hi James here with the one on our smart home comm beam today we are gonna teach you how to wire up a humidifier with your nest thermostat so what we've got here today is two wiring diagrams one for a traditional humidistat set up that you probably already have if you've got a humidifier in your house and the other one is how you need a wire you your humidifier if you're gonna attach it to nest thermostat so there are a lot of people that have a nest thermostat and a humidifier and maybe connected the nest thermostat and you don't know how to connect the humidifier or you're looking for information or maybe you got stuck or maybe you just left the old humidistat on there to control the humidifier which is fine it'll still work with a nest thermostat at all humidistat but if you want to have everything in one place you want to get rid of that old humidistat and just have a nice clean look at the nest that's what we're gonna teach you how to do today we're gonna teach you how you need to wire up your humidifier so that it'll work with your nest thermostat so to understand how to wire this up you kind of have to understand a little bit of the basics of how your human is a humidifier and humidistat are currently wired so what we've got here is just a drawing of the HVAC system and kind of how a typical humidistat is wired so what you've got is a humidifier a humidistat and your HVAC system and then some wiring so most humidifiers are powered by a plug-in plug that plugs in somewhere near your furnace so that's the 120 volt that runs the actual fan but they have a little valve in them or a contact that then turns on either the fan or opens up a valve to let water into the humidifier so then it will then flow throughout your HVAC system so how that works is you you have two wires on your humidistat and it's a very simple system basically what you have is one wire coming from the R which is power that goes through your humidifier R goes over here up to the humidistat and then goes back down on another wire which is connected to C and these are the terminals inside your HVAC system and how it works is when the humidistat detects a certain humidity or you want to set it to a certain humidity that will close this circuit and it will allow the valve or relay here to turn on your humidifier so it's just that think of the humidistat as an on/off switch basically once it reaches a certain level it will turn off and when it taxi humidity is too low it will turn on your humidifier and it's just a very simple circuit are providing power to the valve or the relay goes through here once this closes because of the text the humidity is too low then you have a completed circuit it will turn on the humidifier and that power flows back to the C wire now here's the thing the nest only needs one wire to work with the humidifier so this setup that you've already got you're like okay I got two wires but I only have one terminal on the nest for a humidifier how do I do that well that's what we're gonna get into so all in the nest there's a variety of different terminals we've kind of abbreviated them here but the terminal that you use for your humidifier is the star terminal okay and there's a setting within the nest that you will lat that will allow you to pick what the star terminal is for once you've got it set up and plug the wire actually plugged in there but with the nest humidifier because the nest is already getting power it already has power coming in from your RH or our watt are wire or our C wire in that terminal all you have to do to complete the circuit for the humidifier to turn it on is provide power back down that terminal and then back down to the C you just have to complete a power loop that goes through your humidifier down to your C so how you have to have it wired is you have one wire coming from the star going down to that valve on your humidifier or the contactor relay down on the humidifier and then on the other side of that valve or contact you need the wire to go from the humidifier down to your C terminal and what we're doing is we're just creating a loop here between the our wire to the star terminal when the humidifier is activated on the nest the power will then go down the star terminal it will activate the humidifier and then from there that power has a path to go back to the terminals inside your HVAC system the C terminal so the our wire you don't have to run an extra R wire everything's shown in the dotted lines is what a typical nest thermostat wiring is the R wire is power you're gonna have that regardless for the power of the thermostat to operate it just normal heating and cooling mode so all these other wires are each that's your power G is your fan wire Y is your AC wire and w1 is your heat wire and those are shown in dotted lines because those are part of your thermostat system that you would have regardless of this humidifier connection and of course those wires all then go back to the wiring terminals in your HVAC system so it's actually really simple to install a nest thermostat with a humidifier it's just if there's a lot of confusing information out there and you start with two wires you really go down to one so you kind of have to understand how it works in order to make this happen so it may very well be that you have a wire that's already wired up like this this our wire here on your humidistat you'll be able to tell because they're gonna be different colors they are and the C wire that go to humidifier terminals in your humidistat sometimes the easiest thing to do rather than mess with this other wire is just take your R wire that's coming from your humidifier switch it over to the C and then take that same wire the our wire that you found and put it on the star terminal there so you may actually have to move these over everyone's humidifier is wired a little bit different but the circuitry for a humidifier is the same these things are powered externally by 120 volts to move the motors and everything but the relay in contact is low-voltage inside or the little valve that opens the water up for your humidifier so all you really need to do is make sure that you have a circuit for power for the humidifier so just like we've shown power coming in our that's your normal thermostat power wire and it goes back out through the humidifier you just need to make sure that when you have your humidifier set up that this wire provides a continuous circuit down to the sea wire so that when power is sent from the nest to the humidifier it has a place to go from the humidifier backed out to the sea wire to complete a circuit so the nest when it calls for humidity it will actually send a signal a power signal 24 volts down this humidifier wire otherwise it's unpowered until there's a call for a humidity so once you've got it set up you can test it by turning the humidity up way up to you know like sixty percent or whatever it is the maximum limit on is on the nest you can go stand by your humidifier and typically you'll hear either a fan click on or you'll hear the valve click when you're doing it so that's a good way to check what's going on you could also use a multimeter for all this to check continuity and where the wires go but that's a little bit more complicated it's easy enough if you just follow the wires that you've got here and your existing humidistat and then convert that over to the wiring diagram that I've got shown here for the new nest humidifier so we hope that you enjoyed this video please like and subscribe to this channel we get all kinds of great smart home content you can also visit us at one our smart home comm check out our website and click on any of the links below if you want to support us that's always very helpful to help us keep making you great channels give you good content and we hope this helped you if you have a nest common water issue or any kind of nest wiring diagram issues or an SLO and you want to learn how to do that please click on some of our other videos we've got some great information there that show you how to do that so thank you like and subscribe and we will see you next time