High Lockout
E83483 on Potterton Powermax HE

Your boiler's temperature sensors for the hot water storage tank are sending incorrect signals, preventing the system from heating your water correctly.

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

Immersion NTC Sensors

What causes this fault?

This fault occurs when the boiler receives conflicting or impossible temperature readings from the sensors inside your hot water storage tank. The most common reason is that the internal electrical components of the sensor have degraded over time or the wiring connecting them to the main control board has become loose or damaged.

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

E01View →A01View →

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