Turning down the thermostat only to have your air conditioner refuse to kick on is clearly a problem. But what if you have the opposite happen to you? What if your air conditioner kicks on without complaint, but then it won't turn off? Thankfully, there are steps you can take to get to the root of the problem and hopefully solve it. Here's a look.
Step One: Make Sure Your Thermostat Is Set to "Auto"
You might assume that the appropriate setting for your thermostat is "on." But in fact, this setting usually specifies that the fan will stay on constantly, though the air conditioner may turn on and off throughout the day. If your thermostat is set to "on," this might actually be what's happening -- air is coming out constantly, but if you feel it, you'll notice that it is only cool for a few minutes at a time. Turn the thermostat to "auto," and this should fix the problem. If it doesn't, or if your thermostat was already set to "auto," then you need to move on to step two.
Step Two: Change the Air Filter
If the air filter in your air conditioner is dirty, the air conditioner will have to work especially hard to force air through the filter. This might cause the air conditioner to overheat. The heat it gives off might counteract the coolness it releases. The air conditioner then has to run, and run, and run to get your home cool. Try pulling out the old filter and putting a new one in its place. Then, remember to keep replacing the filter every month or two to prevent this issue from popping up again.
Step Three: Check the Fan Limit Switch
Some air conditioners have a switch called the fan limit switch. If this switch is "turned on," the air conditioner's fan will keep running constantly, regardless of the setting on the thermostat. This switch might be located on the back of the AC unit, or on one side near the ground. Turn it off if it is on -- this should solve your problem.
Step Four: Call Your HVAC Contractor
If the thermostat, limit switch, and fan filter are not to blame, then you need to call your HVAC company. There might be an issue with the electrical wiring of the unit, or the motor may be experiencing some trouble. Your air conditioning repair contractor can check the system over and get to the bottom of the issue.