BoilerFaultCodesYour boiler has detected a technical fault with a sensor in your solar heating system, which may affect its ability to heat your water using solar energy.
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: Control mode - Solar: Sensor S3 shorted out
What causes this fault?
This fault occurs when the temperature sensor responsible for monitoring your solar hot water cylinder develops a short circuit, preventing the boiler from receiving accurate data. The most common reason is water ingress or heat damage to the sensor probe itself, but it can also be caused by physical damage or a pinch in the electrical cable connecting the sensor to the control unit.
This fault is more common during the summer months when solar thermal systems are under peak thermal stress and high temperatures are most likely to degrade older sensor components.
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 93 — no call-out fees, no surprises.
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