Low
P.04 on Glow-worm Compact

Your boiler has been accidentally switched into a testing mode used by engineers to check emissions, rather than a system fault.

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

Chimney sweep function

From this model's manual
Verified against the Glow Worm Compact installation & service manual, page 48.
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

Locate the reset button or the Mode button on your boiler control panel.Press and hold the button for 3 to 5 seconds to exit the test mode.The boiler display should return to showing the current temperature or a standard standby icon.

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