InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website. How do we know what kind of thermostat is installed and what voltage it requires? Where do we find the thermostat's power source how do we know if it's getting power? How do we diagnose and fix a blank thermostat display? Page top photo: a basic room thermostat showing the red and white wires being switched by the thermostat and a place where it's easy to check for voltage at those terminals.
Most room thermostats on heating and cooling systems receive their 24V DC electrical power from a low voltage transformer that itself is usually found at the boiler or furnace blue arrow in our photo at left. The voltage transformer or power supply may also be supplied from a transformer located inside the heating boiler or furnace or inside its primary controller, as we show in the next photograph below.
Here is a photo of the interior of a primary controller for a heating boiler, a Honeywell LE Aquastat. At the lower left corner of the control you can see a low voltage transformer that can power a thermostat or in some instances a circulator relay or zone valve.
Watch out : some room thermostats require a battery to operate at all. These wall thermostats do not use power from the 24V thermostat wiring system and its low voltage transformer, and typically these thermostats will have larger batteries than those using battery power only for temporary backup. To understand which wires carry voltage to and from the thermostat which is itself acting as a simple on-off switch on that circuit you'll want to check the wiring instructions for your thermostat, or you can see any of these articles on thermostat wiring:.
On 1 - by mod - which thermostats include surge protection?
Lyn there are some thermostats, usually in commercial applications, that have surge-protection capability such as the TPD-SLP Series from. It might. You'll certainly know when you shut it off if there's no voltage on a thermostat wires. If you can find the Transformer that's powering the thermostat you'll see where that's mounted and follow those wires back to your panel and you'll see the circuit that's powering the Transformer and therefore that is powering the thermostat.
I'm changing out a old thermostat. Slide lever style thermostat to a digital one. On - by mod - What would cause this lower than expected voltage reading? Bret Sorry for the delayed response, I've been out of electronic, computer, and cell phone range. If we assume for a moment that the measure was having properly done and safely done so that you don't get shocked or killed then you're absolutely correct that no residential property in North America would be normally receiving just 66 volts of power.
Worse, more immediate and more serious, is that the cause of that voltage drop could be unsafe service entry wiring which means that somebod could be shocked or killed. A damaged power line Transformer, a damaged wire, a leak to ground, are examples of possible causes of trouble.Smart thermostats are becoming increasingly popular with homeowners because of the energy savings they can provide and the convenience they offer.
They can allow you to easily set up a heating and cooling schedule, allow you to control your system when you are away from home, and more.
When we think about high voltage climate control systems, smart thermostats are not something we relate them with, much less automation in general. Energy efficient and at your beck and call, a smart thermostat can make your life easier even when controlling high voltage systems. Smart Thermostats for Heat Pumps. Homes in the northern United States tend to have high voltage heating systems. Many high voltage systems are baseboard heaters throughout a home.
However, in-floor heaters and forced fans are not abnormal for high voltage systems. Smart Thermostats for Electric Baseboards. The fallback of a high voltage system is that there is a thermostat in every room. But, if that is how your home is made up, how is that your fault?
The cost to automaton may be more significant, but the savings are huge in the long run. Seeing a positive return is what most of us want.How to install Nest Thermostat 3rd Generation - UK
With multiple options available, you no longer have to search in vain for smart thermostats that are high voltage compatible. Each year, the technology evolves to add more options and more features for thermostats for both types of systems. Best Smart Home Devices. Wi-fi capable smart thermostats are a dime a dozen. But, other features perhaps will spark your curiosity when looking for a smart thermostat that works with your high voltage system.
There are additional features on the horizon for smart thermostats. It will use usage data, and information about how long it typically takes to cool or heat your home to help you stay ahead of any costly maintenance issues. If your thermostat detects any problems your thermostat will send you an email notification and can even help you set up a repair appointment. If you have more detailed questions contact Protect America. Especially if you are considering a smart thermostat as part of a larger smart home system or home security system.
They will answer any and all questions while assisting you with customizing a smart home system that works for you. They even have staff on hand to help you with the install of your new devices. No question is considered dumb, and all queries are treated professionally and with respect for your safety and comfort. The second question Smart Home Tech Tips.
Products from Amazon. Search the blog search. Home Security Buying Tools security How much home security is right for me? Other Smart Home Articles. Does Nest Work with Alexa?However, heating and cooling systems in North America take many forms. If you have a low voltage system, congratulations — your system meets the most basic requirement for a smart thermostat! The rest of the heating and cooling systems detailed in this article are not compatible with mainstream smart thermostats.
These remote-controlled wall-mounted units are called mini-split systems. They can be used to heat or cool a space. A smart thermostat offers both…. Smart thermostat manufacturers love to tout their energy-savings capabilities - but you've got a role…. Thank you for writing this guide…it helps a lot. This article answered many questions the customers of Vine Smart Thermostat.
I would like to have permissions to have a link to this article from our support webpage…. Thanks again. I just wanted to reach out to draw your attention to our new product, the Mysa Smart Thermostat! It was designed for line voltage heating systems like electric baseboard and fan-forced heaters.
If you have any questions please shoot me an email blayre getmysa. Hi, I just got a Honeywell Lyric T-5 smart thermostat. There is another white wire on C at the air handler probably going out to the condenser along with a red wire. Is there anything we can buy that will work? Thanks for the help! I currently have a lux txe 7-day programmable thermostat has batteries. The manual says it only runs on 24 volt furnaces and no other higher voltages.
There is no option to connect a C wire, nor is there a C wire in the wall. I only have 2 wires connected to the base plate and have no other wires. I also have baseboard radiant heaters have a hot pipe running through the middle of grates covered by a metal housing. Can I use a smart thermostat? Which smart thermostat do you recommend. My furnace is in the basement.
I am a renter and do not have access to the furnace.
Also, I would not be able to run wires. Any suggestions?Joinsubscribers and get a daily digest of news, geek trivia, and our feature articles. Also note that it may be against the law, code, or regulations to do this without a permit, or it might void your insurance or warranty.
Check your local regulations before continuing. The Nest Thermostat is one of the most popular smart thermostats on the market, mostly thanks to its unique design and easy-to-use user interface. So if you tend to turn down the heat when you go to bed and turn it back up when you wake up, the Nest will learn this and do it for you, without you having to program it manually.
If you see a handful of tiny wires in all sorts of different colors, then you likely have a low-voltage system, but if you see only larger wires that are connected with wire nuts, then you likely have a high-voltage system. You can also look on the thermostat itself to see how many volts it is.
Locate your thermostat and turn it off. You might also have to turn off a third breaker for the wire that gives the thermostat power. Next, remove the thermostat body from the wall. This next step is important. Take a photo of the current wire setup and note where each wire is running.
You can also use the included wire labels in the Nest instructional booklet to mark the wires, but taking a photo and noting where the wires go is good enough. Next, unscrew the wires from their screw terminals using the screwdriver that came with your Nest. If there are any jumper cables i. Take the Nest base plate and put it on the wall where you want the Nest Thermostat to go. Use the built-in leveler to make it level. From there, use a pencil and mark where the two screws need to go—one on the top and one on the bottom.
Otherwise, the included screws are self-tapping and can easily be driven into drywall without pre-drilling. Take the two screws and drive them into the wall, making sure that the plate remains level as you do so.
To insert and secure a wire, press down on the button and insert the wire as far as it will go. Then lift up on the button. Next, take the main Nest Thermostat unit, making sure the Nest logo is at the top, and then simply push it in until it clicks into place. Go back to your breaker box and turn the power back on to every breaker that you turned off. Your Nest Thermostat will automatically boot up and the setup process will begin.You may not be alone.
A recent update to the Nest operating system version 5. This issue has actually hit the Capital Mac Service Nest thermostat, so, it seems to be a pretty widespread issue. A manual reset of the Nest thermostat seems to be working for most people with these annoying issues. Wait a few moments and note if the Nest turns itself back on or not. If not ours did notsimply press the Nest again for a few seconds and it should turn back on. You should now see the Nest startup animation and hear a few click sounds—leave the Nest alone until it gets to the main operating screen.
You may lose some unsaved energy data by performing this step. If your Nest is completely off and seems dead or unresponsive, the previous steps will not work for you. Instead, perform these steps if your Nest is completely turned off and will not turn back on. Which cable will depend on which Nest version you have. When you have removed the Nest from the wall and secured the proper cable, you can plug in the cable to the back of the Nest and the other end into a working computer.
This step could take about minutes to charge the Nest back to working status.
Smart Thermostats for High Voltage Systems: What are your options?
Disconnect the Nest from the USB cable and hold down the Nest ring for about 10 seconds, or, until the display goes black. Press the Nest ring again to turn back on the device and release.
You should now see the Nest animation as it starts back up. After it starts up, plug the USB cable back in to finish charging the Nest.
This step will take about 1 hour to fully charge the Nest. After an hour of charging, return the Nest to the wall and it should resume working.
At this time, the battery may still not be strong enough to get the Nest connected to your network—this is normal and eventually the Nest will charge itself up enough to return itself to the network.If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you. Log in or Sign up. DIYnot Forums. Hi All, Hope I am posting this in the correct area. I currently have a fixed wired Honeywell TB thermostat which I am looking to replace with the Nest.
The Honeywell thermostat is a high voltage V thermostat, but the nest is a 12V thermostat. I just have a few wonderings at the moment Can I put something in the wall before redecorating and replacing thermostat to step the voltage down from V to 12V to then connect to the back of the nest.
I am assuming that as long as the voltage is step down, the new thermostat can be easily fitted as it would simply use the call for heat function providing the boiler is in "Always On" mode? How does the call to heat function work with a fixed wired thermostat - is it just a signal wire to tell the boiler to switch on and off?
Thermostats - Do I Need a Common Wire (C-Wire)?
Any help and guidance would be very much appreciated. Many thanks, BrennaBoy. BrennaBoy4 Dec All of this has already been discussed in detail, on the plumbing forum. Helpfully it includes extracts from the NEST installation manual. If you can't understand it then you'll need a NEST installer. Taylortwocities5 Dec According to the above link the nest is 12 volt as the OP said.
I think the US ones are 24V? AndyPRK5 Dec Please expect a longer than normal response time as a result of recent current events. We appreciate your patience and understanding as we work to provide support as quickly as possible. We encourage you to use our online Help Center and Community Forum for additional options during this time.
The online Compatibility Checker has full instructions to see if your heating and cooling systems are compatible with Nest thermostats, but here is some additional information to help you as you use it.
How to tell if your system is Nest thermostat compatible
There may be a switch on your system or near your system that looks like a regular light switch. If you have an older thermostat there may be a mid-plate that also needs to be removed to expose the wires. Learn about thermostat mid-plates.
Look closely at the end of one of the thermostat wires. You may need to pull one out of the connector to check.
The method may depend on your local electrical code requirements. Learn more about identifying thermostat wires. It can be hard to determine which set of labels to use in the compatibility checker.
Read the following article for more information:. Simply enter which connectors have a wire and ignore the color of the wires. This is because not all systems are connected to the thermostat with the same wire colors. The label on the wire connector is what you should enter. Important: Professional installation is recommended for some systems since their wiring and setup can be complicated. These include:. Costs can vary depending on how difficult it is to route a new wire through your walls.
When the Nest thermostat needs a C wire. Nest thermostats are compatible with zoned systems, including zoned systems with dampers. However, there are some zoned systems that require a C wire to work with a Nest thermostat. For more details, please see the following article:. How the Nest thermostat works with zoned systems. Learn more about the star connector. Millivolt systems are typically wall heaters or floor heaters and use electricity or natural gas.
These systems use much less electricity than low voltage systems and can't deliver the right amount of power to Nest thermostats. Remote sensor wires are typically used to give your thermostat outside weather data. Even if your system has sensor wires, it may still be Nest compatible. Systems that use micro-controllers instead of relays are sometimes more sensitive to power sharing. If you have a micro-controller based system, your Nest thermostat may need a C wire to be compatible with these systems.
These systems are sometimes called high impedance systems.