High
F.01 on Glow-worm Easicom3 System

Your boiler has lost communication with a sensor that monitors the temperature of water returning to the system, causing the unit to stop working as a safety precaution.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Fault: Return temperaturesensor - NTC plug not plugged in or has come loose, multiple plug on the PCB not plugged incorrectly, interruption in cable harness, NTC sensor defective

From this model's manual
Verified against the Glow Worm Easicom3 System installation & service manual, page 42.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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