Medium
1 P1 on Ariston E-Combi One

Your boiler has detected that water is not moving around your heating system fast enough, often due to trapped air or a closed valve.

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

Insuffi cient circulation indication

From this model's manual
Verified against the Ariston/Ariston E Combi One 24 installation & service manual, page 38.
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 that all radiator valves throughout your home are fully openCheck your boiler display to ensure the system pressure is between 1 and 1.5 barBleed all radiators in the house to release any trapped airReset the boiler using the reset button on the control panel

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Related fault codes

1P2View →1P3View →

All 53 fault codes on the E-Combi One

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

1 011 031 041 051 061 071 091 101 121 141 161 181 P21 P31 P42 053 013 023 033 043 053 063 073 P94 114 124 135 015 025 045 P15 P25 P36 106 127 017 027 037 117 127 137 227 237 5010121314108591INSUFFICIENT WATERSafety Shut-off

Related guides you might find useful

How to bleed a radiator

Quarter turn on the valve, wait for water, then check the boiler pressure.

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Hot water works but heating does not

On a combi it is usually the diverter valve. On a system boiler, the motorised valve.

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What pressure should my boiler be?

1 to 1.5 bar when cold on most UK boilers, from the manuals.

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