How much does it cost to fix Ideal error code E 37?

Typical repair cost for the Ideal E 37 fault is £120-220 including labour.

E 37 High

Ideal E 37 Fault Code

Q: What does the Ideal E 37 fault code mean?

Your boiler has lost its connection to a sensor responsible for monitoring the temperature of the water returning to the system, causing the unit to stop working as a safety precaution.

Also written as E37 — same fault.

The Ideal E 37 fault code means: your boiler has lost its connection to a sensor responsible for monitoring the temperature of the water returning to the system, causing the unit to stop working as a safety precaution.. It appears on 1 Ideal model in our database.

Technical description: Return thermistor open circuit

Typical repair cost £120-220 (including labour)

Engineer required

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

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Ideal models that show the E 37 fault code

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

Imax W Repair: £120-220

Source

Ideal E 37 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