How much does it cost to fix Heatline error code F20?

Typical repair cost for the Heatline F20 fault is £120-250 including labour.

F20 High

Heatline F20 Fault Code

Q: What does the Heatline F20 fault code mean?

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage to its internal components.

The Heatline F20 fault code means: your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage to its internal components.. It appears on 8 Heatline models in our database.

Technical description: Overheating fault

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 F20 fault code

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

Capriz Plus Repair: £120-250
Centurion 25 Repair: £120-250
Compact 24 Repair: £120-250
Compact 30 Repair: £120-250
Monza Repair: £120-£250
Solaris Repair: £120-250
Vizo 24 Repair: £120-250
Vizo 28 Repair: £120-250

Source

Heatline F20 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