Medium
S.53 on Glow-worm Essential

Your boiler has temporarily stopped because it detected an imbalance in water temperature or pressure, often caused by the system struggling to circulate water efficiently.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Productinwaitingperiod/operationblockfunctionduetolowwaterpressure(flow/returnspreadtoolarge)

Shared across the Essential 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

Check your boiler's pressure gauge and ensure it is between 1 and 1.5 barIf the pressure is low, use your filling loop to top it up to the correct levelCheck that all your radiator valves are fully open to allow water to circulate properly

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Related fault codes

F.22View →F.24View →

All 83 fault codes on the Essential

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

F.00F.01F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.33F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.83F.84F.85F.86F.87F.88F.89F22S.0S.01S.02S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.33S.34S.39S.41S.42S.46S.54S.88S.91S.96S.97S.98S.99S.108S.109

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