It's not unusual for a system that has been shut down for the winter to not turn back on when warm weather arrives. If your central air conditioning system won't turn on this summer, don't panic; instead, take a closer look at a few common causes, and you are likely to discover it isn't as bad as it seems. Below are a few easy-to-check potential trouble spots.

Depleted Thermostat Batteries

One of the most common problems that can prevent a central air conditioning system from turning on is depleted batteries in the thermostat. Many types of thermostats, particularly those with programmable or LCD displays, utilize batteries to power their functions.

If your thermostat isn't responding to your input or the display appears to be dark, then you will need to replace the batteries, which is a simple task that any homeowner can do. Simply grasp the thermostat front cover and firmly pull it forward to release it from the back panel.

This action will expose the batteries, which can then be easily replaced with new ones. Snap the panel back on and verify the display is visible once again.

Circuit Breaker Tripped

Another common problem that can prevent your air conditioner from powering on is a tripped circuit breaker. Locate the circuit breaker panel in your home and search for the appropriate breaker switch. Most panels have a list printed on the inside of the panel door that will direct you to the appropriate switch; use this guide if you have trouble finding the affected switch.

Once you locate the switch, turn it fully off, then on again to ensure it resets. Next, check the air conditioning system for restored functionality to verify the problem was solved.

As a word of caution, should the circuit breaker continue to trip and you find yourself repeatedly needing to restore the power via the switch, this could be an indicator of an internal wiring problem. Such an event will require a service call to verify there are no dangerous situations present. Don't take a chance on a possible electrical fire by ignoring a potentially deadly problem.

Outdoor Unit Power Switch Turned Off

Many central air conditioning systems have a separate power supply switch located in close proximity to the outdoor condenser/compressor unit. This power switch may have been turned off during the fall or winter, and it must be activated to make your system functional.

Look for the outdoor unit power switch on the exterior wall of your home in a location near the outdoor unit. It may be a simple lever-style switch that needs to be flipped to restore power. In some cases, the outdoor unit power switch is a handle that is pulled from its socket and needs reinsertion to restore power.

If you aren't able to locate a missing handle switch, then you will need to contact a service professional for assistance in replacing the part. Never attempt to insert any other objects into the power socket, as this circuit contains 240 volts of alternating current (AC) and could kill or cause a serious injury.

Blown Start/Run Capacitor

Another problem that can prevent your central air conditioning system from operating is a blown start/run capacitor. This small but vital component provides a surge of electricity that starts the compressor. It isn't rare for this capacitor to fail, especially as it ages.

To check for a blown start/run capacitor, attempt to turn on air conditioner at the thermostat, then stand next to the outside unit and listen for a humming or buzzing noise. The presence of this noise is a tell-tale indicator of a blown capacitor.

If you believe the start/run capacitor has failed, contact an air conditioning service professional for assistance. They can quickly and easily make the replacement in most cases and restore the flow of refreshing, cool air inside your home.

If you live in southern Missouri in the Branson or Springfield area, be sure to contact Knight Heating and Air Conditioning for assistance. They can provide you with reliable, affordable service and get your system back into operation.