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Modernization of technology takes us on another level where you have learning thermostats that can learn from our setting of temperature. While accessing the outside temperature, our preferred temperature, as well as inside temperature, they provide us a likely temperature that we like most. It all happens because of Wifi capabilities and AI intelligence. Wifi capability gives us remote control access to control the thermostat from a mobile device or a tablet and pc. No C Wire Smart Thermostats That Work Without Common Wire is the best example of modern technology.

But the story never ends here modern thermostats can integrate with AI-based home assistants that made to take and communicate voice commands and become a bridge to control the whole smart devices from a single place. I like to explore and always pay attention to the technical side and figure out that modern thermostats are equipped with dozens of sensors and need to stay updated and communicate a lot; all of these require the power to run effectively, most common and know source to get power in thermostats is a C-Wire whom we call common wire.

Previously, there were many solutions available that run on batteries, but in the previous decade, the C-wire concept evolved, and the majority of the new thermostat depends on this low voltage wire for power. Until the Birth of smart and learning thermostats, it was nearly impossible to run a thermostat without C-wire or batteries. Every manufacturer was making the thermostats that run on C-wire or using batteries. But wait!

Believe me. It is hard to run a smart thermostat smoothly without C-Wire. Without C-Wire, either it will drop charging or stop working, getting stuck, or you will have fan issues. In every case, the issue is different. To keep the smart thermostats up and working, you need to power them with a C-wire. There are few modern systems where you may not need a C-Wire, but in actual it’s required, or choose an old age thermostat that runs on cells/batteries. 

Modern thermostats are equipped with a backup battery, and they are energy-efficient, and they need only a fraction of power to run compared to old thermostats. These energy-efficient devices can charge their battery and take power from the heat and cool wires so that they can run without C-Wire. Recently I publish a Honeywell wifi thermostat review. Please consider this budget-friendly thermostat.

You might also like our recent blog posts on the Most Commonly Used Alexa Thermostat Commands and Honeywell WiFi Thermostat Reviews available on the separate page.

How to Check if Your Thermostat has a C Wire?

It’s simple; detach your old thermostat and check if the thermostat has a c wire. If there is a terminal with the name C, it means you have a c wire installed system. It is hidden in many cases, especially when it was not required to run your old replaceable battery-powered thermostat; to find it, you need to check your furnace. There is a high chance that a C wire is hiding behind the wall. 

Before buying a new thermostat, it is necessary to check the c wire availability and compatibility of your new selection with your installed HVAC system so you can expect smooth operations and easy installation without incurring any additional cost.

In this article, I list some of the best available thermostats that work without c wire, and all of these solutions modern and can connect to WiFi and AI-based home assistants.

Is Power Adapter An Alternative to C-Wire?

smart thermostat without c wire
HAUTURE C wire adapter 24 Volt Transformer

Yes, it is an alternative to C-wire and a lifeline for thermostats, which has the necessary C-Wire requirement, but your system does not support that. A power adapter plugs into the standard power source and can convert that to a low voltage equivalent to C-Wire.

It usually costs you a few additional dollars but an authentic solution and alternative of C-Wire.

Many manufacturers include power kits in their standard package, so if your old system is not using c wire or not installed, you can power up your thermostat while using that power kit. 

2 Smart Thermostat No C Wire

The solution to C-Wire is very simple and straightforward and instead of looking for a thermostat that works without C-Wire, buy a transformer that will be an alternative to C wire and provide the required power. 

These transformers are very compact and available easily as one is listed above. While some producers include these in the package, if you do not have C-Wire in your existing setup, you can use an adapter to power up your thermostat.

Google Nest 3rd Gen Learning Thermostat

smart thermostat no c wire

Google Nest 3rd Gen Learning Thermostat has improved the original formula and first on the scene as a third-generation thermostat. It is equipped with some excellent and powerful features, a gorgeous display with a multi-color option, and having an overall futuristic look. This is the only thermostat in the market that works without C-Wire and can work without C-Wire with most new heat and cool system.

Usually, it does not need a C-Wire when it gets power through heat and cool wires, but this is not the case with all of the heat and cool systems, and there is no exact compatibility list available, so if a power cycling issue arises, then arrange a common wire through a power adapter.

Its AI-based learning feature makes it different from others that learn from the user setting. While considering outdoor and indoor temperature, it brings the best temperature to the user he likes and most and sets different profiles for individual users. On the other hand, room sensor support makes it a single solution for a complete home.

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Ecobee SmartThermostat with Voice Control

wifi thermostat no c wire

Ecobee Smart Thermostat with Voice Control comes with a power extender kit. So, no need to worry if it will not work without C-Wire. You can use the power extender kit that is included in the package. You will not bear any extra cost; it’s a complete solution with 32 room sensor support and Alexa built-in. Now you can talk with your thermostat, and it will become a central point to control all of your smart devices.

It can integrate with other smart devices in the home. It is equipped with modern processors that are fast and make it responsive as well as efficient. 

It’s packed with many features that are only possible with a thermostat, can make schedules, and compliant with energy-saving schemes. Overall it can save you 23% on heating and cooling bills in a year and will add value to your house because it’s elegant and packed with the features that smart homeowners want nowadays.

Shop now at Amazon

I recommend you to choose an option that you like most and fully compatible with your HVAC. If C-wire is not installed, you can buy a power extender kit or a transformer that will cost you 10 to 15 dollars. Such power adapters come with long wires that make it possible to plug in at any convenient plug or on the other side of the wall where it’s not visible.

I experienced both the power extender kit and the power adapter. I found that; to attach a power extender kit, you need an additional wire in existing wiring or need to free one, which is not useful, to power up your thermostat.

This practice also requires technical knowledge and will take a lot of time. In comparison, the power adapter is easy to use and easy to attach; its an easy to use and does not require any in-depth knowledge of installation.

Why does a Smart Thermostat require a C-Wire?

The reason is straightforward. A smart thermostat needs a constant flow of electricity from the furnace to keep the thermostat running. Smart thermostats equipped with:

  • Wifi
  • Sensors, a dozen of 
  • Display
  • Bluetooth connectivity
  • They also need the power to integrate with smart devices.

All of these require a continuous supply of power to stay connected and keep you updated, and unfortunately, if these smart thermostats run on batteries only, that will last only for an hour or two. Batteries will not provide them enough power to stay responsive and cannot keep them alive for enough periods; thus, the C-Wire is the only long term solution to provide reasonable and uninterrupted power.

Some of the modern models, as listed above, are equipped with circuitry that captures the intermittent power from the red wire that charges the internal battery of the thermostat. It means that it can go completely without C-Wire, but there are only a few furnaces where red wire carries reasonable voltage that can charge the thermostat battery. Even sometimes, when it works, it starts losing power and run on battery only and encounters other problems. But indeed, if you have a modern furnace installed, then it can work smoothly.

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