BoilerFaultCodesThe system has detected that the wrong type of temperature sensor has been installed for your solar heating circuit.
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: Cylinder temperature sensor type used as collector temperature sensor (T1)
What causes this fault?
This fault happens because the control system has detected an electrical signal that doesn't match the expected part for your solar panels. It usually occurs if the wrong type of probe was fitted during a repair or if the internal resistor in the sensor has failed, causing it to send the wrong data to the boiler. As a result, the solar thermal system cannot accurately monitor the temperature at the roof panels.
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 51123 — no call-out fees, no surprises.
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