15 Most Common AC Repairs


These are some frequent problems that people experience with their air conditioning unit. We’ll give you some tips on what might be causing the issues, and how to make sure the problem gets fixed.

Freon Leak & Recharge

R-22 Freon tank

Freon is just another name for refrigerant – it absorbs heat inside your home and expels it outdoors.

– Common Causes of Freon Leaks

Leaks can occur a few different ways.

  1. If the AC system wasn’t properly installed, contaminants could have corroded the pipes and created tiny holes for the Freon to slowly leak.
  2. If the systems pipes weren’t properly soldered together, small leaks can occur.
  3. Poor maintenance, like a technician putting too much refrigerant in the system, could also result in a leak due to too much pressure.
  4. A leak could come from someone damaging the outdoor condenser coil. A lawnmower that throws rocks or metal into the condenser coil could damage one of those tiny pipes and cause a leak.

– Fixing Leaks & Recharging

Sometimes, you can recharge your system by adding back Freon, but it isn’t always possible or cost-effective. For older R-12 units, you’re not allowed to add refrigerant back to a leaking system, and the cost of R-12 is very high. Your best course of action is to get the leak repaired, and then have the system properly decontaminated and recharged.

For More Information

Check out our video blog, AC Maintenance: Freon Charge

Compressor Replacement

HVAC Compressor

The compressor is like the heart of your AC system, so it’s very important.

– Common Causes of Compressor Failure

Compressors can fail for a variety of reasons:

  1. Poor decontamination during install could leave contaminants that corrode the compressor from the inside out.
  2. Poor soldering could have left tiny solder particles inside the pipes. Once they get to the compressor, they can do tremendous damage.
  3. If the unit is unlevel, the compressor oil may not be able to circulate properly. Just like if your car runs low on oil, this causes the compressor to wear out over time.
  4. Lower-quality AC systems often cut corners by using single-speed compressors. They’re cheap to buy, but they wear out sooner.
  5. Poor maintenance could mean putting too much refrigerant in the system. This could cause very high and damaging pressure that wears out the compressor.
  6. Freon leaks could cause the compressor to overwork, leading to a shorter lifespan.
  7. Dirty coils could keep the refrigerant from evaporating or condensing properly, which may possibly lead to catastrophic failure.
  8. Blocked lines can cause the compressor to overwork and die sooner than expected.

– Replacing a Compressor

Compressors are often one of the most expensive repairs, so if your unit is old, you should consider replacing the AC system. If your unit is new and under warranty, we can discuss options to possibly get replacement parts for free. Ultimately, the compressor must be replaced properly, and the system must be cleaned, decontaminated, and tested to ensure the new compressor is working efficiently.

For More Information

Check out our Video Blog AC Maintenance: Compressor PSI

Thermostat Installation

wall mounted thermostat

Though not a repair, thermostat replacement and installation is becoming quite common.
The thermostat is like the ignition switch on a car, so you absolutely need it.

– Reasons to Replace a Thermostat

  1. Thermostats get old and eventually break or just aren’t accurate.
  2. Newer, programmable thermostats or smart thermostats may actually save you money when properly used.
  3. Older thermostats must be adjusted at the wall. Newer thermostats can be controlled from your mobile phone – so you’ll never forget to turn off the AC while on vacation!

– Options for Replacing a Thermostat

thermostat digital display

If your thermostat goes belly up, it must be replaced. You can go with a cheap bimetal, or a more expensive programmable or smart thermostat.

  1. Bimetals usually don’t require batteries and are simple to operate – great for people who don’t like a lot of technology.
  2. Programmable thermostats require batteries and are a bit more complex, but most of them can easily be programmed to a schedule.
  3. Smart thermostats try to learn your habits and adjust temperatures accordingly. This doesn’t mean they’re the most energy-efficient, but they usually have really convenient apps you can use to control them from your phone.

Watch to Learn More

Check out our video on thermostat maintenance:

Thermostat thumbnail play button

Thermostat Repair

a digital thermostat attached to a wall

Thermostats control your AC system to keep your home at a set temperature. Sometimes you can repair them; other times, you should just replace them.

– Reasons for Thermostat Failure

  1. They get old and inaccurate.
  2. Wiring or electrical issues can damage a thermostat (and don’t rule out a lighting strike).
  3. Some newer ones have batteries. If the batteries die, the thermostat may stop working. You should be able to replace the batteries yourself, but if you need help, just call us.

– Tips for Thermostat Repair

  1. If it’s an old bimetal or electric thermostat, you’ll probably just have to replace it.
  2. If it’s a newer programmable thermostat, it may still be under warranty. In that case, we may be able to get parts or a replacement for free.
  3. If it’s a smart thermostat, some have decent warranties so you can get them exchanged. But you may be without a working AC for a few days until you get the replacement.

Evaporator Coil Repair

HVAC Evaporator Coil

The evaporator coil sits in the air handler in your home and cools the air inside. Here are a few reasons it may fail:

– Common Reasons for Evaporator Coil Failure

  1. Corrosion from moisture is very common on older copper coil systems. The root cause could be too much moisture in the air handler, age, or the condensate pan, line, or pump.
  2. Contaminants in the lines during installation can corrode the evaporator coil from the inside-out.
  3. Contaminants can block lines, making the evaporator run less efficiently.
  4. A dirty evaporator coil keeps it from effectively moving and cooling air.
  5. Freon leaks can cause ice buildup on the coil, which can then lead to corrosion or other damage.

– Repairing the Evaporator Coil

Unfortunately, the only solution is to completely replace the coil. If your system is newer, this may be the best option. But if your system is older, you should seriously consider upgrading to a more efficient system.

For More Information

Check out our Video Blog AC Maintenance: Evaporator Coil

Condenser Coil Repair

Condenser Coil HVAC repair

The condenser coil helps the refrigerant expel heat outdoors after it has absorbed that heat from inside. So yeah, it’s super important.

– Reasons for Condenser Coil Repair

  1. Contaminants left during installation can corrode the coil.
  2. Lower-quality AC systems use older fin designs that have a lot of solder connections, and each solder is a place for potential leaks.
  3. Poor maintenance could mean putting too much or too little refrigerant in the system. This could cause damaging pressure changes.
  4. Dirty coils can block airflow – this is very common since condenser coils sit outside.
  5. Blocked lines from contaminants can ruin a condenser.
  6. Damaged fins or punctures can lead to coil failure (usually it’s a lawnmower that chucked a rock or stick, so be careful mowing your lawn).

– Tips for Condenser Coil Repair

  1. If the system is older, inefficient, or has a low SEER number, consider replacing the system. It may cost more up front, but it could save you more money over the life of the unit.
  2. If it’s a Freon leak due to internal corrosion, or blocked lines, watch out! That corrosion or debris is likely in other parts of your system as well, and can lead to more costly repairs down the line. Consider replacing your system.
  3. If the issue is caused by dirty coils or a poor Freon charge, you need to get a maintenance plan. These are things that need to be checked on an annual basis to prevent damage.
  4. If it’s damaged fins or punctured coils, get a new landscaper! Seriously, never let anyone throw stuff into or at your condenser system.

For More Information

Check out our video blog, AC Maintenance: Condenser Coil

Ductwork Insulation

Ductwork insulation

Ductwork transports the air to and from your AC system. Insulation helps keep the air in the ductwork nice and cool so your air conditioning works effectively.

– Common Ductwork Insulation Problems

  1. Animals like to stay warm, so sometimes they’ll burrow or tear apart ductwork insulation.
  2. Some older systems have very little insulation, or the insulation is falling apart.
  3. Sometimes, ductwork runs in your attic, which gets very hot in the summer. Adding insulation can help keep the air in the ducts cool.

– Adding Insulation

Depending on the type of ductwork you have, adding insulation directly to the ducts may be fine. But if the ductwork is part of an older system, it may be better to just replace the ductwork completely.
You should get estimates for both, as well as information to help you save money on cooling in the summer.

Ductwork Cleaning

Crazy ductwork

For air to flow efficiently in your ductwork, it needs to be unobstructed. As ductwork ages, it accumulates dust and debris that can slow airflow, dirty the system, and cause allergies.

– Reasons to Clean Ductwork

Usually, you don’t need to clean ductwork very often as long as you change filters regularly. But here are some things to consider:

  1. If your system is older, or you live in a rural area with a lot of allergens, or have a lot of dust, you should check your ductwork.
  2. Use a flashlight to look in your supply and return vents. If you can visibly see dirt, dust, mold, mildew, or other debris in your ducts, then you should have them cleaned.

– Best Ways to Clean Ductwork

Cleaning ductwork really depends on what’s making it dirty to begin with. Here are some tips:

  1. If you see mold or mildew, you need to get your system checked immediately. Something is causing high moisture in your ducts, so cleaning won’t solve the root problem. Get the moisture under control and then clean.
  2. If you see dirt or debris, you should get your system checked. Larger particles of dirt and debris shouldn’t be getting into your system. So, you might have a duct leak that needs to be repaired prior to cleaning.
  3. If your system is new and you see a lot of dust or allergens, that can indicate your air filters or return ducts aren’t working properly. Again, get your system checked before cleaning.

Duct Replacement

two large air ducts moving up a wall

Older homes used outdated duct technology – sometimes, just uninsulated tubes and duct tape.

– Reasons to Replace Ductwork

Here are some good reasons you should consider replacing old ducts:

  1. Some rooms are hot while others are cold. This can be caused by improperly balanced or designed ductwork.
  2. Old duct tape slowly loses grip and leaks. Yes, even glorious duct tape eventually fails.
  3. Old duct joints were prone to leaks because some never had mastic.
  4. Old ducts may have less insulation, so the air doesn’t stay cold.

– Tips on Replacing Ductwork

  1. Ductwork has to be designed to balance and maximize airflow. Hire a professional!
  2. Look at potential ENERGY STAR solutions. It may cost more upfront, but you could save a lot of money just by having betterdesigned ducts.
  3. Talk with your AC company. Tell them what you experience in your home – is one room too hot or too cold? Is one vent really noisy?

Duct Repair

ductwork strapped

Ducts can fail pretty easily, but usually, repairs are simple.

– Common Reasons for Duct Repair

  1. Animals love warm materials. So squirrels, rats, and other critters will sometimes burrow through ductwork or steal parts of it.
  2. Water damage can ruin ducts. If your tub or sink leaks, or someone spills enough water down a vent, it can cause some vents to get heavy and collapse. Or worse, get infested with mold or mildew.
  3. Bad installation is sometimes a culprit. Maybe the installer forgot to tighten a collar, or didn’t support a section of duct. And 5 years later, the duct falls apart, leaving you with no cold air.
  4. People can accidentally damage ducts. Sometimes, they put a box in the attic and don’t realize they’ve crushed a duct. Or maybe they’re in the crawlspace and accidently bump a duct loose. It happens!

– How to Properly Repair Ducts

  1. If the duct isn’t damaged, it can usually just be put back together. It may need resealing and some additional parts. Afterwards, it should be tested for airflow.
  2. If the duct is damaged it must be replaced. This can be simple if the run of ductwork is straightforward, without any obstructions. But if there are walls, floors, ceilings, etc. to go through, it can get complex to fix.
  3. If the duct has mold or mildew, the system should be checked. Mold and mildew could have easily circulated through the unit, which is why it’s best to ensure the system is clean before repairing the duct.

Duct Condensation & Mold


Condensation on or in your ducts is never good. That condensation will help breed mold or mildew, which will cause your home to smell, and could possibly cause health risks.

– Reasons for Condensation or Mold in Ducts

  1. If condensation isn’t removed from the air handler, the moisture can then be passed into your supply vents.
  2. Water leaks can also cause these problems. It can be plumbing, roof or wall leaks, or just water spilled into vents.
  3. High humidity around the ducts can cause condensation, like what you’d see in a crawlspace. Usually, this is on the outside of the ductwork, but if there is a leak in the duct, that moisture can infiltrate and create problems.

– Tips for Condensation or Mold

  1. Find the source of moisture. This is a must before repairing the duct.
  2. Have the system checked to ensure no other parts have condensation or mold.
  3. If just a part of the duct is nasty, it may be fine once it’s dried out. But if a lot of the duct is nasty, and smells or discoloration continue, consider new ductwork.

For More Information

Check out our video blog AC Maintenance: Ductwork

Capacitor Replacement

HVAC system Capacitor

Capacitors are awesome! They supply a big jolt of power when your AC system kicks on. Without it, your system won’t run efficiently, or maybe not at all.

– Reasons Capacitors Fail

  1. Age is a big culprit. Over time, they lose capacitance and just can’t supply that jolt of energy.
  2. Heat can also kill a capacitor. This is why many AC systems suddenly stop working on the hottest days of the year.
  3. If your compressor or fan motors are in bad shape, the capacitor may have to overwork to get them started. This can cause the capacitor to die early.

– Tips on Capacitor Replacement

  1. Always ask for Faraday measurements. Seriously, you don’t want to get scammed, so get documentation.
  2. Don’t just replace the capacitor. Make sure other electrical components are tested so you can determine why the capacitor failed.
  3. Get a copy of the system diagnostic with all measurements and technician notes. Again, you don’t want to get scammed.

For More Information

Check out our video blog AC Maintenance: Capacitor

Fan Motor Replacement

Top view of a Condenser Fan

The condenser fan motor circulates air to help expel refrigerant heat outdoors. If this goes, your condenser coil can’t get rid of the heat, and your AC won’t be able to cool effectively.

– Reasons for Fan Motor Failure

  1. Cheaper units have single-speed fan motors, which wear out much faster.
  2. If you have a weak or failing capacitor, that can contribute to fan motor wear.
  3. Though less likely, sometimes it’s as simple as a limb that falls and obstructs the motor, causing undue wear and tear.

– Tips for Fan Motor Replacement

  1. Make sure you check other electrical components. Maybe it’s the circuit board or capacitor. Get a proper diagnostic and keep a copy of the report.
  2. Replace the fan motor immediately if it fails. Otherwise, you’re wasting a lot of money on an inefficient system and risk creating further costly damages.
  3. If the unit is old and this is not the first costly repair, really consider getting a newer system. Look into variable speed systems like American Standard offers.

For More Information

Check out our video blog AC Maintenance: Fan and Motor

Blower Motor Replacement

A blower motor and fan

The air handler has a blower fan that circulates your home’s air across the evaporator coil. If you’ve ever turned your thermostat fan on, that’s the blower fan motor pushing air through the vents.

– Reasons for Blower Motor Failure

  1. If the motor loses lubricant it can wear prematurely.
  2. If the capacitor is weak and dying, that can cause the blower motor to overwork or just not turn on.
  3. Some systems use a belt to drive the blower. In those cases, the belt could be loose, worn, or broken.
  4. Moisture can corrode the motor windings, and water leaks can ruin a motor.
  5. Other electrical failures can stop a blower motor. Check the circuit board, contactor, and wiring.

– Tips for Blower Motor Replacement

  1. Don’t replace it unless you’ve checked other parts of the system. Get a diagnostic and keep a copy of the report.
  2. If it’s because of moisture or leaks, you should obviously fix the water issues first. Also check to make sure that moisture hasn’t damaged other parts of the system or created mold.
  3. If your system is old and has other issues, you should really consider replacing the system. It may cost more upfront, but a high SEER unit could be cheaper over the long term.

For More Information

Check out our video blog AC Maintenance: Fan and Motor

Related AC Articles

AC Maintenance: Condenser Coil

AC Maintenance: Condenser Coil

A condenser coil is part of the outside AC unit, rejecting heat in the summer and absorbing heat in winter. Here’s how it’s tested on a maintenance check.

AC Maintenance: Thermostat

AC Maintenance: Thermostat

A thermostat senses the temperature in your home, controlling the AC for YOUR desired temperature. Here’s how it’s tested on a maintenance check.

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