This article explains in detail how to reset a Lennox thermostat.

Are you finding it difficult to explain or understand why your thermostat isn’t maintaining a consistent temperature in your home? Don’t stress it. There are many explainable reasons for your thermostat behaving like that. 

So before you call in a technician to come and check it out, there are several measures that you can try to see whether the problem revolving around your Lennox thermostat clears out. So how can you do that? By doing a quick reset. 

Just like tablets, laptops, and smartphones, your digital Lennox thermostat could use a reset as well. Why do this? This is because your Lennox could be having common issues like inconsistent temperatures and poor airflow that do not always require repair or even replacement. Most of the time it all takes a quick reset and everything goes back to the way they were without spending a dime or even putting extra effort into figuring things out. 

It is only when your Lennox thermostat doesn’t work after a quick reboot that you should call in assistance. But how can you reset your thermostat? Read on and you will find out more in that regard. 

How do I Reset My Lennox Thermostat?

As said earlier, there could be several reasons as to why your Lennox thermostat is not working properly. And sometimes it could be hard to determine the cause of it. But resetting it has proven to be effective over the years. That is why we are providing you with some of the steps that will guide you to reset your thermostat and help it work again. 

  • Switch off the Lennox thermostat, then head to the circuit breaker box.
  • Find the switch that controls your HVAC system and switch it off. 
  • Wait for about 30 seconds before flipping it back on. 
  • Return to your Lennox thermostat and turn it on as well. 
  • The thermostat will reboot itself. The screen will go blank for 3 seconds tops before the home screen appears. 
  • Then adjust your home’s heating and cooling setting to your preferences. 

When that doesn’t pan out as you hoped for. If your thermostat doesn’t get back to working as it should, you can reset your furnace working motor as well. And how do can you do that? 

  • Turn off the power of your furnace at the circuit breaker. 
  • Lift up the blower compartment lid, to access the wheel and motor of the blower. 
  • Search for a red or yellow button on the side of the motor.
  • Then press it down for the furnace to restart. 

If this doesn’t seem to solve anything then you can call in your reliable technician.

Lennox 15Z69 iComfort M30 Universal Smart Programmable Thermostat, 4.3" LCD Color Display, Geo-Fencing, Remote Access, Wi-Fi and Alexa Enabled

How Do You Know that it is Time to Reset Your Thermostat? 

You will come to know that a reset is needed when you notice that your thermostat isn’t regulating temperature as it normally does. So just follow the step mentioned above and remember if that doesn’t work you can call in your technician. 

Why is my Lennox thermostat, Blank?

If you switch on your Lennox thermostat and appears blank, the most probable cause could be that its battery could have a run-out. That means you have to check whether your batteries need to be changed. If your Lennox uses the home electrical system then check your circuit breaker. You might find that a reset is required. 

How Do I Clear Lennox Error?

You can just unplug it from the switch, shut down your home’s main switch then wait for about 10-15 minutes before switching it back on.

Why is my Lennox Thermostat not Working? 

If you find that your thermostat isn’t working, it’s probably because the batteries are out of juice.  You can check if that is true by replacing new batteries before switching them back on.  If it still becomes an issue then you can call in a repairman to check the problem. 

How Can I Adjust a Lennox Thermostat?

  1. Settings Time and Date

This is how you can set your time and date on your Lennox Thermostat

  • Use the arrows on your thermostat to proceed to settings their time and date
  • When the time and date appear on the screen, then enter the correct time and date
  • You can click on the up or down arrows to find the right date and time. 
  • Press ok to save the changes
  • When you have completed the whole process press done. 
  1. Temperature

The temperature changes can be made from the homes screen on your thermostat or your phone app.  This can be changed by doing the following:

  • Choose the option, ‘temperature’ from the set of options that appear on the screen 
  • Press the arrow buttons to reach your desired temperature. 
  • Then press ok to finalize your choice.
  1. Humidity

To adjust the humidity:

  • Select the indoor humidity tab.
  • Press ‘select’ to tell the system which humidity you want
  • Then press ‘change’ to what you want to adjust to. 

Does A Lennox Icomfort Thermostat have batteries? 

Yes, it does. And you can check if that’s true by pulling out the wall plate behind the thermostat itself if it stops working and replacing the batteries with a new one. Then close the compartment. 

How do I Connect my Lennox Thermostat to my Wireless Network?

  • Go to Settings on your home screen.
  • Then Networks. 
  • Select your network when it appears on the screen. 
  • Then press ‘connect’ to finish the process. 

How do you know it’s time to Replace Your Lennox Thermostat?

Your thermostat is the key to making you comfortable in your own home, and if you are uncomfortable because it’s too hot or too cold in your home then your thermostat has to change. But how can you know this?

  • if your thermostat gives you a faulty reading
  • if your thermostat doesn’t respond to setting changes
  • If your thermostat’s temperature constantly changes without your say in it. 
  • If your HVAC system is short cycling
  • If your thermostat is analog.
  • If your thermostat isn’t programmable
  • If your bills become too high. 
  • If your HVAC system turns on and off without reason. 

Why is my Lennox Furnace Blinking Red?

If you notice that your thermostat is blinking red then this could mean that it has a low flame signal and that it could mean that the flame rod in your furnace needs to be cleaned. And here are some of the other lights that might appear on your Lennox with their meaning:

  • Unlit light- this indicates that the thermostat is not on.
  • Steady yellow light- this shows that the thermostat is booting up or the process is already completed and it is up and running.
  • Flashing yellow- indicates that the WIFI configuration is in progress. 
  • Flashing red- indicates that there is a problem with the furnace. 


Lennox thermostats are the most efficient thermostats a homeowner can own as they are efficient and provide the right temperatures for your home. But sometimes, just like other devices, it gets a hiccup. 

It is quite common for your thermostat to sometimes stop producing a consistent temperature in your own home. And that doesn’t mean that your thermostat is broken but only that it needs a reset to let it go back the way it was. And it is only when the reset doesn’t work on your Lennox thermostat do you need a repairman to look at it. 


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