Medium
H.02.09 on Baxi 600 System 2

Your boiler has detected low water flow and has automatically turned on its frost protection mode to prevent the system from seizing or freezing.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Partial stoppage — antifreeze function active

Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s 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

Check that your boiler pressure is between 1.0 and 1.5 barEnsure all radiator valves are fully openCheck the condensate pipe outside for signs of freezing or blockageRestart the boiler using the reset button

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Related fault codes

H.02.04View →E.02.07View →E110View →

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