Why is My AC Not Turning On?

Having a home cooling system is a godsend when it comes to enduring the summertime heat. However, it can be quite frustrating when your cooling system fails to turn on when you need it the most. There are a number of reasons that you may be experiencing this issue.

Thermostat Issues

Since cooling systems are complex, you may assume you have a major issue if your air conditioner won’t turn on. However, before calling a professional, you should check your thermostat. Make sure it is in cooling mode. If it is in fan mode, your air conditioner will not kick on, and you will feel warm air coming from your vents. Alternatively, if the screen is blank, the issue could be dead batteries or a tripped circuit breaker. The solution could be as simple as replacing the batteries or resetting the breaker. If the screen is still blank after taking these steps, the issue is probably faulty wiring. In this scenario, you will have to contact a HVAC professional to diagnose and fix the problem.

Dirty Air Filter

If your air conditioner’s air filter needs to be replaced, it may shut down due to overheating. A clogged filter can also cause a host of other issues. Experts suggest changing your cooling system’s filter at least every three months. However, you may need to replace yours more often due to factors like how many people live in your home and if you have pets.

Faulty Starter Capacitor

When the thermostat signals your air conditioner to kick on, its starter capacitor will give your cooling system’s motor a much-needed jolt of energy to start running. If your system fails to start, listen for a distinctive clicking noise. This noise will indicate that your thermostat is functioning correctly, but you have a faulty capacitor. You will need a HVAC technician to replace it.

External Shut-Off Switch

Most outdoor condenser units will have a dedicated sub-panel breaker box. This allows your HVAC technician to shut off your outside unit while they perform maintenance or repairs without having to worry about electrical shock. The outside shut-off switch may simply be in the off position. Pop open the panel and check to ensure the breaker switch is in the on position.

Clogged Drain Line

In many modern AC systems, a safety switch in the drain pan will trigger your entire system to shut off if there’s excess water buildup. This feature is designed to protect your cooling system and prevent water damage to your home. As your cooling system cools your house, it will remove moisture from the air. This moisture forms on the evaporator coils and drips down into the drain pan, which has a drain pipe that runs to the outdoors. If there is a clog in your drain line, the drain pan can back up with water and prevent your system from running. A professional can clear your drain line and reset the system to get it operating again.

Frozen Evaporator Coil

As your air conditioning system runs, hot air from your home is blown over the evaporator coil. The refrigerant inside the coil is pressurized to absorb heat from the air and transport it outside. When dirt and other grime get caked on the surface of the evaporator coil, it can restrict the refrigerant’s ability to pull heat from the air. In turn, the refrigerant will get colder and colder, eventually covering the evaporator coil with ice. The coil must be thawed out and cleaned before your system will function correctly.

A Reset is Needed

If your air conditioner does not restart after a power outage, you may need to reset it. It is possible that when the electricity came back on your cooling system, it experienced a power surge. If you look near the power supply on your outdoor condenser unit, you should find a red reset button. You’ll want to hold this reset button down for around five seconds.

Genuine AC Service

At Cool Experts AC, our team has been serving the residents of Richardson, TX, and the surrounding areas for years. We install, maintain, and repair heating and cooling systems. We also provide indoor air quality services, including duct cleaning and installing whole-home air purification systems. Contact us today to schedule an appointment with one of our experienced HVAC technicians.