BoilerFaultCodes.com
b5 Low

Your boiler is simply taking a short, scheduled break because the water in your radiators has already reached the temperature set on the dial.

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.

Technical description: Control stop from 3 till 10 minutes: appears if the set flow temperature (t1) has already been reached and the heating demand still exists.

DIY fix possible

Check if your thermostat or boiler temperature dial is set to a comfortable levelEnsure your radiator valves are fully open to allow heat to circulateWait 10 minutes to see if the boiler restarts automatically once the water temperature drops

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