Learn how to find and solve issues with your home air conditioner.
Your home air conditioner keeps your house cool when it’s hot outside. If it’s not working right, you might want to call a repair company. Before spending money on a repair company, try fixing the air conditioner issue yourself. It could save you money. Follow this guide to learn about common problems and how to fix them at home.
Common issues with home air conditioners
Condenser Doesn’t Start
The condenser is the part of the air conditioner that’s outside. If it doesn’t start, your AC won’t work. This could happen because the thermostat is set too high. If the thermostat is okay, it might be a problem with the compressor, motor, or power supply. If you think it’s a big problem, call a professional for help.
Uneven Cooling
Sometimes, your air conditioner may be fine, but you’ll notice that some parts of your home are cooler than others. This happens when vents are closed or blocked. Make sure all vents are open and clean to balance the cool air throughout your home.
Inadequate Cooling
If your air conditioner appears to be running fine but your home’s temperature doesn’t decrease, there are a few potential reasons. First, ensure the thermostat is set correctly; if it’s too high, the AC might shut off before cooling the house properly.
Another possibility is dirty evaporator coils, which can usually be fixed by cleaning them. However, inadequate cooling could also indicate that your AC unit is too small for your home. In such cases, it’s best to seek advice from an air conditioning professional to determine if an upgrade is needed.
No Cooling
If your air conditioner turns on but blows air at the same temperature as the rest of your home, it’s not cooling properly. First, check if the thermostat is set correctly. If it’s fine, the issue might be dirty condenser coils, evaporator coils, a blocked condensate drain line, low refrigerant levels, or a faulty compressor.
Experienced DIYers can usually clean coils and clear blocked drain lines. However, for compressor replacement or refrigerant recharge, it’s best to call a professional air conditioner repair service.
Condenser Turning On and Off Repeatedly
Your air conditioner may try to start when the inside temperature reaches the thermostat setting, but if the condenser is blocked by trees, plants, or other objects, it might turn on and off repeatedly. This could also happen due to faulty wiring or dirty condenser and evaporator coils.
Trimming foliage around the unit might fix the problem, or you may need to clean the coils. If you suspect damaged wiring causing intermittent power issues, it’s best to call an air conditioner repair professional for repairs or replacements.
Thermostat Troubles
When your thermostat malfunctions, it affects the entire HVAC system. Think of it as the system’s brain. Thermostats need power to function, which can come from batteries, low voltage wires, or both. If the power is disrupted, the thermostat won’t work properly. Also, if the thermostat is poorly positioned in your home, like in direct sunlight or near a drafty area, it can cause issues.
Items Needed
Equipment / Tools
- Flashlight
- Screwdriver
- Shop vacuum
- Shovel
- Pruning shears
- Hand mirror
- Stiff-bristle brush
Materials
- Replacement fuse
- Thermostat battery
- Replacement air filter
- Microfiber cloth
- Duct tape
- Coolant line insulation
Repairing Your Home Air Conditioner
Check the Breaker or Fuse Panel
Sometimes, a power surge or short circuit can trip the breaker or blow a fuse, causing the air conditioner to lose power. If your AC isn’t working, check the breaker or fuse panel. Resetting a tripped breaker or replacing a blown fuse should fix the problem. However, if the issue repeats, you might have a more serious electrical problem that requires assistance from an air conditioner repair professional or an electrician.
Changing the Filter
When your air conditioner blows warm or hot air instead of cold air at the right temperature, it could be due to a dirty air filter. Replacing the filter is easy and should be part of regular maintenance. Simply remove the old, clogged filter and replace it with a new one, ensuring it’s installed in the correct direction as indicated by the arrows.
Testing the Thermostat
Another common issue is the thermostat. It controls when the air conditioner turns on based on the temperature you set. If the thermostat’s batteries are dead or the low voltage wire connection is loose, it can’t signal the AC to start. Replace the battery or check the wire connection to restore power.
If the thermostat has power, the problem might be the temperature setting being too high. Lowering it should activate the AC. Sometimes, the thermostat is poorly placed in direct sunlight or drafty areas, affecting its temperature reading. You can try moving a battery-powered thermostat yourself or hire a professional to relocate a hardwired one for better accuracy.
Removing Ice Build-Up
Sometimes, your air conditioner might run for a long time, causing ice to form on it. To fix this, you can either switch off the cooling function so only the fan operates, or turn off the entire HVAC system. Letting the ice melt naturally will free up the air conditioner.
Cleaning the Vents
To ensure even cooling, it’s important that cooled air can flow freely through the ventilation system. Check all the vents in your home to make sure they’re open, clean, and not blocked by anything like furniture or rugs.
Clearing Space Around the Compressor
Your HVAC system’s compressor can be located in various places around your home, such as the front, side, or back. Typically, there’s enough space around the compressor for proper airflow. However, if it’s surrounded by gardens, trees, or bushes, overgrowth during warmer months can block airflow and hinder the air conditioner’s function.
Trimming bushes, trees, and other foliage around the compressor is essential to prevent overheating and obstruction. Ensure there’s about two to three feet of space around the unit and five feet of clearance above it.
Inspecting the Air Ducts
To ensure even and efficient cooling, it’s crucial to have open, clean, and unobstructed vents. However, even with clean vents, airflow can still be restricted if the ducts are dirty. Check the air ducts for significant dust, dirt, hair, or debris buildup. While you can vacuum short sections of ducts yourself, it’s best to hire an HVAC maintenance professional for longer runs and complete home duct cleaning.
Cleaning the Evaporator Coils
Dirty evaporator coils can reduce the cooling output of your air conditioner, leading to inadequate cooling or frequent on/off cycles. Check if the evaporator coils are accessible in your HVAC system. If so, they’re typically behind foil-wrapped insulation at the front of the plenum box.
First, turn off the air conditioner and remove the tape and screws holding the access plate in place. Use a stiff-bristle brush and mild detergent to clean the entire evaporator unit. A small hand mirror can help you see better during the cleaning process. Don’t forget to clean the collection tray below the unit and use a wet/dry shop vac to clear the drain line. Finally, reinstall the access plate and tape the insulation back into position.
Cleaning the Compressor Coils
Inspect the compressor coils outside for dirt, dust, and debris buildup. Use a mild detergent with a soft-bristle brush or microfiber cloth to gently clean the coils. After cleaning, disconnect the condensate drain line and use a shop vac to remove any obstructions.
Examining the Coolant Lines
Most air conditioning systems use Freon as a refrigerant coolant. Inspect the coolant lines for damage, as leaks can lead to low coolant levels, affecting the AC’s cooling ability.
Replace any damaged or worn insulation on the coolant lines and check for leaks. If you find leaks or low coolant levels, it’s best to contact a professional air conditioner repair service. Avoid attempting to patch leaks or recharge the coolant lines yourself.