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Heating  Heating

Brand

AO Smith AO Smith List all brands

Type:

ATI-510C-N view ATI-510C-N List all types

Error code:

721
List all errors


Error code: 721

Cause of error code 721

False flame detection

Solution for error code 721

• Check if condensate drain is installed on the vent collar of the water heater. • Check if there is leaking from heat exchanger (Part #401).


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