as usual.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Wiring or resistance issues with the external outside temperature sensor.
What causes this fault?
This fault occurs when the boiler can no longer communicate with the small sensor box located on your external wall. The most common reasons are moisture entering the sensor casing causing corrosion, or a break in the thin communication wire leading back to the boiler.
This fault is more frequent during autumn and winter when increased rainfall and freezing temperatures can damage exposed external wiring or sensor seals.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like Outside Sensor Fault — no call-out fees, no surprises.
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