High
Overheat Lockout on Ideal Icos System

Your boiler has shut down because it is too hot, likely due to low water pressure or a circulation issue within your radiators.

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

Fill System to 1.0 Bar, Vent System, Refill System, Check Pump Spins Freely, Check 240V to Pump

From this model's manual
Verified against the Ideal Icos System 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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