What To Do When Your A/C Loses Control

As a Florida native myself, I’m not sure how it happens but the A/C just gets tired of cooling down my house and it starts pushing out warm air. When this happens, I always turn off my A/C, give it about thirty minutes to an hour break, and then I turn it back on. This usually fixes the issue.

Yet, sometimes the issue can be as strange as replacing your A/C with new controls and the A/C will only run if both the temperature and the humidity settings are exceeded. What should you do then? Good question. The air conditioner only turns on if it meets the set points on either the thermostat or the humidistat.

Some steps to take to reconfigure these settings on your new controls for your air conditioner:

  • Check to see if the temperature alone turns on the air conditioner.

Set the humidistat to the highest relative humidity requirement. Then, set the thermostat to the lowest temperature setting. If the air conditioner turns on after a few minutes, the thermostat can control the air conditioner by itself.


  • Check to see if relative humidity alone turns on the air conditioner.

Set the thermostat cooling setting to the highest temperature, and then set the humidistat to the lowest relative humidity requirement. If the air conditioner turns on after a few minutes, it confirms that the humidistat can control it by itself.


If the air conditioner turns on with both of these steps then Romark A/C recommends setting the humidistat at 58 percent relative humidity and your thermostat temperature setting to 88 degrees.

However, if the air conditioner fails to turn on either of these two steps, this recommendation is not appropriate and we recommend referring to your manufacturer recommendations. There are various reasons for why this may occur and further research may be required to determine a common control strategy.

Be careful not to leave your thermostat fan in the “on” position. The reasons for this is because it causes the relative humidity in your house to rise due to moisture building up on the inside coil of your air conditioning unit. Furthermore, if you’re in a humid climate, you may push the air in your home into the mold-growing range of relative humidity, especially if your air conditioner is oversized. Moreover, your energy bills will be higher. You’ll increase your total duct leakage because the fan will be running all the time. If you have unbalanced duct leakage, you may also increase the air leakage across your building enclosure. Just be aware that the change in the humidity in your house may take a couple days to decrease below sixty percent when you turn your thermostat fan from “on” to the “auto” position.

You can prevent weird issues like these and many more by scheduling an appointment for a free energy review today. Book it before the pre-summer season quickly approaches and the humidity gets too sticky and the heat to hot to handle.


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