Low
FLASHING F on Gledhill GB35C

Your boiler has detected very cold temperatures and has automatically turned on its high-level frost protection mode to prevent the internal pipes from freezing.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Frost Protection active - Level 2

From this model's manual
Verified against the Gledhill Gb35c installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Ensure the boiler's power remains switched onOpen any radiator valves in cold areas of the home to allow warm water to circulateCheck that the condensate pipe outside is not frozen or blockedWait for the boiler to finish its heating cycle, after which the code should disappear automatically

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