High Lockout
E07 on Potterton Powermax HE

Your boiler is unable to read the hot water temperature correctly, meaning you likely have no hot water or unstable water temperatures.

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

DHW sensor open circuit. Check cable/connections not damaged. Renew DHW cable/sensor assy. Part No. 5106290

What causes this fault?

This fault occurs when the boiler's internal computer loses communication with the sensor responsible for measuring your tap water temperature. This is typically caused by the sensor's internal components failing due to age or the electrical wiring becoming brittle and snapping over time. Because the boiler no longer knows how hot the water is, it shuts down the hot water system as a safety precaution.

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

E08View →E09View →

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