How much does it cost to fix Glow-worm error code F.72?

Typical repair cost for the Glow-worm F.72 fault is £120-240 including labour.

F.72 High

Glow-worm F.72 Fault Code

Q: What does the Glow-worm F.72 fault code mean?

Your boiler has detected that its flow and return sensors are providing conflicting readings, which prevents it from heating your home safely.

Also written as F72 — same fault.

The Glow-worm F.72 fault code means: your boiler has detected that its flow and return sensors are providing conflicting readings, which prevents it from heating your home safely.. It appears on 6 Glow-worm models in our database.

Technical description: Deviation in the water pressure sensor/return temperature sensor

What causes the Glow-worm F.72 fault?

This fault occurs when the boiler detects a permanent difference between the temperature readings on the flow and return pipes. It usually happens because one of the internal sensors has failed, or because there is a physical blockage or pump issue preventing water from circulating evenly through the system.

Typical repair cost £120-240 (including labour)

Engineer required

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

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Glow-worm models that show the F.72 fault code

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

Source

Glow-worm F.72 fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.

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