BoilerFaultCodesYour boiler's outside temperature sensor has developed an electrical fault, meaning the system cannot correctly adjust your heating based on the weather.
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: Shortcut outside sensor temperature
What causes this fault?
This fault occurs when the electrical circuit for the external temperature sensor is completed too easily, usually due to a short circuit in the wiring. The most common reasons are water entering the sensor housing during heavy rain or the wires being pinched or damaged by external work on your home.
This fault is more common in autumn and winter when increased rainfall and freezing temperatures can compromise the sensor's outdoor electrical connections.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 27 — no call-out fees, no surprises.
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