Low
P.04 on Glow-worm Betacom4

Your boiler is currently performing a routine high-power test cycle to ensure it is running efficiently, which will automatically stop after 15 minutes.

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

Maximum output function: If there is a hot water request, the product runs in hot water handling mode and at maximum heat load. If there is no hot water request, the product runs with the heating partial load that is set via diagnostic code d.00 and in heating mode. The function is active for 15 minutes.

From this model's manual
Verified against the Glow Worm Betacom4 installation & service manual, page 31.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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