High
110 on Baxi 818 System

Your boiler has likely overheated, causing a safety sensor to shut the system down to prevent damage.

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

Safety thermostat operated or faulty. Check for and correct any system faults. Allow to cool. Continuity across thermostat terminals more than 1.5 ohm. If still flashing replace PCB.

From this model's manual
Verified against the Baxi 818 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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