High Lockout
Float switch on Ideal Concord CXC 48 116

Your boiler has detected that the water levels inside the system are incorrect, or the sensor that monitors the water level is faulty.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Float switch fault detected by diagnostic feature.

What causes this fault?

This fault occurs when the internal water level sensor fails to signal that the boiler has sufficient water to operate safely. The most common reasons are a physical blockage or debris interfering with the float's movement, or an electrical failure within the sensor itself that prevents it from communicating with the main control board.

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.

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Related fault codes

No FlowView →OverheatView →

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