AC Electrical Problems Every Homeowner Should Know

As summer heatwaves intensify across the U.S., particularly in the Pacific Northwest, homeowners are relying more than ever on their air conditioning to stay cool. In 2024, Oregon recorded its sixth-warmest year on record, with some cities sweltering through five consecutive days over 100°F. But with the rise in AC use comes an increase in electrical problems—issues that can quickly escalate if not addressed. Here’s what you need to know to keep your AC running smoothly during the hottest months.

Discover six common AC electrical problems to watch for this summer and know when it’s time to call in a professional. Learn how to identify these issues and avoid discomfort during the heat.

1) Frequent Circuit Breaker Trips

It’s a red flag if your circuit breaker frequently trips when your AC kicks on at home. This is a sign that something is wrong with your AC system. Problems can include a failing compressor, loose wiring, or short circuits. Resetting your electrical system is not a solution—call an electrical professional to fix the root issue before it progresses into a bigger problem.

2) Faulty Capacitors

Capacitors are small but powerful parts of your AC system. They provide the jolt of energy needed to start the compressor and keep the fan motors running. When you have a failing capacitor, you may notice your AC struggling to start, making humming noises, or shutting off unexpectedly. Sometimes the unit may not turn on at all with faulty capacitors. You should leave the diagnosis and replacement of capacitors to an electrician because handling them can be hazardous.

3) Burnt or Frayed Wiring

Over time, the wiring in your AC system can wear out from heat, vibrations, moisture, or even pests. When wires become burnt or frayed, they pose serious fire risks and can cause your AC to malfunction. Damaged wires disrupt electrical flow, often causing the system to stop working entirely. Be on the lookout for signs like burning smells, blackened insulation, or intermittent power loss—these could mean there’s an issue with your wiring. If you notice any of these, turn off your AC and call a licensed technician to fix or replace the wiring.

4) Compressor Not Getting Power

When your AC is still running but not pushing out cool air, the compressor may not be getting the power it needs. The culprit can be a number of different things, including a failed contactor, blown fuse, or damaged wiring. When the compressor is without power, the AC cannot circulate refrigerant to cool your house. An electrical professional can diagnose the root cause through electrical testing.

5) Thermostat Wiring Issues

If your AC is responding inconsistently, it could be an issue with the thermostat wiring. There may be loose, corroded, or disconnected wires impacting communication between your thermostat and HVAC system. This prevents the AC from receiving the right signals to perform properly. When you have thermostat wiring issues, you might notice the display flickering or temperature settings being ignored. An electrical professional can work with the low-voltage circuits connected to your HVAC controls to handle rewiring.

6) Malfunctioning Contactor

A contactor is a vital electrical switch controlling the flow of electricity to the AC compressor and condenser fan motor. Malfunctions due to wear, dirt, or electrical arcing are common. These malfunctions may cause your AC not to start, to run continuously, or make a clicking sound when trying to turn on. If ignored, a malfunctioning contactor can cause strain to other parts of the AC system and lead to bigger issues.

Contact a Local Electrician for Air Conditioning Repairs, Install & More

Stay comfortable in warm temperatures this summer by spotting AC electrical problems early and calling a skilled electrical pro. Our electricians are fully licensed and bonded, and provide expert services for homeowners in the Pacific Northwest. Find a contractor near you today.