5 pulses High

Worcester Bosch 5 pulses Fault Code

Also written as 5PULSES — same fault.

The Worcester Bosch 5 pulses fault code means: your boiler has been left in a manual testing mode after a recent service or inspection, which is preventing it from running normally.. It appears on 13 Worcester Bosch models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Check service mode switch is in max position

What causes the Worcester Bosch 5 pulses fault?

This fault occurs when the boiler is accidentally left in its manual override or 'chimney sweep' mode, which is normally used by engineers to test the system at full power. Because this mode is only meant for short-term testing, the boiler will prevent normal operation to protect the internal components from overheating. It most commonly happens when an engineer forgets to flick the internal service switch back to its normal position after a maintenance visit.

Typical repair cost £0-80 (including labour)

DIY fix possible

Locate the internal control dials on the front of the boilerIdentify the service 'chimney sweep' switch or adjustment dialEnsure any test switches are turned back to the 'off' or 'normal' position rather than 'max'Reset the boiler by pressing the reset button for five seconds

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Worcester Bosch models that show the 5 pulses fault code

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

Source

Worcester Bosch 5 pulses 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