What Is the Difference Between Honeywell T9 and T10?

honeywell t9 t10honeywell t9 t10

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If you are searching for new thermostats for your home, you have probably come across Honeywell smart thermostats; they are one of the most well-known brands in the business with several options, such as the Honeywell T9 and T10. But what’s the difference between these two devices?

The Honeywell T9 and T10 thermostats have many of the same features, but the main difference is that the T10 has a dual fuel mode. The T10 can let you have two sources for heating and cooling, which may be required for your home depending on the wiring and pumps that you have.

You might still be wondering what dual fuel mode is and if you might need it. Don’t worry; we go over all the details in this article. We will also discuss some additional differences between the two models.

Honeywell T9 vs. T10 Thermostats

The Honeywell T9 and T10 thermostats have many of the same features but also have some distinct qualities. The one you should buy depends on your personal preferences and the qualities you want in a thermostat.

Check out the chart below for a detailed comparison of the thermostats:

VoltageLow VoltageMillivolt, Low Voltage
FeaturesRemote Programming, ProgrammableRemote Programming, Programmable
ScreenTouchscreen, DigitalDigital
Assistant SupportAmazon Alexa, Siri, Google AssistantAmazon Alexa, Google Assistant
Wiring/InstallationC-wire, Wire-sensing, DIYMore Wires, Professional Installation
Price$150+ depending on sensors$180+ depending on sensors
ControlsTemperatureTemperature, humidity, ventilation

Dual Fuel Mode

The largest difference comes with the fuel mode as mentioned above and the extra controls that the T10 has. The dual-fuel mode on the T10 means that it can control your heat pump as well as the gas furnace. If your heat pump stops working or pauses, the gas furnace will automatically take over and control the thermostat. If you don’t have a gas furnace or aren’t worried about the dual fuel mode, then owning theT9 could be a better choice and save you money. 

If you aren’t sure if you need dual fuel more, consider calling a professional to come to look at your system and pump. This will save you money and time when looking for the perfect thermostat.

Controlling Humidity and Ventilation

If you want to control your home’s humidity and ventilation, you won’t be able to use the T9. The T9 can measure your humidity and tell you if your levels are unhealthy, but it won’t be able to change the moisture level as the T10 can.


Another important point to think about is the installation. Due to its more advanced control mechanisms, the T10 has many more wires than the T9. The T10 is hard to install as a DIY project. The 5-year warranty is also only valid if you have proof of a professional installation.

Try to install the T10 by yourself can be difficult and void your warranty. So, make sure you have an HVAC worker help you with the installation. 

Voice Assistant Compatibility

The T9 can also be controlled by Siri, while the T10 cannot. If you solely use Siri as your home assistant, the T9 might be a better choice.

Similarities Between the Honeywell T9 and T10 Thermostat

Both the T9 and T10 thermostats by Honeywell sense the temperature and humidity in your home. The sensors can also read the temperatures of multiple rooms in your home and then average them together.

The average temperature is the one that’s displayed on your home’s main thermostat. The more sensors you have, the more accurate your temperature display will be. However, the thermostat and sensors alone cannot control the temperatures separately. They can only tell you the conditions of the room.

Some additional important similarities are:

  • Chic flat rectangular design
  • Measure temperature and humidity
  • Comes with one sensor
  • Both can be synced with up to 20 sensors
  • Large screens
  • Lightweight design
  • Both offer voice control
  • Both work with the Honeywell Home App

The reviews are also about the same. The T9 has an average of 4.1 stars on Amazon, while the T10 has an average of 4.1 stars. The price is also not too much different, with the T10 being about $30 more on average. The starting package comes with one sensor for both the T9 and the T10. The more sensors you buy, the higher the price will be.

Overall, the temperatures have many similarities because they are both from the T-series. If you want a basic thermostat and don’t need dual fuel mode, save some money and get the T9.

In Summary

The most significant difference between the Honeywell T9 and T10 thermostats is that the T10 can control humidity and ventilation. If you have a smart home ventilation system and want to make your home more efficient, definitely get the T10. The installation process is also different for each one; the T10 will need a professional, and the T9 is DIY. 

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