E18 Low

Baxi E18 Fault Code

The Baxi E18 fault code means: your boiler is currently topping itself up with water automatically and is simply waiting for the process to complete before it resumes normal heating.. It appears on 1 Baxi model in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Automatic filling system in operation
Typical repair cost £0-£100 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Baxi models that show the E18 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi E18 fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026