When the heat index climbs, your air conditioner is crucial for your comfort and safety. However, it's not uncommon to forget to turn on the system until the first scorching day, only to find it blows warm air or makes strange noises. The good news is that you can prevent most midsummer breakdowns with a little preparation.

This ultimate summer AC unit checklist has two clear categories, so you know exactly what to do yourself and when to call in a professional. 

DIY Pre-Summer Checklist Essentials

Handle this first phase on a sunny Saturday afternoon — no special tools or technical knowledge needed. These tasks focus on airflow and basic AC hygiene.

1. Clear Debris Around the Outdoor Unit

Your outdoor unit, called the condenser, releases the heat absorbed inside your home. It pulls air through metal fins on the side of the box. If these fins are blocked, the heat is trapped inside. This causes the compressor to overheat, and the system shuts down.

Grab a tape measure and use the 2-foot rule, making sure there is at least 2 feet of clear space on all sides of the unit. You might need to trim back hedges, shrubs, or tall ornamental grasses that have encroached during the spring growing season. North Atlanta is known for pine straw and falling leaves, so clear away any piles of organic matter that have gathered against the unit. This debris restricts airflow and can trap moisture that rusts the equipment.

2. Change or Clean Your Air Filters

The second task on your AC unit checklist is the single most impactful thing you can do. A clogged air filter acts like a wall in your ductwork, blocking airflow. The blower motor works twice as hard to push air through a dirty filter, which bumps up your electricity bill and puts unnecessary strain on the motor.

Changing out a soiled filter for a clean one can lower your AC energy use by 5% to 15%. That is a significant saving for a task that takes two minutes. In summer, check your filter every 30 days. If you have pets or allergies, you might need to change it more often. When the filter appears gray or fuzzy, replace it immediately.

3. Inspect the Condensate Drain Line

Your air conditioner cools the air and removes humidity. Moisture collects in a pan and drains out through a white PVC pipe called the condensate line. In our humid climate, this line stays wet constantly — an ideal environment for algae and mold to thrive. If it clogs with algae, the water backs up. This can trigger a safety switch that shuts off your AC, or a clogged pipe could cause water damage to your ceilings and floors.

Find the access point for your drain line near your indoor unit. It usually has a small cap you can remove. Pour a cup of distilled white vinegar down the line to kill algae and bacteria. Go outside and verify that water is dripping from the exit pipe when the AC is running. If it is dry outside but the AC is running, you likely have a clog that needs attention.

4. Check Vents and Registers

It's a myth that closing vents in unused rooms will save energy. Your HVAC system is designed to push a specific volume of air against a specific amount of pressure. Closing vents increases the pressure in the ductwork. This can cause duct leaks and force the blower motor to work harder.

Walk through every room in your house for this part of the summer AC unit checklist. Make sure all supply vents are open. Check that no furniture, heavy drapes, or area rugs are covering the registers. Your system needs to breathe freely to cool your home efficiently.

5. Test Your Thermostat

Run a test on a mild spring day. If your thermostat uses batteries, replace them now. A weak battery can cause the system to cycle on and off erratically or lose its connection to the main unit.

Turn the setting down at least five degrees lower than the current room temperature. Listen for the click and wait for the system to engage. You should feel cool air coming from the vents within a couple of minutes. If the system does not start, you have time to schedule a repair before the heat becomes dangerous.

When to Call the Pros

The second phase of your AC unit maintenance checklist involves the internal components of your AC system, which deal with high-voltage electricity and high-pressure refrigerant. These areas require specialized tools and safety training. Here are the things a professional checks during a thorough AC unit inspection.

Electrical Connections and Safety Controls

Your AC unit vibrates slightly whenever it runs. This vibration can loosen electrical connections. A loose wire creates resistance, which generates heat. This can lead to burnt wires, melted plastic, and even electrical fires.

A professional technician's checklist for an AC unit includes inspecting and tightening every electrical connection in the system. They will also test the capacitors. These small components act like batteries, providing the jolt your compressor needs to start. If a capacitor is weak, the compressor will struggle to turn on. This generates massive heat and can quickly damage the compressor.

Refrigerant Level Check

Many people think refrigerant is a fuel that gets used up like gas in a car, but this substance actually absorbs the heat from the air. Your AC operates on a closed loop. It should have the same amount of refrigerant in year 10 as it did on day one.

If your refrigerant level is low, you have a leak. Adding more refrigerant without fixing the leak is a waste of money. It is also bad for the environment. Low refrigerant levels drop the pressure in the system, which can cause the indoor coils to freeze over. A professional AC unit preventive maintenance checklist always includes checking these levels and hunting down leaks.

Deep Cleaning the Coils

You cleaned the outside of the unit, but you can't reach the inside. The evaporator coils are located inside your home, usually above the furnace or air handler. These coils are cold and damp, which makes them a magnet for dust and pollen. If they get coated in grime, they can't absorb heat effectively. The system will run constantly but never reach the set temperature. 

Accessing these coils often requires disassembling the metal cabinet. A professional has the tools to open the unit and use chemical cleaners that dissolve the buildup without damaging the aluminum fins.

Lubricating Moving Parts

Motors and fans spin at high speeds and rely on bearings to reduce friction. Over time, the factory lubrication dries out, which results in motors overheating and seizing up. A technician will apply the precise amount of lubricant to these moving parts. This simple step keeps the motors running and extends their lifespan.

Replace or Repair

Sometimes things go wrong despite your best efforts. You may need to decide whether to fix an old unit or buy a new one. Follow the $5,000 rule, multiplying the age of your equipment by the estimated cost of the repair. If the total is less than $5,000, it is usually worth repairing the unit. If the total exceeds $5,000, it is likely time to replace the system.

Energy-Saving Tips for Summer

Keeping your home cool in North Atlanta does not have to result in a massive electric bill. Follow these tips to lower your energy costs:

  • Ceiling fans: While they do not lower a room's temperature, they cool your skin through the wind-chill effect. This may allow you to raise your thermostat setting by a few degrees. Make sure your fans are set to spin counter-clockwise to direct air straight down.
  • Programmable thermostat: This type of thermostat lets you raise the temperature automatically when you leave for work and lower it before you return. Smart thermostats can even adjust themselves.
  • Closed blinds: Solar heat gain through windows accounts for a large portion of your cooling load. Keep blinds and curtains closed on south and west-facing windows to block heat from entering your home.

Stay Cool With One Hour Heating & Air Conditioning®

By handling the basic tasks yourself and trusting the technical work to the experts, you can enjoy a cool and worry-free summer. If you want to put your maintenance on autopilot, sign up for our Club Membership so you never miss a tuneup and keep your warranty valid.

Let our pros handle the technical side of your summer AC unit checklist so you can relax. Contact us today to schedule your comprehensive summer tuneup. We are here to help North Atlanta stay cool all summer long.