How much does it cost to fix Heatline error code Flashing 30?

Typical repair cost for the Heatline Flashing 30 fault is £120-220 including labour.

Flashing 30 High

Heatline Flashing 30 Fault Code

Q: What does the Heatline Flashing 30 fault code mean?

Your boiler has lost the ability to accurately measure the temperature of the water being sent to your radiators, so it has purposefully shut down to prevent overheating.

Also written as FLASHING30 — same fault.

The Heatline Flashing 30 fault code means: your boiler has lost the ability to accurately measure the temperature of the water being sent to your radiators, so it has purposefully shut down to prevent overheating.. It appears on 2 Heatline models in our database.

Technical description: Fault on CH sensor

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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Heatline models that show the Flashing 30 fault code

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

Source

Heatline Flashing 30 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