Window AC units are the quickest and most affordable ways to cool bedrooms, dorm rooms, and small apartments. However, they can fail – just like any other type of air conditioner.
The most common reasons window air conditioners breakdown is due to clogged/dirty air filters, a broken fan or motor, and a blocked condensate drain line. You can troubleshoot and fix some of these issues by removing the access panels to clean them. But in some cases, you will need to have an HVAC technician service it, or you may need a new one entirely if it has a refrigerant leak.
All types of air conditioners come with their pros and cons. Here’s some insight into how window AC units function and how you can tackle four common issues that most window air conditioner owners face.
4 Common Issues and DIYs for Window Air Conditioners
The average life span of window air conditioners is ten years. However, they could give you some trouble over this period. See common AC problems in the dropdown tabs below:
The most common issue with window air conditioners is when they stop blowing cool air. When this happens, you might think you need to replace your AC unit. However, more often than not, dirty air filters are to blame.
Remember to check for a clogged air filter the next time your window AC malfunctions. When the filter is dirty, ice or frost can also accumulate, further restricting airflow.
You can remove the air filter, vacuum off the dust, wash it under the sink, dry it, and then put it back in the window AC unit. First, turn off and unplug the AC unit to clean the air filter. Then, open the front panel and remove the filter, usually located behind the control panel or thermostat. You can lightly tap the filter over a trash can to knock off the dust and give it a once over with a vacuum with a soft brush attachment. Then, rinse the filter under warm running water to clear any stuck-on debris. Let the filter dry completely before reinstalling — you can use a hair dryer on the low setting to speed things up.
Cleaning air filters regularly can help prevent dirt accumulations leading to restricted airflow. Dirty filters make the unit work harder to push cold air through, leading to higher energy bills. Plus, a clean air filter will lead to better indoor air quality in your room.
Another reason your window AC may not be cooling enough is a broken fan or fan motor. The fan motor is a mechanical component that needs to be oiled routinely to prevent overheating and guarantee smooth operation. Alternatively, your fan belt may have snapped from normal wear and tear.
Signs of a broken fan or motor include strange noises when the unit turns on, the fan wobbling instead of spinning, or no airflow at all. Schedule a service appointment with an HVAC company to diagnose the issue. It can determine if the fan motor needs oil, replacement fan blades, a new belt, or if you must replace the motor.
Some people using window ACs face the issue of water dripping from the unit inside their homes. This problem could be due to the incorrect angle of installation. Water drips from the AC due to condensation, but you can expect it to do so through the drain pipe outside your window. If the AC is installed with a slope toward the front end instead of the rear end, you may experience leaking indoors.
You can stop the water from dripping on the inside by reinstalling your AC. Doing this may require professional help if you’re unsure how to do it correctly. The window kit should angle the AC system slightly downward outside so condensation runs out the back through the drain pipe. Make sure the back of the unit tilts down just a bit.
Another cause could be a clogged drain pipe. Use a stiff wire to clear any obstructions in the drain line so water can flow freely. Pouring vinegar and water through the drain monthly can help prevent buildup.
Your window AC unit may develop a leak in the evaporator coil, condenser, compressor, or refrigerant lines. When the refrigerant leaks, your window unit may blow warm air, not turn on at all, or turn on and off frequently. In some cases, it can also form a layer of ice.
Unfortunately, there is not much you can do yourself to fix a refrigerant leak. Usually, you’ll need to replace the entire air conditioner. That said, if the leak is in the refrigerant tubing, an EPA-certified HVAC technician can fix it and refill the AC unit with refrigerant.
Why You Need Annual Tune-Ups
While regular maintenance every few months is important for your window AC unit, I and all HVAC pros, recommend an annual tune-up by a professional to keep your system running efficiently for its entire life span.
Air conditioners have complex working components, and you can’t fix everything on your own. If you can’t get your window AC unit to work after cleaning the filter, checking the power connection, and clearing the condensate drain line, it’s time to call in an HVAC pro for help. Additionally, annual tune-ups by an HVAC technician provide thorough inspection and maintenance to keep your AC running efficiently.
The technician will check refrigerant levels, clean coils, lubricate parts, inspect drain lines, and ensure proper airflow. They can find minor problems before more significant issues occur. Tune-ups cost $80 to $150, but save money in the long run by identifying issues early.
You can find an independent HVAC technician or hire a company near you by typing in your ZIP code using the Same Day Pros app.
So, Is a Window Air Conditioner the Right Choice?
For cooling a single room, a window AC offers an affordable and easy-to-install option without occupying interior floor space. If you perform routine maintenance, you can prevent breakdowns caused by dirty air filters, clogged drain lines, broken fan motors, and refrigerant leaks. While central air conditioning cools an entire home evenly, a window unit focuses on the room you need. Floor air conditioners and ductless air conditioners are other great options for cooling single rooms or smaller spaces.
That said, window units come with some downsides. Their efficiency is lower than central AC units, noise levels can be disruptive, and installation requires a window. Plus, some homeowners dislike the look of an AC unit sticking out of a window and how it blocks the view outside.
Overall, a window air conditioner is ideal for supplemental cooling if you don’t want or can’t install central air conditioning. Just be prepared for some maintenance and lower efficiency compared to a central system. If you’re shopping for a new window AC, read all about the best window air conditioners on the market.
FAQs About Window Air Conditioners
How Long Do Window Air Conditioners Last?
With proper maintenance, a window AC typically lasts eight to 10 years. Units that stay in place year-round tend to have a shorter life span of five to six years.
What Are the Disadvantages of Window Air Conditioners?
Disadvantages include lower efficiency than central air, disruptive noise, the need for a window, and not cooling multiple rooms evenly. They are also a pain to remove before winter and install again for summer.
Should I Get a Window AC or Portable AC?
Window units don’t take up any floor space like portable ones do. However, portable AC units look more appealing and don’t block your view out of your window. Consider your space and needs.
How Much Electricity Does a Window AC Use?
Window units use 500 to 1,500 watts on average. A 10,000-BTU window AC running five hours daily costs around $40 to $75 monthly. Get an ENERGY STAR-rated unit for maximum efficiency.
What Size Window AC Do I Need?
Many companies size window AC units based on room square footage, but the best way to properly size any HVAC system is using ACCA (Air Conditioning Contractors of America) Manual J heat gain load calculations — the industry standard for system sizing, required by code in many locations across the United States.
