Low
S.02 on Heatline Monza

Your boiler is currently checking the water circulation pump before it fires up, which is a standard part of its startup process.

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

Pre-run pump

Shared across the Monza range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s 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

No action required; this is a normal status messageWait for the boiler to complete its startup sequenceMonitor the display to see if it progresses to a heating or hot water mode

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Related fault codes

S.03View →S.06View →

All 111 fault codes on the Monza

Seeing a different code? Every code this model can display, in one place.

d.00d.01d.02d.08d.09d.10d.16d.17d.18d.20d.22d.23d.33d.34d.35d.36d.40d.41d.44d.67d.68d.69d.71d.80d.81d.82d.83d.85d.93d.94d.96ErrF00F01F10F11F20F22F23F24F26F27F28F29F32F49F61F62F63F64F65F67F68F70F71F72F73F74F76F77F83F84F85F86P.01P.02P.03P.05P.06P.07S.00S.01S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.35S.36S.37S.41S.53S.54S.58S.90S.92S.95S.96S.97S.98

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