How much does it cost to fix Heatline error code E15?

Typical repair cost for the Heatline E15 fault is £150-250 including labour.

E15 High

Heatline E15 Fault Code

Q: What does the Heatline E15 fault code mean?

Your boiler has detected that the water temperature is significantly different between the start and end of its heating circuit, which usually means there is a problem with the internal sensors or the flow of water.

The Heatline E15 fault code means: your boiler has detected that the water temperature is significantly different between the start and end of its heating circuit, which usually means there is a problem with the internal sensors or the flow of water.. It appears on 2 Heatline models in our database.

Technical description: Sensor difference fault (Flow/Return)

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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Heatline models that show the E15 fault code

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

Source

Heatline E15 fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.

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