E74 High

Warmhaus E74 Fault Code

The Warmhaus E74 fault code means: your boiler has stopped working because it cannot correctly measure the temperature of the water inside the system.. It appears on 1 Warmhaus model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Temperature sensor error.

What causes the Warmhaus E74 fault?

This fault occurs when the boiler's internal computer loses communication with the temperature sensor, meaning it can no longer safely monitor how hot the water is. The most common reason is that the sensor has either worn out or suffered an electrical failure, but it can also be caused by loose or damaged wiring connecting the sensor to the main control board.

Typical repair cost £90-160 (including labour)

Engineer required

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

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Warmhaus models that show the E74 fault code

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

Source

Warmhaus E74 fault code information on this page is sourced and cross-checked against the official Warmhaus service / installation manuals for each affected model.

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