Why is My AC Blowing Hot Air in My Home?

Setting the AC to cool the room only to notice rising temperatures could leave you wondering, ‘why is my AC blowing hot air?’ The hot air can make the rooms uncomfortable, especially during summer.

A major reason your AC is blowing hot air is low refrigerant. When the refrigerant leaks, the little amount left can’t effectively cool the room. Before scheduling repairs, check if the air filters and condenser coils are clean and fans are working correctly.

If you cannot detect the problem, hire an experienced HVAC technician to inspect your system. They will inspect other delicate mechanical parts and advice on any repairs or replacements needed.

Why Is My AC Blowing Hot Air In My House?

Homeowners can set their AC to blow cold or hot air in the rooms, depending on the season and temperatures. For example, during summer, temperatures are high, and to cool the room, you must set the system to blow cold air in the room.

However, sometimes you’ll notice that the air is still warm. Given the cost of repairs or replacing the entire system, having an ineffective machine can be stressful. However, warm air from the HVAC is a problem many homeowners experiences.

When it happens, you first need to find out the reason and know the solution. Therefore, we will mention why AC blows hot air and the best solution.

     1. Low Refrigerant

Low refrigerant is one of the primary reasons your AC is blowing hot air in the rooms. The refrigerant ensures the proper performance of the unit by absorbing heat and humidity. With little refrigerant, excess heat in a room won’t get absorbed efficiently.

Leaks can cause low refrigerants. When the refrigerant is low, there will be less cooling and the room’s high humidity. Therefore, once you notice the low levels of the refrigerant, you should first find the leaks and repair the holes.

Finding refrigerant leaks is hard and time-consuming, so most homeowners prefer replacing them. But, first, hire an HVAC professional to check and see if there are leaks. They will do the replacement and leave your unit running.

     2. Poor Thermostat Setting

Your system could be working correctly, but if you got the thermostat settings incorrectly, you would have hot air blowing into the rooms. This happens mostly to manual thermostats with wrong calibrations.

Check your thermostat settings and ensure they are the right ones for summer. If you have a faulty thermostat, you will need a replacement. You should also change the settings from “on” mode to “auto.”

While on your thermostat, check if you left it on heat mode. You can instead get a programmable thermostat that keeps your home’s temperatures consistent. You won’t need to keep changing the settings.

     3. Dirty Filters

When lastly did you check your air conditioner’s filters? Dirty air filters make your system ineffective, which could be why there is warm air. Also, during the cooling process, warm air passes through the filters before it is cooled.

The filters clog when dirty and dusty, and the warm air cannot pass through. This causes the evaporator coils to freeze, warming the house’s air. So, homeowners should check the air filters during HVAC maintenance to ensure they are clean.

Besides blocking air passage, dirty filters make it harder for the HVAC to operate, causing a breakdown of some mechanical parts. In addition, it could lead to expensive repairs or system replacement.

     4. Faulty Outdoor Unit

While still researching ‘why is my house ac blowing hot air,’ another reason you will find is a faulty outdoor unit. This is because the two major parts of an air conditioning system are the indoor and outdoor units.

The outdoor unit cools the air down, and the indoor unit blows it into the rooms. Therefore, if there is hot air in the house, it could be because the outdoor unit is not working well.

Check if there is an adequate power supply to the unit. Lack of power could be due to a tripped circuit breaker or a blown fuse. If these are the causes, you will need a professional to deal with the problem.

     5. Clogged Drains

Homeowners are reluctant to check the condition of their drains, but these are essential parts of the HVAC. When the AC collects moisture from the rooms, it exits through the drain line.

If dust, dirt, and debris clog the drains, the water won’t exit the system. It could return to the unit causing greater damage. If left unrepaired, clogged drains leak, causing other problems like mold growth and a musty smell.

If your drain pipes are clogged, you can easily and quickly fix them. Wear protective gloves and try to pull the dirt causing the blockage. If it is hard to clean, pour a vinegar and water mixture and let the dirt dissolve. You can then wash the drain pipe with clean water.

     6. Leaking Ducts

Leaking ducts could be another reason your home ac is blowing hot air. Some leaks are hard to notice because they are caused by small animals like rodents. Others could be due to poor handling of the system during installation.

Ducts are installed through the walls to the ceilings and carry cool air throughout the home. However, the cooled air might not reach the rooms if there are holes. As a result, the warm air will remain in the rooms, making them hot.

If you suspect leaking ducts, get an overflow switch. When there is a duct leak, the overflow switch will shut down the system to prevent any damage. You can then call an HVAC specialist to check your system.

     7. Failing Fans

Another answer to ‘why is my home ac blowing hot air could be ineffective fans. Fans become faulty due to inefficient motor, lack of lubrication, and old and worn belts.

Check if there is dirt and debris around the fan area because it could prevent it from propelling properly. This happens mainly in the outdoor unit exposed to leaves, branches, and debris.

An ineffective fan causes poor airflow, reducing the effectiveness of the ac in cooling the air. It will therefore cause hot air in the rooms. Unfortunately, most homeowners overlook fan problems, but they cause compressor failure.

Final Words

Why is my ac blowing hot air? This is a common question homeowners will ask HVAC experts when there is less air cooling by the system. Clogged drain pipes, low levels of refrigerants, and faulty fans are some reasons your rooms are hot despite having an HVAC. Hire an AC expert to deal with these problems professionally.

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