BoilerFaultCodes.com
20 Low Warning

Your boiler has identified a temporary electronic error and is likely trying to restart itself automatically.

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.

Technical description: Temporary fault code (Refer to section 7.10)

What causes this fault?

This fault occurs when the boiler's control system encounters a momentary communication error or an unstable electrical signal. It is usually caused by the internal computer board failing to receive a clear confirmation that the burner has lit correctly, or a brief glitch in the electronic sequences. The boiler will typically attempt to clear this itself before deciding whether to stop completely.

Typical repair cost £80-160 (including labour)

DIY fix possible

Check if the boiler clears the code and restarts automatically after a few minutesTurn the mode selector switch to the 'OFF/RESET' position, wait five seconds, then turn it back to 'ON'Ensure your gas supply is active (e.g. check other gas appliances)

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