E 15 Low

Chaffoteaux E 15 Fault Code

Also written as E15 — same fault.

The Chaffoteaux E 15 fault code means: your boiler is struggling to read the outdoor temperature correctly because the cable connected to the external weather sensor is likely damaged or loose.. It appears on 2 Chaffoteaux models 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: Outdoor sensor open circuit (where fitted)
Typical repair cost £100-180 (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 15 fault code

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

Source

Chaffoteaux E 15 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 7 July 2026