Low
S.34 on British Gas 330+

Your boiler has sensed very cold temperatures and has automatically turned on its built-in safety 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 (Priority 4). Temperature below 8O C - check thermistor connection if this is not true.

From this model's manual
Verified against the British Gas 330 installation & service manual, page 47.
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 home heating is turned on or the thermostat is set to a reasonable temperature.Ensure any visible condensate pipes leading outside are not frozen or blocked.Wait for the boiler to finish its warming cycle; the code should disappear once the internal temperature rises.

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