AC Troubleshooting: Home Air Conditioner Starts Cold Then Gets Warm

image of a homeowner feeling hot due to air conditioner blowing warm air

Air conditioners should perform consistently. It should cool the house until it reaches your desired temperature and keep it there. If your cooling system is deviating from this expected process, then you may want to investigate the cause. For example, if your home air conditioner starts cold then gets warm as time passes, then it is cause for alarm. This can be frustrating during summer when you are depending on your unit for relief from the heat and humidity.

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AC Troubleshooting: Home Air Conditioner Starts Cold Then Gets Warm

Air conditioners should blow cold air, only stopping when the temperature reaches your preferred thermostat setting. It should not blow warm air all of a sudden. If your system begins with cold air but degrades to warm air, then something isn’t right. In this article, we discuss the common reasons why this cooling system issue happens. Don’t let the situation persist. Call an HVAC technician for help to solve the problem right away.

What Are the Most Common Reasons For An Air Conditioner To Blow Warm Air?

1. Thermostat Settings & Malfunctions

image of hand adjusting thermostat due to air conditioner starting cold and then blowing warm air

The thermostat is the control center of the air conditioning system. It is responsible for sensing the environmental conditions and modulating air conditioner activity to maintain the temperature setting. Assuming that the thermostat is working well, then you might want to check the settings. Perhaps someone changed it while you were not looking or it was programmed to behave that way. It is also possible that the thermostat is malfunctioning due to a low battery charge.

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2. Missing Or Dirty Air Filters

Excessive dirt prevents air from flowing through the filters. This stresses the blower and other components of the air conditioner. It hastens wear and tear, while also reducing system efficiency. Missing filters can be just as destructive since dirt and pollutants can make their way into the cooling system unchecked. Thick dirt around the evaporator coils prevents thermal transfer, also decreasing efficiency. It may even cause the unit to freeze up.

3. Air Filter Maintenance

image of old dirty air conditioner filter from above

Air filters need consistent maintenance. Their effectiveness decreases over time, so you must replace them before they become more of a liability than an asset. This is an easy task that most homeowners can do. The frequency of replacement will depend on the level of use. In a typical family home, it is a good idea to check the filter on a monthly basis. Some homes may need a new filter once every 2 months. If the home has multiple pets, then it may need a monthly HVAC filter replacement. For vacation homes that are seldom occupied, then once every 6 months may be enough.

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4. Low Air Conditioner Refrigerant

The refrigerant is the lifeblood of the air conditioner. It is responsible for transferring heat from inside the house to outside of it. It moves around the system, cooling the home with each cycle. The air conditioner needs a certain level of refrigerant to work well. A leak can lower this amount, decreasing efficiency and causing the cooling system to struggle.

5. Dirty or Damaged HVAC Ductwork

image of an hvac ductwork inspection and repair

In central air conditioning systems, blowers distribute cold air from the source to various rooms in a house using ductwork. If the ducts are damaged, then cold air will leak out. It may no longer reach the farthest rooms. Instead, hot air will come out of the ducts. Aside from this, damaged ductwork can stress the system by forcing it to work harder to achieve the desired performance. This results in wear and tear, and a premature air conditioner replacement.

6. Dirty or Frozen Air Conditioner Evaporator Coils

Evaporator coils capture heat inside the home. If these coils get too dirty, then they will not be able to perform their job correctly. Indoor air won’t be able to heat up the refrigerant flowing inside the coils, and the coils may freeze up as a result. Things can get worse until you intervene. Don’t let this happen by having an HVAC contractor clean the coils on a regular basis.

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7. Air Conditioner Electrical Problems

Lastly, you should watch out for air conditioner electrical issues. If one or more components can’t receive enough power, then a domino effect can occur that results in warm air coming out of the air conditioner blower.


How To Avoid Unnecessary Issues with Your Air Conditioner

1. Replace HVAC Filters Frequently

Ample airflow is vital to proper air conditioner function. Dirty HVAC filters are the biggest obstacle to this, so it makes sense to replace the filters as often as necessary. Don’t let filters sit on your system for longer than 3 months in your family home. You may want to replace it every 2 months just to be safe. Make it monthly if you have pets.

2. Schedule Annual Air Conditioner Maintenance

air conditioner technician performing tune-up

It’s a good idea to conduct intensive cleaning around the house in the spring. It is even better to include annual professional air conditioner maintenance during the season. This will prepare the system for intense operation during summer. The technicians can find emerging issues and deal with them right away. They will also clean and lubricate the cooling system for smoother, more efficient operations. This improves comfort, reduces energy costs, and prolongs your cooling system’s lifespan.

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3. Keep Landscaping at Least 2 Feet Away from the Condenser

Prevent clogs in your outdoor AC unit by being more mindful of dirt and debris. Trim the plants around it to maintain a 2 feet distance between the unit and greenery. Check the top and remove debris whenever necessary. It is common to see dried leaves and twigs around this. Sweep them away or remove them by hand.


What To Do When Your Air Conditioner Is Blowing Warm Air

If your air conditioner is blowing warm air, then you should go through the list above. Investigate the possible causes and pinpoint the exact problem. After that, you can implement the appropriate solution. If the problem persists, then call an HVAC company right away to avoid this problem from escalating into a bigger issue. Early intervention is always cheaper than long-term neglect, as the latter can lead to expensive air conditioner repairs or a full HVAC system replacement.

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Air conditioners are designed to produce cold air. If you feel warm air coming out of your system, then act right away. Troubleshoot to the best of your abilities and seek the help of professional HVAC experts for advanced solutions. Your immediate intervention can save your cooling system from breakdowns and protect your wallet from costly replacements.

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McAllister EnergyMcAllister Energy offers superior heating and cooling services in Camden County, New Jersey. We hire the best-certified technicians who can provide you with excellent HVAC tune-ups, repairs, installations, and replacements. Each of our techs has the knowledge and experience to service your HVAC system correctly.

McAllister Energy guarantees the most competitive heating and cooling service costs in the area. Our maintenance services can improve your comfort, and increase your energy efficiency while reducing your home heating and cooling costs. If you happen to need an HVAC repair or replacement system, we can recommend the best one for your home while staying within your budget. We back all of our work with a guarantee to ensure your satisfaction. To schedule a service appointment, give McAllister Energy a call today. We offer free, in-home estimates.

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