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Troubleshooting Common AC Problems: A Homeowner's Guide

Get your home's air conditioning back up and running with these easy-to-follow troubleshooting tips and know when to call in the pros.

Your air conditioner keeps your home cool and comfortable all summer long - until it doesn't. We've all been there - walking inside after a hot day to find your AC just isn't working like it should. Before you start sweating and call for service, there are some simple troubleshooting steps you can try first. In this guide, we'll cover some of the most common AC issues and what you can do to get that refreshing cool air flowing again.

The AC Won't Turn On At All

Electrical/Power Issues

]If your AC refuses to power on, start by checking if it's receiving electricity. Make sure the unit is plugged in and no circuits have been tripped. Your outdoor condenser unit may have its own disconnect box - open it up and ensure the safety switch is flipped to "ON."

Thermostat Troubleshooting

Many times, a seemingly dead AC can be revived by resetting the thermostat. Try manually adjusting the temperature setting a few degrees below the current room temperature. If it still doesn't kick on, change the batteries and make sure it has power.

My boss, Bill, learned this the hard way last month when he thought his brand new unit was already busted. Luckily his wife reminded him to check the thermostat - sure enough, it was just out of batteries! Crisis averted with a quick swap. Don't skip this easy first step.

Strange Sounds Coming From the Unit

Loud Grinding or Screeching Noises

If you hear loud grinding, screeching or metal-on-metal noises when the AC starts up, shut it off immediately. This is likely caused by a broken motor bearing or other internal mechanical failure. Letting it run can cause serious (and expensive) damage. This is a job for a professional HVAC technician.

Rattling, Buzzing, Clicking

While not as critical, rattling, buzzing or clicking from the outdoor unit can also indicate an internal problem like loose parts. Try gently clearing any debris from the unit's fans. For persistent noises when the system is on, it's best to have a tech inspect the inner workings.

One summer, my neighbor's AC was making the worst grinding racket every time it fired up. Assuming the worst, he resigned himself to replacing the whole system. As the technician was hauling out the old unit, a stray Frisbee fell out of the fan compartment - turns out a well-aimed toss from his kid was to blame for all that torturous noise!

The AC is On But Not Cooling Properly

Air Flow & Filter Check

If your AC seems to be running but isn't producing much cool air, start by checking the airflow. Ensure supply vents aren't blocked and return air intakes aren't obstructed. Next, replace the air filters. Clogged filters restrict air circulation and make the whole system work harder. For optimum efficiency and cooling power, filters should be changed every 1-3 months.

My dad always reminds me - a fresh air filter makes a huge difference! I used to think he was exaggerating until I experienced the lackluster cooling from a unit with a 6-month-old filter. What a quick fix for better air flow.

Check the Condenser Unit

The outdoor condenser unit is what actually cools the refrigerant, so give it a once over. Make sure it's free of built-up dirt, grass, leaves or other debris blocking airflow. Using a garden hose, gently spray off any accumulation on the fins and clear out the base area around the unit. An obstructed condenser has to work harder to disperse heat, overtaxing the system.

Low Refrigerant Levels

Over time, minute leaks in the copper refrigerant lines can cause levels to drop - resulting in reduced cooling power. While you can't get an accurate reading, if the AC is cooling but struggling to keep up, it may be running low on refrigerant. Have an HVAC tech inspect the refrigerant charge and seal any leaks.

When to Call in a Pro

While DIY troubleshooting can resolve many common AC woes and save you money, some issues are best left to the experts. If any of the following applies, it's time to call Keith Powell Heating and Cooling for professional diagnosis and repair:

  • You've worked through the basics but cooling is still inadequate
  • Strange sounds persist after checking for debris
  • You suspect an electrical/wiring issue (safely hire an electrician first!)
  • The system needs repair parts or refrigerant services

At Keith Powell, our skilled techs can properly pressure test for leaks and recharge refrigerant levels per EPA guidelines. We also offer affordable annual maintenance packages to keep your system clean, lubricated and optimized for peak cooling performance year after year.

When speaking to an HVAC pro, be prepared with details like your AC's make, model, age, and any unusual behavior you've noticed. Key questions might include:

  • How much will a repair cost versus replacing the unit?
  • What are options to improve energy efficiency?
  • Do you offer discounts or financing for system replacements?

The best solutions keep your home comfortable without racking up sky-high energy bills. Trustworthy companies like Keith Powell lay out affordable options upfront so you can make the most cost-effective decision.

Nobody wants to deal with air conditioning issues on a sweltering summer day. But with some simple troubleshooting steps and help from the experts, you can get your AC running like it should. Stay cool, Knoxville!