High
LA on Ideal Mexico HE

Your boiler has become too hot and has shut itself down for safety purposes.

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

OVERHEAT ERROR

From this model's manual
Verified against the Ideal/Ideal Mexico 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.

What causes this fault?

This fault occurs when the water inside the boiler exceeds a safe temperature limit, triggering an emergency shutdown to prevent damage. It is usually caused by a lack of water flow, often due to a pump failure or a blockage within the pipework that prevents heat from being carried away from the unit. In some cases, a build-up of limescale or sludge acts as an insulator, causing the internal components to get too hot too quickly.

This fault is frequently seen at the start of autumn when heating systems are turned back on after a long summer break, as internal pump components may have seized from disuse.

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

All 13 fault codes on the Mexico HE

Seeing a different code? Every code this model can display, in one place.

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