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

Typical repair cost for the Ideal E15 fault is £90-160 including labour.

E15 High

Ideal E15 Fault Code

Q: What does the Ideal E15 fault code mean?

Your boiler has detected a problem with the sensor that monitors the temperature of the water coming back into the unit, preventing it from heating correctly.

The Ideal E15 fault code means: your boiler has detected a problem with the sensor that monitors the temperature of the water coming back into the unit, preventing it from heating correctly.. It appears on 6 Ideal models in our database.

Technical description: Return thermistor error

What causes the Ideal E15 fault?

This fault occurs when the boiler's control board stops receiving a reliable signal from the sensor that monitors the temperature of the water returning from your radiators. The most common reason is that the sensor itself has developed an internal electrical failure, or the wiring connecting it to the main computer has become loose or damaged.

Typical repair cost £90-160 (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 →

Ideal models that show the E15 fault code

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

Source

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

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