353 -- Low

Worcester Bosch 353 -- Fault Code

Also written as 353 — same fault.

The Worcester Bosch 353 -- fault code means: your boiler has automatically locked itself out temporarily because it has been running non-stop for too long, but it will reset itself and start working again shortly.. It appears on 8 Worcester Bosch models in our database.

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: Burn temporarily blocked due to no 20 minute continuous OFF time in last 24 hours.

DIY fix possible

Wait patiently for approximately 20 minutesEnsure your thermostat settings are not requesting heat constantlyDo not attempt to open the boiler casing

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Worcester Bosch models that show the 353 -- fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch 353 -- fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026