What Smart Thermostat can I use if my system is not compatible with Nest?

What Smart Thermostat can I use if my system is not compatible with Nest?

You bought a nest thermostat, you went through connecting and troubleshooting the thermostat only to realize that your furnace is not compatible with nest.  

If that is you, you probably started to research other smart thermostat alternatives that probably lead to more confusion and doubt about smart thermostats. You certainly don’t want to go through the hassle of buying another thermostat that may or may not work. You may have even purchased another smart thermostat such as an ecobee or a honeywell thermostat only to realize that these thermostats also did not work with your furnace. If that is you we have the solution for your home that will still allow you to have a connected thermostat that you can control from anywhere in the world. Connected devices are great, they will save you time, money and make your life easier, you shouldn't be punished just because your furnace manufacturer wasn’t thinking about the future.

Our home automation partner network and installation companies have installed hundreds of smart thermostats across the country and over that time we have learned what what works and what doesn’t.

If you're nest did not work even after you installed a common wire and your system was determined to to be incompatible with nest we can explain what the issue is and why just buying one of the competing smart thermostat from ecobee or honeywell won't work.  If you haven’t tried fixing the issue by adding a common wire see this article here about adding a common wire or wire labeled ( C ) you should hire a nest pro to fix the issue. If you already tried the common wire solution and it did not work continue reading below.

The nest and other smart thermostats (ecobee & honeywell) have an internal battery that is charged from your Heating and Cooling System’s low voltage power supply which is the power from the system provided by the red wire behind your thermostat which is either (Rh, Rc, or R). In some furnaces, the power provided from the furnace to the thermostat is too low for the thermostat to recharge its internal batteries. Sometimes you will hear the furnace click when you try and turn it on or sometimes nothing at all happens, your furnace and your smart thermostat just don’t work. The nest will most likely read low power, low battery, a the light on top of the nest will blink red, or it will say there is no power to one of the terminals

There is no modification that can be done to your furnace to fix this issue, the furnace computer and outputs within your furnace were simply not designed to produce enough current for charging.  Making further modifications to your system will either blow a fuse within your furnace or ruin your internal furnace computer.

But fear not there is another solution. You can buy a smart hub such as smartthings with Z-Wave compatibility & Z-Wave Smart thermostat which will allow you to control your home from anywhere you have an internet connection. Trust us you won’t have to worry about having power or charging issues because the solution we recommend runs on 4AA batteries. In our testing the batteries lasted over 2 years before needing replacing. As always we recommend that you use rechargeable batteries because they will save you money in the long run and prevent waste from going to landfill. The reason other smart thermostats (nest, ecobee & honeywell) don’t work is because the require a lot of power for their software, WiFi connection and full color displays and the internal battery can handle the power load without being recharged.  

However a Z-wave thermostat paired with a smart hub uses a minimal amount of power, and can be combined with a smart hub such as Smartthings that will allow you to control your thermostat remotely via your phone, set schedules and turn down the heat when you are away based on your phone's GPS location.   The other advantage of the solution with smartthings is that you will be able to add on other smart devices that you can control via your phone such as lights, locks or even music.

We recommend the following thermostat & smart hub that we have tested and know will work with any low voltage furnace, boiler or heat pump that does not operate on a proprietary system.

Smartthings Smart Home Hub


CT100 Thermostat  Z-Wave Thermostat

The hub takes less than 5 minutes to set up and the thermostat sets up in a few minutes. If you were comfortable setting up the nest thermostat you should have no issues installing the CT100 thermostat and connecting it to the Smartthings Hub. Once the thermostat is connected to the smartthings hub you will be able to control your home from anywhere in the world that you have an internet connection.