A.O. Smith Error Code 721: The A.O. Smith Hot Water System’s Error Code 721 means that there is a problem with the flame in your water heater. It is detecting a false flame, which means it is not working correctly. To fix this issue, you should check if there is any condensation inside the heater. This can happen if the condensate drain is not properly installed on the vent collar of the water heater. If this is the case, there might be water in the internal combustion engine, which needs to be addressed
A.O. Smith Hot Water – Error Code 721
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A.O. Smith Hot Water System – Error Code 721
Is your A.O. Smith hot water system showing up with Error Code 721 on the screen? In this article, we’ll look at why it is happening, some potential next steps for fixing error code 721 and whether you should keep using your A.O. Smith hot water system.
What is a A.O. Smith Error Code 721?
The A.O. Smith Hot Water System’s Error Code 721 means that there is a problem with the flame in your water heater. It is detecting a false flame, which means it is not working correctly. To fix this issue, you should check if there is any condensation inside the heater. This can happen if the condensate drain is not properly installed on the vent collar of the water heater. If this is the case, there might be water in the internal combustion engine, which needs to be addressed
Recommended solution/fix steps
The first step to take when you see Error Code 721 on your A.O. Smith Hot Water System is to check for any condensation within the heater. If you find any, you need to ensure that the condensate drain is properly installed on the vent collar of the water heater. If the drain is not installed correctly, water can accumulate in the internal combustion engine, causing a false flame to be detected. Once you have checked and fixed the condensate drain, reset the water heater by turning off the power supply and then turning it back on after a few minutes. If the error code persists, it is recommended to contact a professional technician to diagnose and fix the issue
Fault codes that are often associated with or mistaken for error code 721 are: 722, 7Z1, 7210, 7211, 7215, 7218, 721b, 72i, 7a1, 7b1
Can I still use my A.O. Smith hot water system?
After seeing Error Code 721 on the A.O. Smith Hot Water System, the machine should not be operated until the issue is resolved. This error indicates the presence of a false flame within the water heater, which can be a safety concern. To fix this problem, it is necessary to check for condensation within the heater. If the condensate drain is not correctly installed on the vent collar, water may accumulate in the internal combustion engine. Operating the machine in such a condition can lead to further damage and potential hazards. Therefore, it is crucial to address the issue promptly and ensure proper installation of the condensate drain before operating the water heater again
