How much does it cost to fix Heatline error code Overheat LED flashing?

Typical repair cost for the Heatline Overheat LED flashing fault is £120-250 including labour.

Overheat LED flashing High

Heatline Overheat LED flashing Fault Code

Q: What does the Heatline Overheat LED flashing fault code mean?

Your boiler has switched itself off because it has detected an unsafe temperature level, likely due to a blockage in the water flow or a faulty temperature sensor.

Also written as OVERHEATLEDFLASHING — same fault.

The Heatline Overheat LED flashing fault code means: your boiler has switched itself off because it has detected an unsafe temperature level, likely due to a blockage in the water flow or a faulty temperature sensor.. It appears on 2 Heatline models in our database.

Technical description: Fault on overheat thermostat

Typical repair cost £120-250 (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 Overheat LED flashing fault code

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

Source

Heatline Overheat LED flashing 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