Why Does Your Air Conditioner Fan Keep Running When Turned Off?


Have you noticed your air conditioner’s fan buzzing even after switching it off?

Have you been left puzzled and asked yourself why this could be happening?

Your air conditioner fan might still run when turned off; we’ll provide insight into why and explain why it’s necessary to call a professional HVAC technician to rectify this problem.

By understanding the advantages of professional intervention, you can extend the lifespan of your air conditioning system and enjoy a more comfortable and cost-efficient home environment.

After reading this article, be sure to check out Hurliman Heating for all your HVAC needs.

6 reasons your air conditioner fan keeps running when turned off

Imagine a hot summer day, and you’ve just turned off your air conditioner.

However, you notice that your AC compressor turns off but the fan keeps running. This continuous operation not only increases your energy costs but also strains your HVAC system. 

This situation could be indicative of several underlying issues. 

Here we delve into 6 reasons why your AC fan keeps running after the compressor shuts off, offering you insights into what might be going wrong.

  1. Faulty thermostat settings

Putting the thermostat to ON instead of AUTO could cause your fan to run continuously even when cooling is not active, leading to endlessly running fan blades. Make sure your thermostat settings are correctly set and that the unit isn’t faulty if this seems like the cause.

Checking this first could save time troubleshooting any future problems with fans running non-stop and unnecessary cooling cycles.

  1. A malfunctioning fan relay

Fan relays control when and how frequently fans turn on and off, so if it becomes defective or stuck, your fan might continue running even after turning off your system. If this were to occur, you would notice continuous fan operation without pauses, signaling an issue with its performance and possibly signaling a malfunction of the fan relay.

  1. Issues with the control board

The control board governs the operations of different components of the air conditioning system. A fault in this board could lead to the fan running non-stop. When the control board malfunctions, it might send incorrect signals, causing the fan to run endlessly.

  1. Faulty fan limit switch

Fan limit switches work by turning on and off based on the temperature inside your furnace, but a faulty switch could cause it to run continuously instead of on and off when temperatures are cool in your house. If this is happening to you, this could indicate a bad fan limit switch in play.

  1. Excessive heat

If your home is particularly hot, your air conditioning system might be working overtime to try to cool it down. This can result in the fan running continuously. Under extreme heat conditions, HVAC systems must work harder to keep indoor temperatures comfortable; this often necessitates continuous fan operation.

  1. Air conditioner unit size

As another possibility, your air conditioning system could be too small to adequately cool the space it is designed for, putting additional strain on its fan. If your AC fan keeps running continuously during heat waves or sweltering weather, this might be why. Pick an adequately-sized AC unit for your home to prevent this issue from arising in future years.

Why regular maintenance is the key to keeping cool

Routine HVAC maintenance is pivotal for keeping your air conditioner in optimal working condition. Regularly scheduled maintenance can help identify potential issues early on, preventing minor problems from escalating into major repairs. 

For instance, a malfunctioning fan relay or control board can be spotted and rectified in a timely manner, preventing the fan from running continuously and placing unnecessary strain on the system. 

Regular checks of the fan limit switch can also ensure it’s working correctly, further preventing unneeded operation of the fan.

In the case of excessive heat, maintenance checks can confirm whether the system is appropriately sized for the space it’s cooling. An undersized system will work overtime to maintain a comfortable temperature, leading to frequent fan operation and potential degradation over time. 

Regular maintenance ensures that your system is functioning at its most efficient, helping maintain a comfortable indoor temperature, even during a heat wave. 

In essence, routine maintenance is an essential practice for the long-term, efficient functioning of your air conditioning system.

Why does your air conditioner fan keep running when turned off? – conclusion

In conclusion, if your air conditioner is off but the fan keeps running, it could be indicative of a malfunction within the system. 

Various factors can lead to the continuous operation of your air conditioner fan, including: 

  • Malfunctioning components, such as the fan relay and control board
  • An incorrectly set fan limit switch 
  • Excessive heat
  • Unit size

Regular maintenance is crucial in identifying these issues early, ensuring the system’s functionality, and preventing unnecessary strain from ongoing fan operation. You can enjoy a long-lasting, efficiently running air conditioning system by understanding these potential issues and ensuring timely maintenance. 

Contact the professionals at Hurliman Heating & Air Conditioning today. We’re here to ensure you get the most out of your system, and we’re just a click away.

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