If you find the air conditioner blowing warm or hot air in your Grand Rapids area home this summer, your frustration levels are probably rising alongside the heat in your living areas! Hot air flowing from an air conditioning unit is a common problem which may be solvable through some DIY troubleshooting.

In our most recent blog, the technicians at A-1 Mechanical discuss the causes of this troublesome AC problem, what to do to fix it, and when to call in our Michigan air conditioner repair pros for solutions.

Causes Behind an Air Conditioner Blowing Warm Air

If you have an air conditioner blowing hot air during the summer months, here are the most common causes and what you can do to correct them or when to call for AC repairs.

Incorrect Thermostat Settings

In bigger households, it’s easy for thermostat settings to be adjusted without the knowledge of other family members. If someone accidentally turns the thermostat to HEAT mode, it won’t be your air conditioning system generating hot air – it’s actually your furnace running, heating the home! 

Another issue with thermostat settings that can send hot air into the home is a fan set to ON mode instead of AUTO. When the AUTO setting is selected, your HVAC system’s fan only runs with a cooling cycle to circulate chilled air into living spaces across the house. When ON mode is selected, the fan will run all the time. In between cooling cycles, the fan pushes warm air through the vents, because air is not actively being cooled.

Whenever you have an AC system that’s blowing hot air, it’s wise to check the thermostat settings first.

  • Make sure the thermostat switch is set to COOL mode, not HEAT or HEAT/COOL.
  • Check the fan settings switch and make sure it is set to AUTO mode, and not ON.

Dirty Air Filter

A dirty air filter can cause your air conditioner to blow hot air out of the vents. When the filter becomes clogged with contaminants, it creates a blockage, and your cooling system must work harder to circulate air through this obstacle. Your air conditioning system may not be able to generate enough airflow, leaving the air feeling warm as it exits your vents. All the while, your air conditioner will be wasting electricity as it attempts to compensate for the restrictive filter.

Check your HVAC filter and replace it as needed. It’s wise to check air filters once per month in the summer, as replacement may be needed more often during this season of increased system usage.

  1. Remove the old filter from the filter cabinet.
  2. Look at the filter’s surface – if it is completely caked in greyish material, it needs to be replaced. If you are unsure, hold the filter up to a light and see if you notice any light shining through. If no light passes through the filter, replace it.
  3. Insert a new filter into the filter cabinet. Make sure to follow the airflow arrows on its frame which tell you the proper direction for filter installation. Make sure the filter is the correct size and fits snugly into the cabinet.

Dirty AC Coils

Your central air conditioner or heat pump has two sets of coils – the indoor evaporator coil, and the outdoor condenser coil. If either of these coils are dirty, the system struggles to complete heat transfer, which can result in your AC blowing warm air. A dirty evaporator coil prevents it from absorbing heat within the indoor air; dirt on the condenser coil, meanwhile, prevents the system from efficiently releasing heat outdoors.

Coil cleaning is a job best left to the professionals. If you suspect your coils may be dirty, you can check by disconnecting power to the system and opening the access door to your furnace or air handler indoors to check the condition of the evaporator coils, or look inside the outdoor condenser unit or heat pump unit to check the condenser coils. If either are covered in dirt or grime, call your HVAC company to clean the coils.

Contact A-1 Mechanical for Relief from Hot Air

If you have an AC blowing warm air and the above troubleshooting steps don’t work, call A-1 Mechanical to perform air conditioner repairs at your home. Our technicians perform diagnostics to find out why you have an air conditioner blowing hot air so the correct repairs can be made to solve the problem once and for all.

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