High
A1 on British Gas RD 430i

Your boiler has sensed that there is not enough water flowing through the system, causing the pump to run without liquid.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Pump has run dry

Shared across the RD 430i 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.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

A3View →E1View →

All 32 fault codes on the RD 430i

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

-II-0.02.02.42.52.75.07.030405060708090100b1C1C4C6d3E2E9EAF7FAFCFdP1P2P3

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