As the world outside begins to thaw, and the warmer months of spring and summer arrive, it won’t be long before it is time to turn on the air conditioner. However, if your central air conditioner won’t turn on or doesn’t blow cool air, then you will need to take a closer look to see what’s happening.
The steps below are quick and easy to perform and require little specialized knowledge from homeowners. Below is more information on what to do if your air conditioner isn’t working properly when you are ready to use it.
- Make Sure the Thermostat Is Set to Cool
The first place to check for trouble is the thermostat itself. If your thermostat serves both your furnace and central air conditioning system, then it should provide options to either cool or heat your home. Most thermostats also have a fan option that simply blows unheated and uncooled air. An improper setting will prevent your system from producing cold air.
This is a common source of trouble but an easy problem to fix. If air is blowing from the vents but isn’t cold, then check to see if the thermostat is actually set to “cool” and not on fan mode. Likewise, if nothing at all is happening, be sure the thermostat is set on “cool” and not “heat,” as it is easy to forget to make the change after a long winter.
- Turn the Thermostat to a Lower Setting
If the thermostat seems to be on its proper setting of “cool,” but you’re still not experiencing any activity, the temperature setting may not be adjusted to a sufficiently cool level. This can be common with dial-type thermostats, as the numbers on the dial may not always align with actual temperatures inside the house.
Be sure to turn the dial well-below the current temperature indicator on the thermostat; this will give the thermostat a chance to engage and activate cooling. If that solves the problem, it may be an indicator that you need a newer, more accurate thermostat and should consult an air conditioning professional for help.
- Change the Thermostat Batteries
If you have a digital thermostat with an electronic readout, then it is possible the batteries may be nearly or completely discharged. Many digital units use manual switches, but a dead battery will prevent the thermostat from sending a cooling command to the unit, regardless of the switch setting. Before replacing the battery, consult the owner’s manual for your particular model to learn how to perform the replacement.
- Check for Power at the Main Breaker Box
A tripped breaker can also keep your air conditioner from working. You won’t be able to tell if the breaker was tripped by looking at the thermostat, so if you are confident the thermostat has fresh batteries and is properly set, then take a look at the breaker itself.
Your air conditioning system should have its own circuit, and if the panel is properly marked, you will be able to tell if the breaker switched itself off. Flip the breaker switch back on, and then attempt to restart the air conditioner at the thermostat. If the breaker trips again, then you will need to contact an air conditioning specialist to determine the cause of the problem.
- Verify That the Power Switch on the Outdoor Unit Is On
The outdoor unit of your central air conditioning system houses the compressor and condenser coils. The compressor has its own power switch located nearby on the house, and this switch may have been turned off for the winter. However, if it is turned off, it will prevent the compressor from cooling your air and will need to be turned back on again to restore full functionality.
- Listen for a Proper Compressor Startup
If you are still experiencing a lack of cool air and have verified that the thermostat, main system, and outdoor unit are all powered on, then another common problem is a failure of the compressor startup capacitor.
This electronic component is sealed inside the outdoor unit and provides an initial “jolt” of electric current to get the compressor motor started. When this component fails, you will hear a faint, but distinct, humming noise from the outdoor unit. In addition, the indoor fan may still blow but won’t produce cool air. If you believe the capacitor is bad, you will need to contact an air conditioning specialist for diagnosis and replacement of the capacitor.