E:04.12 Emergency

Baxi E:04.12 Fault Code

Also written as E0412 — same fault.

The Baxi E:04.12 fault code means: your boiler has detected a flame inside when it should be turned off, so it has purposefully shut down to keep you safe.. It appears on 8 Baxi models in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: False flame signal
Typical repair cost £150-300 (including labour)

Engineer required

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

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like E:04.12: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Baxi models that show the E:04.12 fault code

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

Source

Baxi E:04.12 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 7 July 2026