ac unit
Repairing an air conditioner (AC) condenser typically involves replacing or fixing one or more parts that make up this complex component. Depending on the nature of the problem, the cost can range from $150 to more than $1,000. Homeowners can repair some minor AC condenser issues themselves, while some major issues require a professional to install a completely new AC unit. Below is an in-depth look at AC condensers and how to get them in shape.

On This Page:

  1. What is an AC Condenser?
  2. How an AC Condenser Unit Works
  3. Common AC Condenser Problems
  4. Repair or Replace?
  5. AC Repairs You Can DIY
  6. Cost to Hire a Pro
  7. Conclusion

What is an AC Condenser?

An AC unit has several main components, including a condenser, a compressor, an evaporator and an expansion valve. The AC condenser is the exterior component of the overall AC system, which means you’ll typically find it outside your home. This part plays an important role in heat transfer and is responsible for the AC unit’s cooling process.

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How an AC Condenser Unit Works

Essentially, an AC condenser converts refrigerant gas into liquid form. It does this by facilitating a state change and cooling the gas with the help of a high-powered fan that passes air over a condensing coil. Once cooled, the liquid refrigerant moves along within the AC system to cool the building’s interior.

Because the condenser and the compressor sound similar, homeowners sometimes confuse these two components. They have very different functions, though. The compressor serves as the heart of the AC unit, pumping pressurized gaseous refrigerant to the unit’s evaporator.

All of an AC unit’s parts work together seamlessly to make this complex machine function.

  • First, the compressor does its part to pressurize refrigerant into a gas.
  • Next, that gas enters the condenser, where it’s converted to a liquid and transferred to the AC unit’s evaporator.
  • There, the refrigerant is blown into the interior of a home, office or other structure, where it absorbs the excess heat in the air. The AC cycle starts all over again as the unit’s refrigerant heats up to become a gas.

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Common AC Condenser Problems

Though the AC condenser is considered a single component, it’s made up of several parts. The AC condenser’s coil, motor, fans, tubes and circuit board can all fail individually or together. They can also fail suddenly or slowly over a long period. Here are some of the most common problems you’ll run into with an AC condenser.

Dirty Component

Because most home AC units’ condensers reside outside, it’s not unusual for the condenser or some of its parts to attract dirt and debris. It’s also relatively common for grass, brush and other plant matter to grow around the unit, surrounding it and preventing it from working properly. If you notice that your AC unit isn’t cooling your home like it should, first check the condenser’s exterior condition to be sure it’s reasonably clean.


Leaks within faulty tubes and seals are common reasons for condenser failure. The component’s tubes can rupture, get punctured or become brittle and break apart. The seals can wear and break down after extensive use. While these parts can fail as the result of an impact, they typically fail due to regular, ongoing wear.

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Particles and debris can accumulate within the AC unit and lead to blockages, ultimately causing condenser failure. While some of this debris might be external, it’s more often the result of metal particles that have flaked off the condenser itself. This essentially leads to the condenser self-destructing, and it’s usually the result of age or poor maintenance.

Bad Run Capacitor

The AC condenser’s run capacitors energize the component’s fan motors. A run capacitor that’s gone bad will cause a jump but won’t actually start the motor. There’s a good chance the condenser’s run capacitor is bad when the motor won’t start anymore. Run capacitors can decline gradually or go out suddenly.

Bad Condenser Relay Switch

The condenser fan relay switch is the critical part of the condenser that switches the fan on and off when you turn the AC unit on and off. Without a functioning fan, the condenser and the larger AC unit won’t work effectively.

Faulty Control Board

The condenser’s control board is the circuit board that communicates between the various parts. When the control board is faulty, communication breaks down. Critical parts like the fan motor and the coil don’t function or switch on or off like they should, which compromises the entire component.

Damaged Coil

A damaged coil is one of the most severe problems an AC condenser can have. A variety of things, including debris, impact and corrosion, can damage a coil. Because this is such an integral part of the overall component, a damaged coil instantly compromises the entire AC unit.

Burnt Motor

When the condenser’s motor starts to go, it’s often a gradual process. Instead of flaming out in a dramatic fashion, the fan motor will start to move more slowly, working much less effectively over time. Condenser motors typically fail as the result of stress and poor maintenance over a long period.

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Repair or Replace?

When to Repair

  • Dirty Condenser: This is one of the easiest repairs. If you discover that the area around your condenser is overgrown or that your condenser is covered in dirt or plant matter, simply trim the grass or brush around the unit and continue to provide regular maintenance. If debris is on or around the condenser, clean the area and remove anything that’s blocking or interfering with moving parts.
  • Bad Run Capacitor: This is usually an easy repair. Once you’ve confirmed that the run capacitor is the cause of the problem, you can typically swap in a new part.
  • Bad Condenser Relay Switch: This is also a simple repair and a relatively insignificant problem in the grand scheme of things. When the condenser fan relay switch goes bad, simply replace the relay.
  • Faulty Control Board: When the condenser’s control board starts to malfunction, you’ll need to replace it with a new one. Make sure that any new circuit board you introduce works well with the condenser’s existing parts.
  • Burnt Motor: If the motor goes, you typically don’t have any choice other than replacing it with a new one. Be sure to swap it for an identical part if possible, because introducing different specifications into an AC unit can be disastrous. If the specs don’t match, you might have to replace the entire unit.
  • Damaged Coil: When your condenser coil is on the fritz, first do some basic maintenance by cleaning the coil. If that doesn’t fix the problem, you’ll have no choice but to replace it. Because this repair requires significant time and labor, it’s typically an expensive fix. If your condenser coil is out of warranty, it’s best to consider just replacing the entire AC unit.

When to Replace

When you’re determining whether to repair or replace your condenser, consider your AC unit’s age. Technological advances for AC units roll out every few years, so you might benefit from simply replacing the condenser or the entire unit if it’s more than 10 years old. Even if a repair would fix the problem, installing a newer and more efficient unit could save you money in the long run.

  • Leaks: This might seem like a minor problem, but it’s actually a major one. It’s not possible to replace condenser tubes or seals, so when your condenser starts to leak, you’ll need to replace the entire component.
  • Blockage: A blockage also signals a major problem. If you encounter a blockage within your AC system, it’s time to replace the condenser. Unfortunately, depending on the damage, you’ll also need to replace several other expensive parts, such as the ac compressor cost. This is a good time to consider simply replacing the entire AC unit if possible.

When to Consider Other Solutions

There’s much more to an efficient and fully functional AC unit than just the condenser, compressor, evaporator or other primary components. You might notice that your home doesn’t cool properly even when the AC unit runs smoothly. If this happens, consider other factors within the AC system.

  • The ductwork inside your home will compromise your AC unit’s cooling capabilities if it’s leaky, damaged or simply outdated.
  • Other common efficiency problems result from invisible gaps and leaks in the walls and windows of your home. When cool air sneaks out of your home in the summer and hot air leaks out during the winter, you’re almost certainly dealing with a greater efficiency problem. If you suspect this is an issue, partner with a professional to do a walk-through and make sure your home doesn’t have excessive gaps or leaks.
  • Make sure your AC unit is the right size for your home. If it’s too small to cool your house, then you’re likely to have continual problems with stress and overuse. However, don’t overcompensate by installing an AC unit that’s too large for your home. Oversized AC units tend to complete cooling cycles too quickly, leading to the relays switching the condenser fan motor off and on frequently. This wears out the motor, and your condenser, quickly.

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AC Repairs You Can DIY

Most AC condenser issues require professional help, but with a little know-how, the average homeowner can tackle basic condenser maintenance.

  • Clear debris: For best results, clear plant matter and debris from the condenser fan area monthly. Do it more often if you observe a debris problem or if your yard has significant overgrowth.
  • Clean fan blades: This is something you should do before you turn on the AC unit each summer, because the fan naturally pulls in dust and debris. Before you begin, switch off the power to your AC unit to avoid damage or injury. Gently clean the fan blades by vacuuming them with a soft brush, taking care not to bend or damage the blades.
  • Check fan blades: The condenser fan won’t function properly if it’s not positioned correctly. Examine the fan to make sure the blades don’t strike stationary parts of the condenser or otherwise malfunction.
  • Lubricate the motor: It’s important to do this once a year to make sure your condenser motor runs smoothly throughout the summer. Be sure to use basic electric motor oil for lubrication.
  • Shade the condenser: If your AC condenser is in direct sunlight all summer, it might see more stress and wear than necessary. Don’t risk overheating. Consider shading the condenser without blocking or obstructing it.
  • Test the condenser: Check to see that your maintenance was successful by switching the power on and setting the AC unit to run. Observe the condenser closely to watch for leaks or other signs of a problem. Confirm that the condenser and AC unit are working normally, and call a professional if you detect any other problems.

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Cost to Hire a Pro

The average cost for an AC unit repair is about $200 to $600 per fix. Some homeowners spend as little as $100 for basic maintenance or a quick part swap, while others spend as much as $1,000 for more complex jobs and parts.

No matter how extensive the work, make sure the contractor you hire offers a warranty lasting for at least one year. This is important for guaranteeing the contractor’s work and ensuring you’re getting what you’ve paid for.

Dirty Component

Cleaning and maintaining the condenser and the surrounding area typically doesn’t require parts. Most contractors will charge for labor only, which starts at about $50 per hour.


A leaking condenser requires a complete replacement. The average cost for a new condenser is about $1,750.


It’s possible to keep an AC unit running despite a blockage, but a repair like this requires extensive work and multiple parts. Plan on replacing the condenser, compressor, receiver dryer and tubes, or simply replace the entire AC unit. A new condenser typically costs about $1,750 to replace. How much does an ac compressor cost? While it can vary, most spend about $2,000. Depending on the size of your home, a new AC unit might be less expensive than replacing these major components.

Bad Run Capacitor

This is one of the cheaper repairs you can have done. Depending on where you live, you can typically pay a pro $150 to $275 to install a new run capacitor for you, which will get your fan moving and your condenser working again.

Bad Condenser Relay Switch

This is another inexpensive AC condenser repair. A professional will charge an average of $175 to $275, depending on your location.

Faulty Control Board

This typically costs $150 to $400 to fix, depending on the AC unit model and the control board’s complexity.

Damaged Coil

A coil replacement is one of the most significant AC condenser repairs. Not only is this a very expensive part, but some coils can also be hard to get, depending on the model. Replacing the coil also requires extensive labor. The condenser coil usually costs about $400 to $1,200 to replace.

Burnt Motor

Because the condenser motor is a complicated and important part, it can be somewhat expensive to repair or reinstall. You can expect to pay at least $350 to $575 to replace a burned-out motor, but keep in mind that you’ll need to replace the run capacitor as well, which usually costs an extra $150 to $275. Also note that some motors are much more expensive than others. High-efficiency condensers might come with two-stage motors, which can be costly.

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To keep your AC condenser running at top efficiency, perform routine and standard maintenance. If you’re a DIY enthusiast and familiar with the condenser’s many parts, it might be worthwhile to take on basic repairs as they arise. Because many condenser equipment failures require replacing parts or the complete unit, though, don’t hesitate to call in an AC pro for help.

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  1. Lillian Schaeffer, March 7:

    This is some great information, and I appreciate your suggestion to have regular maintenance done on your AC to keep it running well. My husband and I just moved into our first house, so we’ve never had to care for an air conditioning unit before. We’ll definitely look into having a professional come and do routine maintenance to avoid potential problems. Thanks for the great post!

  2. Angie, May 15:

    Carrier heatpump / aircondition all in one unit. I can put my fan to on and the fan will blow. When I turn on my heat or air and the switch is in auto I get no air flow but the unit outside is running . Also if I do have the switch to on and the air is flowing I get no heat or cooling, just air.

  3. Cecilier, June 22:

    i would like to ask how much will charge for the 4 ton, tran brand for evaporator coil replacement due to leaking as per one of the air guy evaluation.


  4. Ed Johnson, July 7:

    My fan motor quit working and was replaced with a generic fan motor. The fan motor will run for a while but will heat up quickly and shut down. After it cools off it will run again. I am still getting cool air in the house when it runs. The guy who replaced the fan motor is now telling me that it is the condenser causing this to happen. Could the condenser cause this?

  5. Nancy Kindness, October 7:

    The coil is leaking on my 3 ton airconditioner. It is recommended I change it. Fluid has been added twice – in May and late September. Can anyone tell me the cost to replace it in Sacramento CA. Part and Labor.
    Thank you

  6. Berle Hopkins, June 4:

    Trying to get a fair price to repair a Trane heatpump evaporator. Get quotes from $1800 to $3000 using manufacturer’s parts. Crazy difference in estimates. System only 5 yr old

  7. Sherry, June 20:

    Will a bad condenser cause your breaker to switch off

  8. Johnnie, July 18:

    My a/c unit was installed 7/2014 when the house was built problems first year from drain line,capacitor,condenser coil, the unit have been draining water inside my home since 2014.

  9. Stanley Stone, July 24:

    I’m afraid the wording is a bit off here–the condensed refrigerant is not “blown into the interior of a home,…” YIKES! The condensed refrigerant goes to the expansion valve where it expands, cools and absorbs heat from the interior of the building through the evaporator coils.

    “All of an AC unit’s parts work together seamlessly to make this complex machine function.

    First, the compressor does its part to pressurize refrigerant into a gas.
    Next, that gas enters the condenser, where it’s converted to a liquid and transferred to the AC unit’s evaporator.
    There, the refrigerant is blown into the interior of a home, office or other structure, where it absorbs the excess heat in the air. The AC cycle starts all over again as the unit’s refrigerant heats up to become a gas.”

  10. Amk, August 10:

    Your prices are low on this website. Ive been doing this 6 years and over the six years we have been rising in price a lot due to many factors. Aluminum went up, copper is expensive, and the industry is running out of qualified workers.

  11. Greg, August 25:

    How much should it cost to replace a drier with leaking piping on a Carrier heat pump?

  12. Ron, November 16:

    Lennox, 3 year old system, hard start relay blew and damaged the condenser coil. $270 for new relay, coil covered under warranty, $1100 in labor to replace coil.

  13. Lee, November 27:

    I want to remove my condenser unit and I notice a wire connection and a pipe which I assume is the refrigerant. What cautions do I need to know so no harm is done?

  14. John, March 14:

    I have been told I have a leak in my ac coil and would need to be replaced. It is under warranty however, have been told by technician there is a warranty fee of $100 even thou it is locally in stock. This does not sound right to me. Another question is once the original coil is replaced , do they need to take it or can I stay with it?

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