High
Lock-out on Heatline Capriz 25/28

Your boiler has shut down to protect itself, likely because it got too hot or failed to light the gas flame.

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.

What the manual says

Manufacturer manual

Activated by overheat thermostat or ignition failure. Boiler has to be manually re-set by switching the control knob off (for 15 seconds) and on again.

From this model's manual
Verified against the Heatline Capriz 28 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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