re: How far should home A/C be from the setpoint?

quote:

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I never had a problem with the A/C unit, but it seem like when I changed my old thermostat to a new Sensi smart thermostat, I’ve had temp offsets.

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Is there a noticeable change in comfort and do you have a verifiable second way to check temperature?

Typical home AC units may have a tough time reaching 68 at this time of year in the South, ESPECIALLY if the house is older, poorly insulated, etc. It's possible that your AC was never capable of actually reaching 68, but the old thermostat read a little low, so it thought it was 68 when it was really a little warmer in the house and would send the stop signal to the system. If the new one is reading the temperature accurately and the system was never really capable of reaching 68 in the first place, it will run non-stop with the newer thermostat installed and set to 68.

That's why I asked if there was a noticeable difference in comfort. If it's still working like it was before to cool the space, but just is not getting the stop signal, it should feel about the same, but run all the time. Just bumping the thermostat up until it stops running periodically will be all you need to do. After all, the number on the thermostat is completely arbitrary. What's important is whether you're comfortable or not. If the system really is physically degrading, then you'd expect to progressively feel a reduction in comfort as the system gets worse and it'll run all the time.

A second RELIABLE way to check the temperature will verify whether or not the thermostat is correctly measuring the temperature, though it most probably is. Whether you're comfortable or not when you set the thermostat to a temperature that makes the system cycle normally is the real test.