What Is Air Conditioner Repair?

Written By Lester Mclaughlin
Updated On

Are you wondering how to learn about air conditioning repair?

You’ve come to the right place!

In this Blue National HVAC guide, you’ll learn:

  • The basics of how an air conditioner works
  • The different types of air conditioning repair
  • When to hire a professional AC repair technician
What Is Air Conditioner Repair?

And much more!

So, if you’re looking for information on air conditioning repair, keep reading our detailed guide below to get answers to all of your questions!

What Is Air Conditioning?

To understand air conditioning repair, you should first know the basic principles of air conditioners. Air conditioners range from central air systems, window air conditioners, ductless mini-split heat pumps, and air-source heat pumps.

You probably think of air conditioning as providing cool air into a room or a vehicle. “Crank up the AC, it’s hot” is too familiar of a saying in the dead of summer. 

While air conditioners do lower the temperature, the process is a lot more complex than just adding cool air. In actuality, air conditioners remove heat from the air and provide that cooler air into a building.

Air conditioners or AC units, for short, remove heat from the air through a process called the vapor-compression refrigeration process. 

Vapor-compression refrigeration is the same concept that chills your food in your refrigerator and your freezer. If you ever thought a building was as cold as a freezer, you already understand that AC and refrigeration work on the same concept. 

Vapor-Compression Refrigeration in Air Conditioning

Vapor-compression refrigeration is the most common technology behind air conditioners. When an AC unit needs repairs, this is usually the type of unit that needs to be fixed. 

The components of air conditioning systems are connected together in a closed-loop with refrigeration lines. The refrigeration lines contain liquid and gaseous refrigerants depending on the stage, which corresponds with the four major components: 


The saturated vapor refrigerant is sucked through the compressor and compressed to a higher pressure. This compression makes the vapor very hot too. The high-temperature vapor becomes superheated vapor and can then move to the condenser. 


When the superheated vapor enters the condenser, it is cooled by either water or by air flowing across coils or tubes filled with the vapor. The refrigerant’s heat is removed from the vapor, and the vapor now condenses to a pressurized, saturated liquid. 

Thermal Expansion Valve

The next stop for the saturated liquid refrigerant in the closed-loop system is the expansion valve. The thermal expansion valve provides a sudden reduction in pressure to the liquid, resulting in it evaporating and rapidly lowering in temperature. 

This now cold refrigerant is passed on to the evaporator. 


The evaporator is essentially a reversed condenser, the cold refrigerant is passed through coils, and warm air is blown across the cold refrigerant-filled coils. 

As the warm air passes across the cold coils, the heat is removed from the air and is transferred to the refrigerant. The now colder air is provided into the building to cool it, and the now-warm refrigerant is passed along to the compressor to repeat the cycle. 

What Do You Need To Know About AC Repair?

If an AC unit needs repair, it’s usually because of issues with the compressor, condenser, thermal expansion valve, or evaporator. 

Sometimes issues come up because of refrigerant leaks. If your air conditioner leaks refrigerant, the vapor-compression cycle won’t work. AC units are designed to have a certain amount of “charge” or refrigerant to meet your house’s load requirement. 

Whatever the problem is with your air conditioner, it is vital to get it repaired as soon as you can. 

A broken air conditioner can be a fire hazard- the National Fire Protection Association estimated that over 1,300 home fires were caused by air conditioners between 2012-2016. Using an AC unit safely and getting proper maintenance and repairs is crucial to preventing the disastrous event of a fire. 

Air conditioning units without regular maintenance can also negatively affect your health. 

If condensation occurs in your ductwork, it could produce mold and eventually get to the point where your respiratory system is affected. To better protect your health, make sure you routinely change your filter as it prevents allergens, air pollutants, and other outdoor irritants from entering your home. 

Air Conditioner Troubleshooting

You can determine if you need your AC unit repaired by checking for simple things that range from obvious to not apparent (unless you’re looking for it.) 

First things first! Make sure your thermostat is set to cool or is in cooling mode! You’d be surprised how many people accidentally have their thermostat set to heat- and end up paying for a service call just to have a switch flipped from “heat” to “cool.”

It’s Too Warm in Your House

If you start to sweat and notice that your thermostat is reading higher than the setpoint and won’t go down, you have an AC problem. Check to see if there is warm air coming through your ducts. 

If there is warm airflow, it is likely an issue with your compressor, restricted airflow, or a refrigerant problem. 

AC Unit Turning On and Off Constantly

While you should expect your air conditioning to turn on and off and not run 100% of the day, it should not constantly turn on and off. If you notice your AC unit having frequent power on/off cycles, you may require a repair, tune-up, or a replacement. 

No Power 

When your AC unit refuses to turn on will be one of the more apparent issues that requires a repair. 

Unpleasant Smells

If you’re noticing foul smells and odors coming through your ductwork, that could be a sign of an air conditioning issue. If your AC unit is creating too much condensation, water can condense inside your ductwork, providing a space where mildew and mold can grow. 

If the ductwork in your house is smelly funky, check your AC unit now! It could be mold or mildew in your ductwork, yuck!

High humidity and Leaks

AC units are designed to provide moderate and consistent humidity levels to your home. If you notice a sudden change in humidity issues, that could be a tell-tale sign of an air conditioning issue that you need to address. 

What Are The Different Types of Air Conditioning Repair?

The type of air conditioning repair you need depends on the AC unit component that is having issues. 

A seasoned HVAC repair technician can quickly diagnose issues with AC units within minutes and determine if it warrants a component repair or replacement or the replacement of the entire AC unit. 

Air Conditioner Compressor Repair

A common issue with the compressor is when the fan motor stops working. When the fan breaks, there is nothing to blow the warm air across the cold condenser coils. This issue interrupts the heat transfer and prevents cold air from entering your home. 

Fan or blower problems could lead to more significant issues – if the fan motor is broken, making the heat transfer stop, your compressor can overheat and get damaged itself. 

If the fan is broken, an air conditioner repair specialist can replace it or fix the issue to get it workly properly. It is crucial to get this repair right away so further, more expensive damage to the compressor doesn’t happen. 

If your compressor does get damaged, it is often best and easiest to replace it instead of repairing the damaged unit. 

Air Conditioning Condenser Coil Repair 

If your condenser coils get too cold and build up too much moisture, they can freeze over entirely. Instead of having coils that air can freely pass over, the air will hit an ice wall. 

Frozen condenser coils on the outdoor unit can be caused by poor system airflow, from either blocked return air ducts or dirty air filters. An HVAC repair technician can properly thaw your frozen coils and fix the issue that caused it in the first place. 

Air Conditioner Evaporator Coil Repair 

The most common problem with evaporator coils in AC units is leakages. Actually, refrigerant leaks occur most commonly on the indoor evaporator coils compared to the outdoor condenser coils. 

When the refrigerant leaks, the AC unit’s heat transfer will be slowed and perhaps completely halted if enough leaks out. Unfortunately, repairs on the evaporator coils are nearly impossible since there are so many and they are so small.

Since evaporator coils cannot be repaired, the evaporator will have to be replaced. HVAC technicians can diagnose this issue with a refrigerant leak detector and arrange a replacement. 

Refrigerant Line Leaks

Sometimes the refrigerant lines connecting the condenser to the evaporator wear down and start to leak. This could be caused by years of wear and tear, abrasions, or any number of impacts. 

An AC repair specialist can quickly identify leaks on the refrigerant lines. They will repair or replace the line and recharge the AC system with refrigerant. 

Condensate Line Clog

Condensation is a natural product of the AC unit’s cooling process. The condensation (of liquid water) is diverted away from the AC unit in regular operation. 

If there’s too much condensation or if the drain line is clogged, the excess condensation can raise the humidity level in your home. It may also leak into other components of the air conditioner and damage them. 

If you’re up for a new challenge, you can clean the AC drain line yourself or rely on an HVAC technician to help fix the issue. 

Preventative Maintenance of AC Units

If you want to lessen the number of repairs needed on your air conditioning system, you should do routine AC maintenance

Preventative maintenance on your AC unit prevents you from having issues that require repairs in the future. By doing minor and less costly maintenance now, you’ll save money in the future by not having to pay for repair or replacements!

There are AC maintenance steps you can do yourself, like cleaning your exterior AC condenser unit, cleaning indoor registers and vents, changing your air filter (every 30 to 90 days). 

However, since AC units are complicated mechanical systems, you should hire an HVAC contractor to perform more extensive maintenance checks. They can inspect for leaks, lubricate moving parts, straighten condenser coils, and do much more to optimize your AC unit’s performance. 

When Should You Hire A Professional To Fix Air Conditioners?

If you are not an HVAC technician or AC unit repair specialist yourself, chances are you cannot fix your AC system yourself. If you are having an issue with your air conditioner, you should shut it off entirely and call an HVAC contractor to schedule a visit. 

You might have to go to your electrical breaker box to shut it “off.” The reason you should turn it off to prevent additional damage from occurring. Faulty components can cause more severe damage and lead to more expensive repairs. 

How Much Does Air Conditioning Repair Cost?

Air conditioning repair costs can vary depending on the air conditioner brand, the type of system (central air or window air conditioner), and the component that needs to be replaced. 

However, a faulty cooling system can increase your energy bills, so fixing it can provide immediate cost savings on your energy bill. 

On an average basis, you can expect to pay around $250-$400 for a typical repair of your AC unit. Simple repairs will cost less, but if it’s a major component like a condenser coil, you’ll be paying a lot more. 

Condenser Repairs

Compared to other components of an AC unit, condenser repairs are on the lower end. Replacement of condensate drain tubes ranges from $20-$35, while drain pans replacement costs $275-$600. 

To replace a complete condensate drain pump, you can expect to pay between $250 and $500. To flush your drain line, you’ll likely have to cough up $90-$300. Lastly, to replace the entire condenser coil- the price will range from $2,000 to $3,000 or more.

Other Repairs

To repair a typical refrigerant leak issue, the price will be about $250 to $1,600 to repair the coolant leak, then another $300 to $800 to recharge the refrigerant. 

If your compressor breaks down, replacements cost just over $2,000, and outdoor motor fans typically require $240 to $700 to repair. To repair and replace electrical components like relays, fuses, capacitors, or circuit breakers, the costs can range from $100 to $300. 

To get accurate repair and replacement cost estimates, homeowners can get quotes from a few HVAC contractors in their local area. 

What Should You Look For In An Air Conditioning Repair Specialist?

Finding the best HVAC contractor or AC service technician is not a task homeowners should take lightly. If the technician fails to do the repair correctly, they could cause further damage, perhaps requiring a brand new unit. That is why you should seek out experts for your air conditioner repair. 

Selecting the “right” AC repair service company for you is not an easy decision; you can decide with your gut feeling and factor in some of your own research and information they provide you. 


If the AC repair service is responsive, chances are they want your business and are not so busy where you’ll be waiting hours for a late maintenance specialist. If they are responsive, they will be able to assist you better if you ever have an AC emergency. 


Determine if the AC repair contractor has experience. You should be able to determine how long they’ve been in business, how many contractors they employ, and the brands they specialize in on their website. 

Alternatively, you can call in and discuss their experience levels over the phone. 

Customer Service

Make sure your potential contractor is friendly and considerate of your time. Ideally, you probably don’t want to work with rude or disrespectful people, so run like the wind if you ever experience negativity. 

Financing Options

If you’re expecting a more significant repair or complete system replacement, you may be due for a hefty, unexpected bill. If you don’t have the cash on hand to pay the full price, it could be beneficial if the contractor has financing options. 

Financing would allow you to make monthly payments for your repair or replacement. 


Chances are your friends and family have needed air conditioner repair or replacement services in the past. Look for references from your closest confidants on which contractors to check out and, more importantly, which ones to avoid. 

You can also seek out Better Business Bureau ratings and online reviews for even more details. 

Fair Prices

Lastly, you want to make sure the HVAC contractor/AC repair technician gives you a fair price. You should be able to determine this from online reviews, and if you want to take an extra step- you can call 2-3 more contractors to compare prices. 

Meet Your HVAC Expert

Lester Mclaughlin

HVAC systems are highly technical and often is the most misunderstood part of the house. From ductwork to heat pumps, I've been exposed to all sorts of issues facing homeowners. It really irks me when a homeowner is given bad advice like refilling freon vs fixing a leak in the system. I'm here to help our website readers with their heating and a/c problems.
More HVAC Guides
Signs Your AC May Need A Refrigerant (Freon) Charge
What Is Refrigerant & How Does it Help AC
Are Variable Speed AC Worth The Cost
Air Filter Vs. Air Purifier
The Humidity & Temperature In Home

Request A Free Quote

By submitting your info on this form, you are agreeing to be contacted regarding your service request by means of telephone, email, or text including using pre-recorded or auto dialed phone calls or text messages to the phone number you have provided, including your wireless number, if provided. Consent to contact doesn’t require you to purchase service. Please note you may be matched to one of our trusted partners such as Craft Jack or Angi. By using this service, you agree to our Terms Of Service as well as to Angi Terms of Service and Privacy Policy.


Fast Free Quotes
Expert HVAC Technicians
Punctual Service
Best Pricing
Simple Payment Plans
Satisfaction Guarantee




emergency repair service


We have a project manager on call 24/7/365 to dispatch our professionals. That means whether you need service on weekends, holidays, or evenings, we’re there for you when you need us most!


Blue National HVAC delivers rapid and reliable service for all your heating and cooling equipment at the simple click of a button. Our friendly and professional team has decades of experience and is ready to help solve your HVAC problem in no time at all!

Contact Us | Terms and Conditions | Privacy Policy