I Tested And Reviewed 10 Best Smart Thermostat Without C Wire (2023)

I recently purchased the Neat Thermostat Adaptor and I must say, it was exactly what I needed. The installation process was a breeze and it worked perfectly right from the start. My house has old heating systems, but even though they are analog, they still run at 24V. The Neat Thermostat Adaptor made it easy to connect my thermostat without the need for rewiring or extra transformers.

One of the key features of this adaptor is its ability to find the common neutral, also known as the C terminal. By using a multi meter and referring to the system's wiring diagram, I was able to easily connect the adaptor without any complications. I even helped my neighbor with their Taco zone controller, which did not have a defined C terminal. We simply added a jumper to the neutral line from the transformer using a volt meter.

I want to address some misconceptions I've seen in other reviews. Contrary to what some people have said, you do not necessarily need a C-Wire for this adaptor to work. What you need to ensure is that your HVAC or Furnace has a C terminal on the circuit board. In my case, I have a 1987 gas Furnace with only a Red/White wire, but the circuit board had a C/G/Y/W/R terminal. I connected my R/W wires to the connectors and hooked up the R/W and C to the board, and it worked like a charm.

I would also like to mention that it is important to check for any "dumb" issues before assuming that the adaptor is not working. Double check your wiring, circuit breakers, and make sure you have closed the furnace service panel correctly. In my case, I discovered that my furnace was not engaging because I had not closed the panel correctly. Once I fixed that, everything worked perfectly.

After reading mixed reviews, I was initially skeptical, but I decided to give the Neat Thermostat Adaptor a try. I was worried that my furnace system might not run on 24V, but luckily, the voltage was printed on the circuit board in my furnace. This made the installation process even easier.

Since installing the Neat Thermostat Adaptor, I no longer have to deal with low battery issues or disconnections from WiFi. My Nest thermostat now works reliably, and I can easily access it from my phone app. If you've been frustrated with low battery problems with your Nest device, I highly recommend giving the Neat Thermostat Adaptor a try. It solved all my issues and I couldn't be happier with the results.

The Sensi Lite thermostat is a straightforward yet highly functional smart thermostat that ticks all the boxes for a user's needs. While there are more expensive options available on the market, none can match the heating and cooling capabilities of this thermostat.

One of the standout features of the Sensi Lite is its clean and user-friendly app interface. It allows you to set multiple heat and cool scenarios and activate them as needed. Additionally, the "Early Start" feature is a great addition, as it starts heating or cooling early to achieve your desired temperature at the specified time.

A major advantage of this thermostat is that it works perfectly even without a C-Wire. This is a relief for those who don't have a C-Wire and don't want to go through the hassle of installing one. Whether you have a C-Wire or not, this thermostat will do an excellent job of keeping your home comfortable without any C-Wire nightmares.

Unlike some more expensive smart thermostats, the Sensi Lite has a rock-solid online connection. It stays consistently connected to Wi-Fi, ensuring that you can always check the temperature or make adjustments even when you're away from home. This reliability is a significant plus for those who have experienced frustratingly unreliable connections with other thermostats.

Having personally recommended the Sensi Lite to family members, I can confidently say that if you want a thermostat that reliably maintains your desired temperature range without any worries about malfunctions, this is the one for you. In comparison to other smart thermostats, the Sensi Lite is reasonably priced without compromising on performance.

In terms of durability, it's worth noting that after two months of use, the touch screen on one user's thermostat stopped working. However, this was a used unit, and they were able to obtain a refund from Amazon within the grace period. To ensure peace of mind, it is advisable to purchase the Sensi Lite as a new unit and consider adding a warranty for an extended period of coverage.

I recently purchased the Asefourik thermostat for my home renovations and I am extremely pleased with its performance. The compact design of the thermostat is one of its standout features and it looks amazing in my dining room. The temperature management is excellent and I have experienced no issues with it so far. However, it is important to note that I have only used it during the summer season and I will update this review if there are any changes during the winter.

One of the things I love about the Asefourik thermostat is its ability to learn my habits and automatically create a customizable weekly schedule. Before I had this thermostat, I would often forget to adjust the heat at night or during the day when I was at work. But now, I hardly have to touch it as it takes care of everything for me. The remote monitoring feature through the app is also very convenient as it allows me to control the thermostat even when I'm not at home. Additionally, the generated report tracking the amount of heating/cooling called is a useful feature for monitoring changes week-to-week.

In terms of installation, I found it easy to set up the Asefourik thermostat. I also purchased an additional sensor and integrated it with the thermostat, which has helped maintain a consistent temperature in a guest bedroom. This is a great alternative to having to zone the heater/ac unit. The remote access through the app is seamless and I am impressed with all the other devices that can be connected to the thermostat and app. I was particularly intrigued by the app's health monitoring system.

However, I did come across a minor issue with the thermostat initially. It was not reading the temperature accurately and would let the HVAC run for longer than necessary. After some troubleshooting, I discovered that placing a small fan to circulate air towards the thermostat resolved the problem. It seems that the actual temperature sensor may need insulation and be positioned next to an internal heat source. While this workaround works for now, I will continue to investigate the issue.

I highly recommend this adaptor for anyone looking to connect their thermostat or other devices without the need for complex wiring installations. It is truly the easiest and quickest solution available.

I have tried multiple power supplies before, but none of them worked until I found this adaptor. I'm not sure what the difference is, but this one instantly provided the required power. It's reliable and efficient.

When I moved into my new home, I was worried about how to use my Nest thermostat because my system didn't have a C wire. However, this adaptor came to the rescue. It easily plugged in where the C wire would normally go, and I was able to use my Nest thermostat without any issues. The fact that it has a long cord is also convenient, as it allows for flexibility in positioning.

In addition to using it for my thermostat, I also purchased this adaptor for my Ring Doorbell 3. I was tired of constantly changing the battery, so this adaptor was a great upgrade. It keeps my battery at around 90% consistently, and I no longer have to remember to change it. It's a reliable solution that ensures my Ring Doorbell is always functional.

I am extremely satisfied with the length of this cord. It is significantly longer than my previous cord, allowing me to easily reach a plug without the need for an extension cord. The additional 6ft has made a huge difference for me, especially since I am unable to drill into the wall and have limited access to outlets. It functions flawlessly and is now conveniently out of my way.

This product is an excellent solution for powering a ring doorbell without the hassle of installing a lower voltage breaker in your electrical box. Simply plug it in at the nearest outlet and route the wire to your ring device. The challenging part is getting the wire to your ring device. I personally used this cord for my ring doorbell at my rental property, which required drilling a hole through a brick wall. Once the hole was drilled, I had to carefully fish the wire through the wall. After positioning the plug next to the outlet, I trimmed the excess wire and connected the wires to the ring. Finally, I plugged it in. If this were a thermostat, the process would involve drilling a hole in the wall below the thermostat near the baseboard. From there, you would fish the wire through the wall and come out through the hole of your thermostat. The wire can then be routed along the baseboard to an outlet, and you can use a wire cover/guard to protect it. Fishing the wire through the wall is undoubtedly the most challenging aspect, but there are numerous online videos and tools available to assist with this process. Despite the difficulty, this product is excellent. However, it should be noted that achieving a visually appealing installation can be a bit challenging.

I recently decided to retrofit my gas fireplace/stove unit in the basement with a smart WiFi Sensi thermostat. To accomplish this, I needed a 24V AC power supply that could handle ample current, and this unit fit the bill perfectly. I was able to mount the thermostat at a more suitable location, away from direct heat that could affect the overall temperature of the space. I then routed the power supply wiring underneath the bottom edge of the baseboard trim and over to the gas valve of the fireplace. The wiring process was relatively straightforward, as I found the correct wiring configuration and connections through a quick Google search.

After setting up the Sensi thermostat, I now have the convenience of controlling my fireplace/stove through the Sensi app. Furthermore, I have paired it with Alexa (Amazon Echo devices), allowing me to control it using voice commands if desired. I only wish I had made this upgrade years ago.

I recently experienced an issue with my touchscreen Honeywell Wi-Fi Thermostat where it would reboot every time the furnace kicked on to heat the house. After connecting it to the C Wire Terminal on the furnace circuit board, it worked fine for about 6 months before the reboots became more frequent. It turns out that the furnace's 24V power supply was experiencing a voltage drop when the heat kicked on, causing the thermostat to reboot and preventing the heating cycle from starting.

In search of a solution, I purchased an inexpensive 24V Transformer from Amazon. I disconnected the thermostat from the existing furnace C Wire Terminal and found a spare pair of wires in the wall running upstairs to the thermostat location. I connected the transformer wires to the spare wires in the wall, plugged the transformer in next to the furnace in the basement, and voila – the heat was back on!

I am extremely pleased with the performance of this transformer. It functions perfectly and has resolved the rebooting issue with my thermostat. The price was excellent, making it a cost-effective solution for anyone in need of powering up their Wi-Fi thermostats. However, it's important to note that this may not be the ideal solution for everyone, as it depends on individual circumstances. It worked well for me after exhausting other options.

Additionally, I found this transformer to be a great solution for those who are unable to drill holes for new wires or prefer not to have visible wiring. It's as simple as connecting the wires and plugging the transformer into the wall. I've been using it for over a month now with constant use, and it continues to work flawlessly.

If you find yourself in a similar situation where you are unable to locate or access the existing transformer, I highly recommend giving this solution a try. It has proven to be a reliable and effective alternative. Just remember to do your research and ensure you understand the electrical connections before turning the power back on.

I recently purchased the Honeywell RTH7600D thermostat to replace my outdated mercury analog thermostat. I had several criteria in mind when choosing a new thermostat, including price, features, brand name, and overall reviews. The Honeywell RTH7600D met all of my requirements, and I am very satisfied with my purchase.

The package came with everything I needed for installation, including wire flags to mark each wire before removing them from the old thermostat. This made it easy to identify where each wire needed to go in the new thermostat. The installation process was straightforward, and the included manuals were clear and helpful. Even though I have a gas furnace and AC, which made it a four-wire job, I found the installation to be relatively simple. However, if you have a more complex system, it's best to hire a professional to ensure a proper installation.

Setting up the thermostat required reading the manual, as certain functionalities are code-driven. However, once I went through the setup process, I found it to be easy to navigate. The only minor inconvenience was that changing the date can only be done through the numbered setup, rather than the normal screen setup. However, since it's a one-time setup, it's not a significant issue.

Programming the thermostat took some getting used to, but it wasn't difficult once I familiarized myself with the process. The thermostat allows for individual daily settings with four time slots for different temperature ranges. I appreciated the ability to program multiple days at once, as it saved time. Overall, programming the thermostat wasn't overly complicated, but it did require some patience compared to my other thermostat.

The screen quality of the Honeywell RTH7600D is excellent. It is easy to read, well-lit, and has perfect touch sensitivity. The green glow of the screen may be considered outdated by some, but I purchased the thermostat knowing this, so it wasn't a problem for me. The touch-sensitive areas along the bottom and right side of the screen are responsive, and the buttons are large enough to navigate comfortably.

In terms of functionality, the thermostat has been working well for me. I haven't experienced any issues with constant cycling on/off, and the temperature accuracy is significantly better than my old mercury thermostat. However, I installed it in late September, so I haven't tested it during extremely cold weather yet. I am confident that it will perform well based on its current performance.

In terms of build quality, the materials used are good. The plastic housing feels a bit flimsy, but once mounted on the wall, it doesn't move during regular use. The electric contacts are secure and firmly in place. I did have to adjust the screen position after installation, as it seemed to be held in place only by the pressure from the cover. I gently slid it back into position, and it has held firmly since then.

I recently had the opportunity to try out the Lux Power Bridge for my HVAC system, and I must say, it exceeded my expectations. My previous thermostat operated on batteries and did not have a common wire, which made it difficult to upgrade to a Nest thermostat. After some research, I came across the Lux Power Bridge on Amazon, and its affordable price made it worth a try.

The Lux Power Bridge comes in two parts – the Power Bridge Adapter, which goes on the HVAC Control Board end, and the Split Wire, which goes to the thermostat. The installation process was straightforward, thanks to the clear instructions provided in the installation guide. I followed the steps as directed, and to my delight, it worked flawlessly.

One of the main benefits of the Lux Power Bridge is that it provides a constant voltage greater than 3.90 V to the Nest thermostat, ensuring its proper functionality. Additionally, I was able to run my HVAC fan independently without turning on the compressor or heat furnace. This flexibility was a major plus for me.

While the Lux Power Bridge worked well for my needs, I would like to mention that it may be more cost-effective to opt for an 18/5 wire and run it to the thermostat if possible. This is especially relevant for those looking for a long-term solution. However, if you're looking for a quick and affordable fix, the Lux Power Bridge is a great option.

Another advantage of the Lux Power Bridge is its simplicity of installation. I wanted to upgrade from an old mercury thermostat to the Nest E, and with 4 wires running from the basement to the second floor, I didn't have a common wire. Thankfully, I was able to use my G wire as a common wire, but I did lose independent fan control. The Lux Power Bridge came to the rescue, saving me the cost of hiring a contractor and the frustration of trying to run a new wire. It integrated seamlessly with my system, and everything now works perfectly.

I should note that it's essential to ensure that your HVAC system supports a C wire before using the Lux Power Bridge. Some negative reviews I've seen seem to be a result of attempting to use the Power Bridge on an old system without a C terminal. It's important to understand the compatibility requirements beforehand.

I recently purchased a Wi-Fi thermostat without a C-Wire, and I was initially concerned about the installation process. However, this thermostat eliminates the need for a C-Wire as it runs on batteries. I was able to easily wire it myself by following the instructions and taking pictures of the old thermostat's wiring before removing it. I took precautionary measures while drilling a hole for installation to avoid damaging any wiring. This thermostat offers multiple settings for different times of the day, making it convenient for scheduling temperature adjustments. The programming process was made simpler by referring to the three-digit codes mentioned in the back of the booklet. Overall, I have been using this thermostat for about a month and I am still very satisfied with its performance.

When I decided to replace our old analog thermostat, I initially considered purchasing a "smart" version. However, I realized that I already had multiple Alexa devices in our home, and adding another voice-controlled device would only add to the chaos. Additionally, our reliance on satellite internet made me skeptical about the reliability of a smart thermostat during inclement weather. I also read reviews about people having trouble overriding the smart thermostat's temperature settings, which made me hesitant about investing in one. Considering Honeywell's reputation for producing quality products, I decided to opt for a more cost-effective yet still smart thermostat.

So far, I am pleased with my decision. The installation process was simple as we only had a basic two-wire system, and my husband had no trouble setting it up. We did need to use some extra washers to ensure the unit sat properly on the old wall plate, but it was a minor adjustment. The fact that this thermostat runs on batteries is a bonus for us as we live off the grid and prefer devices that don't consume constant power. Programming the thermostat was relatively easy once we got past the initial learning curve. The only inconvenience we faced was the backlight turning off quickly during programming, but it was manageable.

Since we have in-floor radiant heat, we decided to disable the learning feature of the thermostat. We found that it took a long time for the house to reach the desired temperature if the thermostat anticipated the need for early heating. By setting the thermostat to turn on at 6 AM and off at 9 AM, we were able to have warm floors in time for our morning showers without any unnecessary propane usage. We are extremely satisfied with the performance of this thermostat and have even ordered a second one to replace the control for the other half of our house.

I recently purchased the Honeywell C-Wire Adapter for my HVAC system, which is 18 years old and did not have a "c-wire" or extra wire at the thermostat. I had previously installed a Honeywell WiFi thermostat using the fan wire as the "c-wire," but this meant losing the ability to operate the unit in fan-only mode. After researching online, I came across the Honeywell C-Wire Adapter and decided to give it a try.

Installing the adapter was relatively easy and took about an hour for the first one, including the installation of the WiFi thermostat. Since I had already done it once, the second installation only took half the time. I highly recommend these adapters for systems without a "c-wire" or spare wire.

For zoned systems, it is important to note that the adapters should be installed between the zone control panel board and the thermostat, not between the HVAC control board and the zone control panel. Additionally, each thermostat on the zone system will require a separate c-wire adapter.

The Honeywell C-Wire Adapter allowed me to install WiFi thermostats and retain the fan-only mode without the need for costly rewiring. This is particularly useful for older HVAC systems that do not have enough wires in the thermostat cable. Instead of pulling new cable through the walls, which can be a hassle, the adapter provides a convenient solution.