Medium
0.6 bar on Keston R-sm 20 FB

Your boiler is currently reporting that the water pressure inside the system is too low to operate your hot water and heating safely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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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

DHW min working pressure

From this model's manual
Verified against the Keston/Keston R Sm 20 Fb installation & service manual, page 3.
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 filling loop (a flexible metal or plastic pipe) underneath the boiler.Slowly open the valves on the filling loop to allow cold mains water into the system.Watch the pressure gauge on the front of the boiler until it reaches the green zone, typically between 1.0 and 1.5 bar.Close both valves tightly and ensure the filling loop is fully shut off.

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Related fault codes

Low PressureView →F.22View →

All 9 fault codes on the R-sm 20 FB

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

0.5 bar3 bar3A10 barCONDITION 1CONDITION 2CONDITION 3RED LOCKOUT BUTTON

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