E 34 Emergency

Chaffoteaux E 34 Fault Code

Also written as E34 — same fault.

The Chaffoteaux E 34 fault code means: your boiler has lost its connection to a safety sensor that monitors the exhaust fumes, causing it to shut down to prevent unsafe operation.. It appears on 2 Chaffoteaux 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: Flue pipe sensor open circuit
Typical repair cost £150-250 (including labour)

Engineer required

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

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Chaffoteaux models that show the E 34 fault code

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

Source

Chaffoteaux E 34 fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026