Low
Application of power on Ideal RD2

Your boiler is simply indicating that electrical power has just been applied to it, which is a normal startup status rather than an actual fault.

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

Flash > 1/sec in sync with LED 4

Shared across the British / Scottish 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

Wait a moment to see if the boiler transitions to normal operation automatically.If the boiler remains stuck on this startup indicator, try turning the main power switch off and on again to reset it.

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All 10 fault codes on the RD2

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

Control 'stat open circuit or waiting for demandFan start upLED 3LED 4Lock-outPump over-runReverse polarityRunSensor Faults

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