Low
40 on Worcester Bosch 537i

Your boiler is displaying a status code indicating its current operational output level rather than a fault, meaning the system is likely functioning normally.

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

Heat output 12.1 kW / Heat input 12.2 kW (RD532i L.P.G) or Heat output 14.9 kW / Heat input 15.0 kW (RD537i L.P.G)

From this model's manual
Verified against the Worcester Bosch 537i installation & service manual.
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 if the display is flashing or solid; if solid, the boiler is operating normally.Observe if the boiler proceeds to heat the system after a few moments.If the code persists and the boiler fails to fire, try pressing the Reset button once.

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