7 Most Common Reasons Your Air Conditioning System Isn’t Working

cleaning an air conditioner

While many love the dog days of summer, most of us look forward to the cool comfort of our air conditioning when we return home after a long day. Unfortunately, air conditioner problems usually happen on the hottest days of the year, right when you need your air conditioner most.

Fortunately, some issues can be solved without a call to your local HVAC service contractor.

Here are seven of the most common air conditioner problems, along with some helpful advice to solve many simple issues on your own.

Why is my AC running, but not cooling my house?

Dirty Air Filter

A dirty air filter can block the normal airflow that your air conditioner requires in order to run efficiently. Blocked airflow often leads to coil freezing, which can prevent your air conditioner from cooling your home effectively. Check your air conditioner filter and clean, or replace it if it’s dirty.

Refrigerant Leak

Your air conditioner’s refrigerant is responsible for removing heat and humidity from the air. When there’s a leak, refrigerant levels drop, adversely affecting the efficiency of your air conditioner. If the leak is severe enough, the air conditioner might not have enough refrigerant available to cool the air in your home or office. Unfortunately adding more refrigerant won’t fix the problem, especially when there are multiple leaks. The best course of action is to contact a qualified HVAC repair technician who can check the system for leaks and repair any holes in the refrigerant lines.

Condensate Drainage Issues

Your air conditioning system removes water from the air and routes that water into a pan which then goes down a drain. Modern air conditioners are designed to shut down when the water in the condensate pan overflows. If the drain becomes clogged, the water in the pan will continue to accumulate until it overflows, causing the air conditioner to shut down.

Having regular maintenance performed on your air conditioning system can help prevent drainage clogs. If you think you have a clogged drain, contact a qualified HVAC technician or plumber to assess the situation.

Seized Compressor

The compressor is responsible for moving the refrigerant through the AC coils to perform heat exchange. If the compressor stops working, the AC unit will not cool your home.

The most common reason for compressor failure is overheating. When the system does not have sufficient refrigerant, the compressor can run hot and eventually seize. If your compressor has failed, an HVAC technician can assess the problem and determine if you need to replace the compressor or invest in a new air conditioning system.

Why did my AC stop working?

AC System Power Issues

Check the power switch on your furnace or outdoor compressor to make sure the system is on. You’ll also want to check the compressor disconnect, usually contained in a metal box mounted near the compressor.

If the power switch and compressor disconnect check out, you’ll want to check for a tripped breaker or blown fuse.

Check the main circuit box in your home for a tripped breaker and reset it to see if that fixes the problem. If the system turns on, but trips the breaker again shortly thereafter, you could have a short in your wiring. Turn off the system and call an HVAC technician to troubleshoot the issue further.

Thermostat Issues

An incorrectly calibrated thermostat may not be sending the right information to your cooling system, preventing your air conditioner from activating when the temperature rises above comfortable levels. This is especially true if you are using an older, dial-type thermostat.

Newer, programmable thermostats can also cause problems if they are not set properly. Be sure to check the manual for your thermostat to be sure it is set correctly.

To see if the thermostat could be causing your cooling issues, check to see if it is set to COOL and that the temperature is set at least 3 degrees below the current room temperature.

If you have a programmable thermostat that isn’t displaying information, its batteries might need to be replaced. Simply pull off the panel cover to access the batteries and replace them. Replace the cover and wait about 5 minutes. Then try the system again.

If you still experience problems, it may be time to replace the thermostat altogether. A qualified HVAC technician can help you determine if the thermostat is the cause of your air conditioning issues.

Bad Capacitors

Air conditioners use two capacitors, a start capacitor to activate the AC motor and a run capacitor to keep the motor running after it starts. If either capacitor burns out, the air conditioner may not run efficiently. If both capacitors burn out, the AC unit may not run at all. If you suspect a problem with your AC system’s capacitors, contact a qualified HVAC technician.

Ways to Keep Your AC Running

Install a Programmable Thermostat

One of the best ways to keep your air conditioning system in tip-top shape is to install a programmable thermostat. New, programmable thermostats are more accurate than older models, so your air conditioner won’t need to work as hard to maintain the correct temperature. Programmable thermostats can also help you save on your energy bills by cooling your home on a preset schedule, reducing the load on your air conditioner when you aren’t home.

Regularly Clean or Replace Filters

One of the most common reasons for inefficient air conditioning is a dirty air filter. As mentioned above, your air conditioner needs air to run properly. When dust and debris gather in the filter, this airflow is blocked, causing your air conditioner to work much harder than it needs to.

But cleaning or replacing the air conditioner filter at the intervals recommended by your system’s manufacturer can help you avoid airflow problems and keep your air conditioner running more efficiently. It’s also helpful to keep an extra filter on hand in case you run into problems.

Schedule Regular Maintenance

No matter which HVAC system you use to cool your home, it’s important to perform regular maintenance to keep your system running efficiently. HVAC systems have a lot of moving parts that should be inspected, adjusted, or lubricated periodically to prevent breakdowns. We recommend servicing your air conditioning system at least once a year, preferably in the spring, before hot weather begins, or in the fall after your system is done for the season.

While no one wants to come home to a hot house during the dog days of summer, many of the most common reasons for air conditioner problems are easy to fix. You can prevent even more problems by scheduling regular system maintenance to catch problems early before they lead to bigger, more expensive issues in the future.

Need Professional Air Conditioning Service or Have Questions About Your System?

Garden Spot Mechanical is your trusted heating and cooling expert in the Lancaster County, PA area. We offer a full range of HVAC services designed to keep your system running at peak efficiency, even on the hottest days of the year. Get in touch with us for HVAC service or to discuss our custom maintenance plans.