What Does F6 Mean on an Air Conditioner?

Updated: Feb 15, 2024 5:20 PM
what does f6 mean on air conditioner guide

Discovering an error code on any appliance can send chills down the spine, and air conditioners are no exception. However, many owners don’t realize that the best air conditioners come programmed with common error codes to point users toward fixable issues. One such code is F6, which usually indicates a faulty heat sensor. Below, for those wondering what does F6 mean on an air conditioner, we’re about to explain what it means and provide some troubleshooting steps to fix it.

Key Takeaways_

  • The F6 error code commonly indicates that the system’s heat temperature sensor is broken or malfunctioning.
  • Another possible meaning of F6 is that the refrigerant levels are too high.
  • Never attempt to add/remove coolant unless you are an experienced HVAC technician.

Our coverage of AC error codes is extensive, like our article on what E4 means on an air conditioner. You may even consider reading about how to fix an air conditioner fan motor.

insider tip

If you have temperature sensor issues, try running the AC’s defrost mode. Frozen evaporator coils can make the sensor give a false reading.

What F6 Means on an Air Conditioner

The F6 error code is commonly found with window, central, and portable AC units and signifies something is amiss with the unit’s heat sensor. However, it’s critical to keep in mind that each AC unit manufacturer uses a different set of error codes.

For example, although a faulty heat sensor is one of the common causes of error code F6, for some models, this indicates that the refrigerant is overcharged. So, while many codes are the same across AC units, owners should always consult their manuals before trying to fix anything in case of variation.

Fixing Error F6

If you notice that your AC isn’t turning off and continues to cool even though the room is at the right temperature, you likely have a faulty sensor. You can call an expert to fix it or, if you have the skills, hook up a multimeter to run some tests to see if you have a bad connection. You can also check to see if there’s any damaged or faulty wiring.


A faulty heat sensor can increase utility bills because the AC continues the cooling cycle, not knowing when the air has reached its desired temperature.

In the meantime, turn your AC on fan mode so you don’t run up unnecessary energy costs. If you want to know more about this setting, we have an article explaining what does filter reset mean on an air conditioner.

STAT: More than 90% of households in the United States use air conditioning. (source)

On the other hand, if you have an air conditioner in F6 mode and think it’s because of high refrigerant levels, call an experienced HVAC technician immediately. Inadequate coolant levels are dangerous and require professional attention.

Nathan Rizzuti Avatar

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