HVAC Outside Unit Not Running: What to Do

October 08, 2019

When your HVAC outside unit is not running, it can be a major inconvenience, disrupting your home’s comfort and efficiency. While there are many potential causes, one common issue many homeowners overlook is debris, such as leaves in the AC unit, especially during the fall.

While the season brings beautiful foliage, it also means more yard work, and those leaves can easily clog your HVAC system without you realizing it. If left unaddressed, these blockages can damage the system and even pose safety risks. Read on to learn about common causes and solutions for outdoor unit issues.

Why Is My Outside HVAC Unit Not Turning On?

If your HVAC outside unit is not running, several potential reasons exist. Some issues can be simple to resolve, while others require the expertise of a professional technician. Here’s a look at some of the most common causes.

Power Issues and Tripped Breakers

The power supply is one of the first to check if your HVAC outside unit is not running. Ensure the unit is plugged in and that the breaker hasn’t tripped. Power surges or electrical issues can cause a loss of power to your outdoor unit.

Clogs and Debris

Debris, like leaves in the air conditioner unit, can clog the system. These blockages can obstruct airflow, causing the unit to shut down. Keeping both your furnace pipes and your AC unit cleared of leaves is very important for system efficiency, home comfort, and safety. Keeping your HVAC system clear of debris can also help keep your HVAC ducts clear.

Clogged Air Filter

A dirty or clogged air filter can restrict airflow, leading to an overheating system that might shut down as a safety precaution. Replacing the filter regularly can help prevent this issue.

Capacitor Problems

The capacitor supplies power to the compressor and fan motor. If the capacitor fails, your outdoor unit won’t start. You may hear a clicking noise as the unit attempts to start without success.

Compressor Contactor Issues

The compressor contactor acts as a switch, allowing power to flow to the compressor and fan. If it’s malfunctioning, the HVAC outside unit’s not running is a likely outcome, as the system can’t receive the power needed to start.

Burnt-Out Air Conditioner Fan Motor

A faulty fan motor can prevent the outdoor unit from turning on. The fan motor helps expel hot air from the unit, but if it’s burnt out, the system may overheat and shut down.

Dirty or Clogged Condenser Coils

The condenser coils are crucial for releasing heat from your system. If they’re covered with dirt, dust, or leaves, it can prevent proper heat exchange, causing your HVAC outside unit to malfunction.

Refrigerant Leaks

Low refrigerant levels due to leaks can prevent the unit from functioning properly. If you notice that your HVAC system is blowing warm air, it could be a sign of a refrigerant issue.

These are some of the most common reasons for an outside HVAC unit to stop running. While you can take a few steps on your own, many issues require a professional to diagnose and repair. For expert service, call A.J. Perri at 732-733-2541 or schedule a service online.

How to Safely Clear Leaves from Your AC Unit

Keeping your HVAC unit free of debris is crucial, but DIY maintenance does come with risks. Here are a few quick and safe steps you can follow:

Turn Off the Power: Before cleaning, switch off the power to your outdoor unit to prevent electrical hazards.
Remove Debris Carefully: Gently use a vacuum or a soft brush to clear away visible leaves around the air conditioner without damaging the fins.
Inspect Intake and Exhaust Pipes: Check the pipes for any blockages. If leaves block your intake pipe, the furnace will stop working because air can’t enter, but a blocked exhaust pipe can be dangerous.

While these steps can help, contacting a professional for a comprehensive inspection is best. DIY efforts might void your warranty or miss underlying problems. Call A.J. Perri at 732-733-2541 today for expert assistance.

Why Is My Outside Unit Not Running but the Inside Is?

If the inside HVAC system seems to be running, but your outside unit is not running, it’s usually a sign that something is preventing the outdoor unit from activating properly. Here are the most common causes and what you can do.

Thermostat Issues

A faulty thermostat can be a simple but often overlooked reason for the HVAC outside unit not running. Check that the thermostat is set to "cool" and that the temperature is set lower than your current indoor temperature. If it’s a smart thermostat, ensure it’s properly connected to Wi-Fi and receiving updates.

Tripped Breaker or Blown Fuse

The outside unit has its own power supply, usually connected to your home’s electrical panel. A tripped breaker or blown fuse can easily disrupt the power flow, causing the HVAC outside unit to stop running even though the inside system appears to be working fine. Reset the breaker if needed, but if it continues to trip, there may be a deeper electrical issue.

Capacitor or Contactor Problems

The capacitor and contactor are crucial components of the outdoor unit. The capacitor supplies the initial jolt of power needed to start the compressor and fan motor, while the contactor acts as a switch for the power. If either fails, your HVAC outside unit is not running, even though the indoor system seems operational. These components typically require professional replacement.

What to Do if Your Outside HVAC Unit Isn’t Running

If your HVAC outside unit is not running, you can try these simple troubleshooting steps before contacting a professional:

Check the Thermostat: Confirm it’s set to "cool" with a temperature lower than the room’s current setting.
Inspect the Circuit Breaker: Look for a tripped breaker and reset it if necessary. Repeated trips may indicate an electrical issue needing a technician’s attention.
Clear Debris: Switch off the unit’s power and gently remove any visible leaves or dirt. Debris like leaves in the AC unit can block airflow and impact performance.
Try the Reset Button: After turning off power, press the unit’s reset button, then switch the power back on to see if it resolves the issue.

If the problem persists, DIY repairs could risk further damage or void your warranty. It’s best to contact A.J. Perri at 732-733-2541 for expert help.

When to Call a Professional

While basic troubleshooting can sometimes resolve minor issues, there are clear signs that it’s time to call in an expert. If you’re unsure what the problem is or your HVAC outside unit is not running due to repeated power issues, visible damage, unusual noises, or refrigerant leaks, it’s best not to risk DIY fixes. Problems like a faulty capacitor, compressor contactor issues, or a burnt-out fan motor require specialized knowledge and equipment.

A.J. Perri’s team of skilled technicians is here to help New Jersey homeowners keep their HVAC systems running smoothly, no matter the season. We provide thorough inspections, repairs, and maintenance services to ensure your system is ready for whatever weather comes your way. Contact us today at 732-733-2541 or schedule service online for expert assistance you can trust.