Mitsubishi Thermostat won’t Go Below 67 [Explained!]

Are you having trouble with your Mitsubishi thermostat refusing to go below 67 degrees? If so, you’re not alone. 

Many homeowners have experienced this common issue and are looking for a fix. Still, if you want a temperature below 67 degrees, it can be a difficult task in this situation.

So, what do you do when the Mitsubishi thermostat won’t go below 67 degrees?

Firstly, check the temperature settings on your Mitsubishi thermostat and make sure the mode is set to ‘cooling’. Secondly, clear the restricted airflow by opening up vents and registers. Thirdly, check the thermostat sensor to see if it’s working, if not, replace it.

That’s not the entire information you need to fix this issue. Read the full article to properly diagnose and fix this problem.

Why Won’t Mitsubishi Thermostat Go Below 67 Degrees: 3 Reasons & Solutions

There could be a few reasons why your Mitsubishi thermostat is not going below 67 degrees. Here are some possible explanations-

Reason 1: Incorrect Temperature Settings

Incorrect Temperature Settings

If your temperature settings are wrong, the Mitsubishi thermostat will have difficulties going lower than 67 degrees.


First, check that the temperature setting is set correctly. Make sure the thermostat is not in “heat” mode and is set to “cool” mode. Also, check the temperature setting to ensure it is below 67 degrees.

If your Mitsubishi thermostat is in a 2-wire setup, it can only control heating and cooling individually. If you want more settings, consider installing the 2-wire thermostat in a 4-wire setup.

Additionally, if you’re going to set the temperature below 67 degrees in ‘heating’ mode, you can do it. Use Mitsubishi’s Kumo Cloud app to control the thermostat and alter the temperature. Your thermostat has to have wifi sensors in order for it to work though.

Reason 2: Restricted Airflow

Whenever you’re using an air conditioner in a room, the room needs to have proper airflow. If there are any blockages or restrictions, it could prevent the room from cooling down properly.


Check the airflow in the room. Make sure all vents and registers are open and free of obstructions. Additionally, make sure no other equipment is hampering the functionality of the air conditioner. You can use an air purifier to increase airflow inside your room.

Reason 3: Sensor Issues 

When the temperature sensor is faulty, it can quite easily cause this issue. The thermostat may not be registering the correct temperature, which could prevent it from going below 67 degrees.

Bad sensors can cause many other problems like the thermostat intermittently losing power, blown fuses, etc. 

Try keeping your air conditioner peripherals (sensors, air filters, etc) clean to boost efficiency, it’s fairly easy! For instance, you can simply use a screwdriver and a vacuum cleaner to clean the air filters of your AC.


In such cases, replacing the thermostat sensor will be the best decision. Call an HVAC professional and get your thermostat sensor replaced. You can also use thermostats with room sensors for your convenience.

Reason 4: Low Temperature Outside

Low Temperature Outside

If the temperature outside is too low, the Mitsubishi thermostat won’t go below 67 degrees. Generally, air conditioners are designed to cool your home 15-20 degrees lower than the outside temperature.

If the outside temperature is not 85 or more degrees, it won’t be possible to get the thermostat below 67 degrees. 

Another feasible solution is changing the thermostat. For example, switching to a thermostat from a different manufacturer might let you go below 67 degrees. Still, you should consult the idea with customer support. Heads up, it will get expensive!

Furthermore, if you have a Mitsubishi remote with the smart set option, you can go below 67 degrees. It’s also known as the ‘vacation mode’.

You’ll find this option behind the slider of the remote (a small diamond symbol, at the bottom middle). You can ping your AC at 50 degrees with this option!

Should You Set Your Thermostat Below 67?

Here are some consequences of setting your thermostat below 67:

Due to this, the air conditioner’s coils get blocked and it cannot effectively cool anymore. Furthermore, the components inside your AC might get damaged.

  • Healthwise, it could be fatal. 67 degrees is too cold for an average person. Here is some temperature benchmarks you should look into:
Temperature range (F)ConditionRisks
70 – 75Very WarmSlightly Unsafe
65 – 70ComfortableNo Risks
55 – 65Fairly ColdSlightly Unsafe
45 – 55ColdUnsafe
Under 45Too ColdVery Risky
  • It’s not permissible to have this much of a low temperature, legally. Although this does not apply to all states; you should check your state’s laws.
  • Your bills might be really high. The lower the temperature for a thermostat, the longer it has to operate to achieve that temperature. So your air conditioner will function for longer. 

How to Lower the Minimum Set Point on the Mitsubishi Thermostat

If you want to set lower temperatures on your Mitsubishi thermostat, you need to change the settings. Follow the steps below to change the minimum and maximum set points-

  • First, turn on the Mitsubishi thermostat.
  • Then, find the ‘Menu’ button and press and hold it for 5 seconds. It will bring the ‘Installer’ menu to the screen.
  • Next, use the arrow buttons to scroll down to line 181. In that line, you’ll find the minimum set point for cooling.

    Set the value to your preferences. The lowest you can go is 50 degrees.
  • Finally, after altering the settings, scroll up and press ‘Done’. This will change the minimum cooling settings.

Frequently Asked Questions (FAQs):

How do I reset my AC thermostat?

To reset your AC thermostat, first, turn off your AC from your thermostat. Then, find the circuit breaker box of your home. From there, reset the circuit breaker for the AC unit. Next, wait approximately 30 seconds. Finally, turn your AC thermostat back on.

Can I use dry mode all day?

No, it is not recommended to use dry mode all day. Using dry mode for more than 1-2 hours may overdry the air. Activating dry mode in your AC won’t remove 100% of the moisture present in the air. The dry mode can only lower the humidity level of the environment, to a healthy level. 

What is the normal temperature for cooling?

The normal temperature for cooling is 78° Fahrenheit. At this temperature, the AC unit maximizes comfort, energy saving, and steady cooling. Still, this is an approximate value for the normal temperature outside. If the temperature outside changes, so will this one!

The Final Words

This is the final stretch of this article. Hopefully, now you know the reason why the Mitsubishi thermostat won’t go below 67 degrees.  
It will be the best decision to call an HVAC expert if you’re confused with anything. Tampering with the HVAC settings too frequently might damage it.

Best of luck.

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