Air Conditioner Blowing Hot Air/Not Blowing Hot Air [Solutions]

Some air conditioners produce but heat and cold. So, it may not be an issue if yours blows hot air sometimes. But if you find your air conditioner blowing hot air all the time, you need to find a solution.

Air Conditioner Blowing Hot Inside and Cold Air Outside – Solved

Several faults can cause an air conditioner to blow hot inside and cold outside. When the air filter is dirty, it reduces the airflow. Remove the filter and dust it. If it is the type that you can wash, it is best to wash it. Better still, replace the air filter to improve the airflow.

A dirty filter prevents air from flowing over the evaporator coil, at least not enough. This issue can cause a few malfunctions in the air conditioner, one of which is the evaporator coil freezing. Consequently, the outside condenser unit starts blowing cold air while the inside unit blows hot.

Other possible causes of the problem and their solutions are:

1. Low Refrigerant

When your air conditioner has low refrigerant, you cannot add more on your own. You will need the services of a professional to check for leaks and fix them if necessary before adding refrigerant. Otherwise, it will leak over time if the hole is not patched.

Low refrigerant should not be taken lightly, especially in a home. If you suspect a refrigerant leak, it is crucial to open windows and air the house out. Ensure you have proper cross ventilation and report the issue as quickly as possible. The leak is not dangerous only to the air conditioner but also to your health.

2. Wrong Wiring

Like adding refrigerant to the closed system, you will need the help of a professional to check the wiring. Unless you have the proper training and experience, you may not identify faulty wiring. Get professional to identify faulty or loose wiring and fix it as quickly as possible. It may have happened during the installation or repair service. Another possibility is that the wires may have come loose.

3. Faulty Thermostat

Check the thermostat’s temperature setting and adjust it to the desired point if it is incorrect. Give the air conditioner a couple of hours to run so that you can monitor it. If the unit begins cooling the room and the outside unit blows hot air, you have fixed the problem.

However, if the problem persists, you may have to replace the thermostat. While replacing it, it may help to check the wiring to ensure everything is in order. If the wires are disconnected, reconnect them. Then, fix the thermostat and try the air conditioner again. It should get the unit working again.

The thermostat can cause the air conditioner to blow hot inside and cold outside if it malfunctions. This is especially true if the AC is usually set on Auto. The thermostat can change the functionality and cause the unit to switch from cooling to heating, which causes the outside unit to blow cold air while it grows warm inside.

4. Defective Capacitor

A defective capacitor may be easy to identify because it usually bulges or leaks. So, locate the capacitor and check to see if it is in proper working condition. If it is bulging or leaking, it is time to replace it. 

However, if it does not seem to be defective, you may want to test it with a multimeter to check for continuity. Replace the capacitor if you find no continuity. Replacing the air conditioner capacitor may not be an easy task, so it may help to hire a service agent for the job. And it is crucial to do this quickly because a defective capacitor can cause other problems, including shutting the compressor down.

5. Malfunctioning Compressor

When all else fails, the problem may stem from the compressor. Due to constant use or an internal fault, the compressor can malfunction and cause many problems in the air conditioning unit. If you have checked other parts and they are working, you may want to check the compressor. 

It is not a job recommended for DIYers, but only for professionals. And if the compressor is bad, the technician can determine whether you need a new compressor or AC unit. Replacing a compressor can be expensive.

Car Air Conditioner Blowing Hot Air – What to Do

Take the following steps if your car air conditioner is blowing hot air:

1. Check the Refrigerant Level

Determining the level of the refrigerant may not be a job you can do yourself. That is because it is in a closed system and only a professional can correctly check the level and decide if you need to recharge it. Therefore, hire one to fix the issue.

However, you can use a leak sealer to close the point of the leak. But you must determine what type you need because there are two. One type passes through the system, locates a leak, and solidifies to block it. The other type conditions the seal to swell.

Typically, you do not need to add refrigerant to a closed system because it keeps recycling. But if you find the amount of refrigerant has reduced, it means there is a sealed system leak. Since it is the substance that makes the air cold, your car’s air conditioner will blow only hot air.

2. Check the Condenser

A technician may be able to clean the condenser if it is significantly dirty. But sometimes, the specks of dirt enter the fins and plug them. The technician can remove the dirt in the fins, but if there is damage, the only solution is to replace the condenser. The cost of the repair will depend on the brand and model of the car, but it may expensive.

The location of the condenser makes it easy to get dirty. And when it is dirty, it cannot dissipate heat from the system. Dirt acts as an insulator, trapping heat and preventing an outflow. As a result, the air conditioner overheats and can only blow hot air.

3. Check the Electrical System

Sometimes, the problem stems from loose or faulty wires in the electrical system. While this problem may seem easy, it is not. There are far too many wires in the system to make the job easy. It may mean having to dismantle the entire system before you can find the source. 

That means you cannot do the job yourself; only an experienced technician can correctly fix it. As a result, it is tedious and expensive.

4. Check the Fans

There are a couple of fans that keep the condenser from overheating when it is carrying the hot refrigerant. Locate the fans and see if they are stuck or there are faulty wires. The motors may also be bad and in need of a replacement. Have the technician check the functionality of the fans and replace them if necessary.

5. Check the Compressor

The compressor needs constant use to keep it in shape. If you do not use the car air conditioner often, the compressor may stop working from lack of use. You may want to run the unit every week to keep the compressor and other parts active.

But if the compressor is just not functioning anymore, it is best to replace it. Fortunately, it is a repair that will not cost too much, and when compared to replacing your car, it is more cost-effective.

It is important to note that some cars come with air filters for the air conditioner. Grimy filters will restrict the free flow of air and even if they do not, the only air to come out will be hot air. Clean or replace the air filter for a better-performing air conditioner in your car. The manual of the car will have instructions on how to remove and replace the filter. Otherwise, let a technician replace it.

Regularly servicing your car will prevent issues with the air conditioner. You will not have to make expensive replacements or repairs but will catch errors and faults before they become major problems.

Check out these other articles…

Goodman Air Conditioner Compressor [Problems & Solutions]

Goodman Air Conditioner Freezing Up [How to Fix]

Goodman Air Conditioner Not Cooling [Proven Solution]

What Size Goodman AC Do I Need? [Detailed Answer]

Goodman Air Conditioner Leaking [Proven Solutions]

Goodman Air Conditioner Not Working [How to Fix]

Goodman Air Conditioner Not Turning On [How to Fix]

Air Conditioner Blowing Hot Air in the House – How to Fix

The following are possible fixes if your air conditioner is blowing hot air in your house:

1. Recharge the Unit

Contact an HVAC technician or the manufacturer for immediate service and recharge. When an air conditioner begins to blow only hot air, it may be a pointer to low or no refrigerant. Since refrigerant runs in a closed system and does not usually need refilling, the only cause is a leak. Let the technician check the system, find the leak, and fix it before recharging it.

If you are sure it is a leak in the closed system, you should ensure your home has adequate ventilation running across it. Open doors and windows and consider sitting outside the house while it airs. Though refrigerant is pretty odorless and harmless, inhaling it in large amounts may be detrimental to health.

2. Replace the Thermostat

Check the thermostat to ensure it is not set in heat mode. It may happen accidentally, and it does not hurt to verify. If the thermostat is set correctly, set the air conditioner to Auto instead of Cool and allow it to run for some time.

If the AC continues blowing hot air, you may have a malfunctioning thermostat. Older types may need recalibrating. The user manual may show instructions on how to do it. Otherwise, consider replacing it with a newer type that allows you to program the internal temperature.

3. Change the Air Filter

A dirty and overused air filter will determine how other parts function and whether or not you get cold air. Typically, you should replace the filter every three months or less for the best results. But you can also wash the filter, especially if it has been in use for too long. You will save money on electricity bills while having a cleaner and cooler air in your home.

A dirty air filter can interfere with the thermostat’s functionality and stop the release of cold air. The evaporator coil may freeze due to the dirty filter, leading to hot air in your house. A frozen unit can be messy when it begins to thaw and leak water. Plus, it can cause irreparable damage to the air conditioner.

4. Clean the Condenser

The condenser cannot function if it is blanketed with dirt. Therefore, clean the condenser every month. Experts recommend allowing a professional to do the job because of the condenser fins. They are delicate and may get damaged while you are cleaning. And damaged fins will damage the entire outside unit. However, you can carefully follow instructions to complete the job without any damage.

In addition, clean the area around the condenser unit, up to two feet if possible. Doing this helps prevent more dirt from sticking to the coil so quickly after cleaning it. Ensure the condenser unit sits on a flat and even surface so that it can run efficiently.

Your air conditioner will blow only warm or hot air if the condenser is significantly dirty. This is because dirt covers the coil and prevents the efficient transfer of heat out of the unit. Consequently, the heat restricts cold air from flowing out of the air conditioner.

5. Fix the Fan

Inspect the fan to check the blades, motor, and other moving parts. Lack of lubrication can affect the motor shaft and stop the blades from spinning. You can apply some penetrating oil to the shaft to improve lubrication. Also, ensure the blades are not bent or broken; otherwise, replace them.

Furthermore, check the motor’s bearings. If they are worn, you cannot fix them. The only solution is to replace the motor if the fan should continue running. The same applies if the motor does not have continuity if you test it with a multimeter.

Dirt can affect the functionality of the condenser fan, especially given its location outside the house. The same applies to the blower inside the indoor unit. Dirt can also affect it, though not as frequently as the outdoor fan. Also, age and loose wiring can keep the fans from working. If you are unsure what to do, contact a qualified AC repair agent for assistance.

6. Thaw the Evaporator Coil

Disconnect electric power to the air conditioner and allow some time for the coil to thaw from the ice if it is frozen. After that, the air conditioner may begin to blow cool air if the frozen coil is the problem. But you will need a more permanent fix to the frozen coil problem.

A dirty air filter can lead to a frozen coil, but you may not be able to clean the coil yourself, though you can easily replace the filter. Warm air inside the unit can also cause freezing because of the moisture in the air. When it condenses on the coil, it freezes over time. Servicing the unit will fix the problem.

7. Insulate the Ducts

There may be a leak in the ductwork throughout your house. You may want to have a technician insulate the ducts and install a switch that will turn off the air conditioner when there is such a leak. You may not detect it immediately, but the switch will detect it and turn everything off.

When there is a leak, even if it is just on one spot, the cool air will flow out and not get inside your house. Instead, it will flow into the walls of your house. Over time, you may have moisture issues.

8. Unclog the Drain Tube

A wet/dry vacuum can remove dirt and debris in the tube just as much as a water/vinegar solution will. If you do not have such a vacuum, use the solution to clean the drain tube and repeat it once a month.

The condensate from the air conditioner should flow out of a drain tube into a pan. Over time, dirt can clog the tube, preventing the water from flowing out. As a result, the water backs up into the unit and damages different components. This leads to the unit blowing only hot air. The damage can extend to the walls and furniture in the house if you do not quickly catch and stop it and cause the growth of mold.

Only a handful of people regularly maintain their air conditioning units. All the possible causes of this problem can be averted if you service the unit every month or two. So, get a reliable and qualified technician to check your unit and ensure everything is in proper working order.

Air Conditioner Blowing Hot Air After Power Outage – Quick Fix

A few issues can cause an air conditioner to blow only hot air after a power outage:

1. Circuit Breaker Tripped

If there was a power surge, the breaker can trip and shut power off to protect the air conditioner. The indoor and outdoor units have separate breakers, and while one can trip, the other may stay up even with a power surge.

Therefore, check both circuit breakers, especially the breaker that controls the outdoor unit. If it is tripped, it will explain the hot air in the house. Reset that particular breaker to allow the unit to continue functioning. Fortunately, the fix is not difficult and does not require any expenses unless the breaker panel is damaged.

2. Capacitor Malfunctioned

Go to the condenser unit and open it. You will find the capacitor atop the compressor; it looks like a silver canister. You can immediately tell whether or not the capacitor is faulty if it is bulging or leaking. Replace the capacitor with a compatible one if it is damaged.

But if there is no clear sign of damage, run a continuity test on the capacitor using a multimeter. Finally, replace the capacitor if you find no continuity.

The compressor of the air conditioner needs a capacitor to start and run. If the power outage damages the capacitor, the condenser unit will not work to remove heat. While the unit inside the house continues working, it will blow only hot air because of the non-functional condenser.

3. Compressor Failed

A failed air conditioner compressor keeps the unit from producing cold air. It cannot circulate refrigerant throughout the system to absorb the heat in the air. As a result, the unit will produce air with all the heat.

Get a qualified HVAC technician to check the compressor and let you know if the power outage has damaged it. You can decide if a new compressor or air conditioner is more cost-effective.

Car Air Conditioner Blowing Hot Air on One Side – Quick Fix

The actuator of the temperature blend door may be damaged. It may also be that the temperature setting is wrong. Try adjusting the setting to allow both sides to blow cold air or hot air when needed. Ensure the temperature degree is at the desired point.

If that does not fix the problem, check the control module of the air conditioner; it may need to be reset. The battery of the car can interrupt the function of the module if you ever disconnect it. The module may no longer be able to conduct a self-test in order to find the location of the actuator of the blend door. You need to recalibrate the module in such a situation to reset it.

Disconnect the battery’s negative terminal and leave it for about five minutes. After the time, rev the ignition but do not touch the controls of the air conditioner. That may reset the control module.

But if the module is not the source of the problem, you may want to check the actuator as a last resort. Let a technician determine whether or not the actuator is faulty and if it needs a replacement.

Air Conditioner Blowing Hot Air, Fan Not Spinning – Solved

A bad fan motor, broken blades, defective relay board, thermostat, thermistor, capacitor, selector switch, or main control board can cause the air conditioner fan to stop running. This article describes each problem and possible ways to solve them.

Air Conditioner Blowing Hot Air, Outside Unit Not Running – Quick Fix

Ensure the thermostat is on and is working. Next, check its setting to be sure it is set to cool. You or someone else may have accidentally changed the setting. The temperature should be set about five degrees below the current room temperature. 

A technician should inspect the batteries and check the wires to ensure they are have not been chewed by a rodent. You may have to replace the thermostat if it is no longer working.

Another possible cause of the problem is dirt. The outside condenser unit may be clogged with all types of dirt. So, it is crucial to hire a technician to check and clean the unit if necessary. Clean the unit as often as once a month. Also, clean the area around the unit and ensure you always keep it clean.

Try resetting the unit by turning the breaker that controls the outside unit off or turning off the thermostat. Turn it back on after a minute and wait a few minutes for the condenser to kick into action. If that does not happen, contact a technician to find the more complex source of the problem.


An air conditioner blowing hot air is a serious problem that needs immediate solutions. Fortunately, there are quick and easy ways to fix the problem as we have explained in this article. Keep an eye on your home or car air conditioner as much as possible, and have it serviced as regularly as you can. Always use an experienced HVAC technician for the job.

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