Nest Thermostat 2 Wire Hookup Instructions

Nest Thermostat: amzn.to/38A3QZ1
Favorite Smart Home Devices: www.amazon.com/shop/onehoursm...
In this video we teach you how to hook up the Nest Thermostat with only 2 wires. 2 wire nest installations are typically used for installing the Nest Thermostat on Heat only systems or Boilers.
In most cases the Nest Thermostat will work with heat only or boiler systems. Boilers systems that work with Nest must be low voltage controlled and have control systems which work on approximately 24V.
Typically in a two wire setup the wires are red and white, but not always. It's a good idea to take a picture of your existing thermostat wiring before replacing it with Nest as this is the easiest way to determine where your wires should go on the Nest.
It's important to note that the you don't need a jumper wire on the Nest from Rc to Rh and when using a 2 wire system you can plug the R wire into either Rc or Rh and the Nest will still work. We recommend plugging it into the Rh as this is standard.
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[@anthonysmith9410]

Very well explained. I am a electrician for 43 years and most folks don’t understand that its just a switch

[@blancoschmidt1]

Man, you just solved one of the biggest mysteries in my life.

[@rgonnering]

It is too bad that Nest/Google can't find someone to explain their thermostats. You are the man.

[@ramc605]

Thanks for the great video - I followed your detailed instructions and the Nest is working perfectly!

[@stanmak536]

Exactly what I was looking for including explanation of other colored wires! Thanks!

[@fr33s7yl0r]

I am an engineer and really appreciate people like you and the way you explain things to those who are non-technical. Well done !!

[@agael8]

Thumbs 👍 up, finally something clears out 2 wire systems, thanks Sr!

[@michaelwalker9795]

The best explained so far on youtube, good job.

[@donnamarhefka8746]

Awesome! Saved $110 on Nest install, thank you!

[@mickey17y]

Absolutely great video. Thank you!

[@riyazsf]

Big help! Thank you!

[@joseluiscaceres1458]

BEST explanation I've seen. Super helpful. Good teaching.

[@joey3291]

Thank you, perfect explanation

[@NevisIsland]

Concise and clear. Thanks

[@NipomoBeach]

Thank you, very helpful

[@thejedimaster218]

Nice easy instructions 👌 Great diagram

[@IBEW126]

THANK YOU DAVE💪🏽💪🏽💪🏽

[@evanmost]

This was great! I bought a Sensi, but the same rules apply.

[@everythingnnothingpodcast]

Thank you for sharing.

[@matty2495]

Thank you. This video and explanation were beneficial. I was wondering what to about that jumper.

[@OneHourSmartHome]

You're welcome! Thanks for watching and the comment.

[@windowsforvista]

You are amazing!

[@jbetz78]

easy to understand video. thanks you and thumbs up

[@OneHourSmartHome]

Glad it helped!

[@joshuaperkins3818]

This was great! I have a super old Taco 568-13 thermo for heat. 2 wires: 1 red and 1 white. Sounds like I would just go R>Rh and W>W1, no need for common as I'll be using the Thermostat E model. Now, does having multiple zones change anything? I have 4 separate zones, each with their own thermostat. I plan on replacing them all eventually, but just want to hit the old Taco one first.

[@michaelflynn5373]

Thanks man. You are the best. Only problem I am having now is that it refuses to connect to the internet,.

[@paulwaul2623]

thank you thank you!

[@pibitos003]

Thanks much greatings from Maryland usa I am from El Salvador myb respect .

[@OneHourSmartHome]

Thanks and welcome

[@stevepol613]

Bravo. I also have a cooling system that’s only 2 wires where the thermostat uses 2 double a batteries

[@jerrylachmenar3413]

Great explanation.

[@OneHourSmartHome]

Thanks for watching and the comment. This video can also be helpful: kzbin.info/www/bejne/fKDHdYmOZ7t3fdE shows a complete nest installation with 2 wires. The Nest Gen 3: amzn.to/2NZm5BM and Nest E: amzn.to/39oX3DH in most cases will work without the need for a common wire.

[@munnaroxx]

Great video, very well explained . I have a 2 wire system - red wire and white wire, and I did the exact same thing to connect my nest. But now I have a swamp cooler for cooling during summer, can I connect my swamp cooler to nest ? If so can you please guide? Also , how should I know , if I need a c wire? Currently nest is functioning with 2 wires but not having a c wire, will it cause any issues down the line? Thank you in Advance!

[@AOG_ETH]

Excellent

[@recarecareca]

Gracias!!

[@erikjanssen4449]

thank you. from the `Netherlands. good simpel info for my (Dutch)

[@user-wv7sr2rc8u]

Thanks for the video - it got me thinking, however this workaround did not work for me. I got things working eventually and will describe in the hope it helps others. I have a gas HVAC system (heat only) with electric blower. Installed around 2000 with a Honeywell Chronotherm IV controller which has 3x1.5V batteries. It had two wires connected to W and R. Nest Gen 3 kept turning off with two wires connected to Rh and W - it reported no power to Rh wire. So I bought a 24VAC 1amp power supply from Jaycar and connected as per your other video with three wires. Again thermostat kept turning off due to no power to Rh wire. I then connected transformer to Rc and C, and connected the old wires back to Rh and W. Thermostat had power but it blow only blew ambient air, furnace didn’t come on! I then twisted one transformer wire together with the old Rh wire and just got the now thicker end inserted in Rh, left the other trans wire in C, and the old W wire in W. Hey presto! It works fine and well tested now. Cheers.

[@stevenjerman131]

That answered my question.

[@tarrazu2058]

I have an old thermostat that has two wires. Vg and V+. On the controller it also says Vg and V+. The controller also has all of the Y, W1, Rc and C. I've installed the nest with Vg to W1 and V+ to Rh. The nest is only reading the heating but not AC.

[@gordycolby6612]

great channel.....I have a Nest basic thermostat need for a furnace with two zone requirements...therefore needing two thermostats....currently the main thermostat has 6 wires and the secondary thermostat has 4 wires....the main one has an orange and black wire.....How does the wiring work?....I have another Nest on the other furnace with one zone and 4 wires with easy hookup however just watching your video I know how to hookup the C wire for power..thanks...So the Nest basic has an orange/black port but not both....Confused as to how wire it for two units on the same furnace thanks Gordy

[@BMWExcluserviceRockville]

Great info. I need some help. My workshop has two standalone natural gas heaters.(2 wire system) I also have two residential air conditioners I believe it to be a standard (4 wire?). I want them all on one nest thermostat. In the winter I want it to close/open the circuit to control the heaters without turning on the blower fan that is on the A/C. Can a nest do this and Where would I connect what wires to the nest and are their any internal settings needed for this to work?

[@stormingee]

Better explained than what comes with google nest.

[@chrisrobin564]

Question: Nest support claims 2 wire boiler system will work with Nest 3rd generation and keep battery charged without short cycling. But unless the battery is trickle charging at so low a current level that relay is not fully turned on I read over time it may start short cycling or prematurely wear out the relay by having low current constantly flowing. I don't want to return from vacation and find my transformer and relay are blown. Apparently Bosch-Buderus support said my wall hung boiler isn't supposed to be retrofitted to a 2 wire thermostat, but thats what the installer did and its been fine for 8 years...

[@johnnyAutobot]

I have a 220 base board system with a transformer to a relay switch to the nest, the system has worked over the past 4 years I do get low bat once in a while. How can I add power to the c

[@keithramzan3661]

Perfect video. I have a gas boiler. My thermostat has a R wire that is white and a C wire that is black. Just 2 wires. Will this work with the the basic Nest ( non learning)Model GA01334 or do I need to hook up the C wire adapter? Appreciate any insight. Such a helpful video

[@MrLuescher]

Will swapping the W and R wires break the nest? I have two black wires and not sure which is hot and which is ground.

[@tomclifford2598]

I've got two black wires (one goes to the W terminal and one to the RH terminal), a green wire that goes to the G terminal, a white wire that goes to the Y terminal and red wire that goes to the RC terminal on a White-Rodgers thermostat. I'm trying to replace the thermostat with a Nest thermostat. I'm wondering if I can use the black wire that goes to the RH terminal as the C wire?

[@philb5799]

Using a cadet heater can this be done? The wires to the thermostat are 12ga. I can add a c wire no problem

[@traviscarter99]

I have a 2 wire brivis thermostat that I want to replace with nest. Trouble is it has heating and cooling on two wires. Any thoughts?

[@falima2000]

My furnace only have 2 wires, I am planning to replace the old thermostat to a nest 3rd generation, do I need the C wire or it will works without it.

[@FamilyFirst137]

Question…. I have it setup the way u have it for the last 2yrs and today I got a “e74 not detecting the rh”… everything I saw said it’s your condensation line clogged but I don’t have a condensation line… it’s heat only and it’s radiators .. z

[@wingzfan102]

Just installed a Nest thermostat and am getting an intermittent flashing light on my boiler control panel when the nest is not calling for heat. If I take the nest off the baseplate, the flickering light stops. Any idea on why that would be happening? Just reinstalled the old thermostat and the system is acting normally with no flickering on the boiler control panel.

[@stephenw2369]

Would Nest’s battery be charged with Rh wire when the heat only system is not running during the summer? Thank you.

[@mattdirado6834]

Quick question: in this two wire heating system, would the Nest stay charged during the off season (during summer months)? Thanks for this, super helpful.

[@michael1084]

Would love an answer as well

[@ldenorio]

it will not, you have to connect a "nest power connector" at the furnace, it should supply a low voltage through the red wire

[@sarahball191]

Hi! Forgive my ignorance, as everything I know about this I've learned in the last two hours googling. I have a gas wall heater, with a millivolt thermostat. Am I correct that the Nest will not work with that system because it does not generate enough power to actually power the thermostat? I have a very old thermostat (with mercury) right now that has been failing and want to upgrade to a smart thermo if possible. Thanks!

[@krizma11]

Thank you for your explain.. can you kindly explain if you have 2 wire and need charge nest power.. do you have solution for that ?

[@OneHourSmartHome]

Chris, this video shows you an option: kzbin.info/www/bejne/nZLLgat5mLV3qtE

[@markgeisler7187]

I have a 2 wire cooling only system. Will this hook up work for me?

[@jasonberroa2337]

Thanks for the video. I have a 2 wire system with 4 zones. I have 4 nest E thermostats I just installed. They all work fine however, when they are not calling for heat the oil boiler electrical panel is making a constant clicking noise. Any advice you can offer on how to remedy this would be greatly appreciated.

[@johnoyson]

I have the same issue .

[@av1dgamer]

I only have black and white wires. Should the black go to R1?

[@6fingerdbeast]

I have watched the video and I have a two wire system! The old thermostat had a jumper, so I'm glad you explained it. I had just bought a Honeywell T9 and no matter what I did could not get the boiler to turn on. I am interested in the nest but what model was this based on? Thank you

[@OneHourSmartHome]

The Nest 3rd Generation: amzn.to/3k6Gy1L In my experience will work with most 2 wire boiler systems without the need for a common wire.

[@joshuachavez9086]

I have a two wire system but looks like I have a C wire and R wire. I attempted installing a T9 honeywell with not success. So I ordered a nest hoping this would work. Any idea on how to wire the nest as there is not a W wire currently wired to the current thermostat

[@InfinitePCGaming]

Hooked mine up and the heat only occasionally works. I'll hear boiler kick on but then it turns off a second later. Not sure why it works occasionally. Any one have and ideas?

[@g.o.a.tmedia1745]

Have this setup but nest says low battery and will not charge even off wall

[@johnnytruong1364]

Hi James, my system has Red and Black, not White. How can I connect to the Nest? Thanks in advance for your help.

[@Dtownmami_Cmari]

My wiring is one (thicker) black wire that splits into two wires. (Reminds me of the pull n peel twizzlers candy). One black wire runs to the “W” and the other runs to “RC”. Then I have a red jumper wire that is in “RC” and “RH”. So on the Nest, I don’t need the red jumper anymore. I just connect the one black wire to W1 and the other black wire to RH? I just don’t want to fry the furnace. 😞

[@tmeyer2000]

I have an old Honeywell 2-wire thermostat (mercury switch) hooked up to a relay that switches a 240V load for baseboard heating. There is a spare third wire, that is unconnected between the thermostat and the relay switch in the basement. Is there a way to rig it up with a 24V wall wart transformer to get power to the Nest?

[@ericyeung4330]

My place uses radiant heat flooring. The so-called unit I check is a gas-fired hydronic boiler. It is a Laars Mini-Them II model. I guess I am not a good reader. I was reading the installation manual to find out it's voltage system but I don't know if a 24V or low-voltage system. The wire panel on the unit strangely has R, W and A ports. Only R and W and connected (black and white wires). Anyone can shed some light here? Thanks.

[@mohammedhassanpmpcsm2338]

Hey One Hour, I have watch your video and everything works fine but why doest Nest 3rd Gen say "No Power to Rh with E74 error" then error message goes away? Please help

[@daveatkinson1099]

SO I have an RC and an RH wire on my old thermostat...have separate ac and heating no forced hot air system. the new nest only has an R no RC or RH, MY RH wire is plugged into the R side on my old thermostat so what can I do about this? I have the new nest that only has Y,C,W G,R ,O/B connections

[@armyers4190]

I know this video is old but I need some help. I have a two wire system, red and white wire. I put the red in the R terminal, and white in the W1 terminal. The only options my nest is showing is heat, off, or eco. There is no cooling option. What am doing wrong?

[@suprajohn]

Have a two wiring heating and cooling V+ =red wire and VG = Green wire. Voltage is 3.38 v i know nest requires 24 V to operate do I need a transformer?

[@bigdavie39]

Is the 2 wire system 230-240 volts uk ?

[@anunez1979able]

What would you do if your 2 wires are red and green. My thermostat is really old, which uses a small lever that you move to the right to select the desired temperature. That's what I have in my home. It's heat only, and my furnace uses gas, not oil.

[@alanbarr8301]

you mention that cooling only system is very rare... well we've got one living in a very warm location. so, we are looking for a 2 wire install instruction for cooling only scenario as follows: We are installing new cooling units (Samsung 360 Cassette 46,000 btu model), but we do not have any heating whatsoever as we are in a very warm location year round. The samsung thermostats (model MWR-WE13N) have a low voltage 2 wire connection (labeled F3 and F4) , similar to the 2 wire heat that you just demonstrated. I've tried discuss this with Google nest support and they have been useless. We are looking for a diagram, and advice, whether 2 wire with Samsung products, can be set up on Nest Learning Thermostats. We are also more that happy to add control wire separately to power the thermostat so that isn't the issue here. Any advice? Cheers!

[@captainkowalski5176]

Anyways....lol...mine didn't work when I hooked it up the red wire to the Rh, however, worked fine when I hooked it up to Rc. Thanks for the vid.

[@bitterfunger4897]

Capt - Can I ask what gen Next thermostat you have? I'm using a 2nd Gen with a new Lennox furnace and it's shortcycling. When I remove the thermostat and connect W and R the furnace works fine. Thanks in advance.

[@monchi3121]

I have to 2 wire and the black its brige what do i do in that occasion??

[@steveqto]

Can you do a video on the Trane Thermostat? I am trying to hook up my 2 wires garage heater to it. I only have two wires from the heater but I need a wire to power the thermostat up.

[@OneHourSmartHome]

Steve, this common wire adapter trick should work: kzbin.info/www/bejne/nZLLgat5mLV3qtE here's a link to the adapter: amzn.to/2uZN4TY

[@MindURMeditation]

for two wire heating system can you put W1 for heat from oil furnace and just add a common wire to c and RH to a wall outlet ?? for a oil heating Force air. I have W1 for heat white wire and RH for power but getting low power so the thermostat needs power if I power the thermostat with wall transformer to c and rh then the nest thermostat will take care of w1 and sending power to W1 - call for heat?.

[@johnoyson]

Did you get the answer to this ?

[@dempseydoodles]

I have a Modine heater in my shop and my thermostat currently is a two wire set up (W & R). I have a nest thermostat, and it requires a C wire or a Google Power Connector. How would you wire up a system like this using the Modine heater? I already went ahead and connected the power connector in the appropriate spots according to where the thermostat wires were and I connected the C wire to its appropriate spot. I fired up the Nest Thermostat, and it did not detect the C wire/power. am I supposed to install a jumper wire connecting the C and the R behind the thermostat?

[@ChrisWrightDVM]

I have the exact setup above, only 2 wires, a Nest E, and a navien combi-boiler. The problem? My nest gives an error code for not getting enough power. So what should I do? Any tricks? Run a common C wire through my house to the Navien boiler?

[@JabDFilms]

Dosent nest e come with batteries

[@GiovanniGuiseppeX-XIV]

So I have a miller/ Beckett furnace with a first generation nest.. only two wires running from unit to thermostat… how do I hook up without adding c wire bc there is nowhere on my board for me to connect to.?

[@caryfriedman5676]

Does not work with Nest Thermostat E. Anyone know where to get directions for two wire fhw boiler with Nest E?

[@andyluke3637]

I want to install a nest learning thermostat but my old thermostat has 2 wires only W1 and B (not R). How can I install it ?

[@tinmank]

Have you had a chance to test Wyze? I've 2 wires only (W+R) as well and pricing seems reasonable for that one as well.

[@OneHourSmartHome]

No, haven't gotten to test the Wyze Thermostat yet. Looks like it ships in December 2020. I'll look for when it becomes available.

[@sibin07able]

I have a 2 wire thermostat, I have red and blue wire- I have zoning system, does the Rh W1 still works for me wit the google nest? Hope you answer me.

[@ganthonychaparroful]

Hi I have a the furnace the C and Y wires together. Can I use the Y wire and connect it to the C wire since I'm having problems charging my Nest E?

[@iAmNo0ne]

Can someone answer something for me before I buy a Nest thermostat? I only have 2 wires for my heating and AC. An "R" wire" and "C." I'll be good connecting to Rh and C on the Nest?

[@newhomeownersideas4658]

What will happen if swiped the wires?

[@DBLG65]

If you're just using heat, and during these times your home all day, is the Nest really necessary?

[@davidg5290]

What if you have 2 wires and it’s electric heat and AC - red and white wire? I been searching all day and there is nothing on this.

[@onemartinway]

Thanks for your info. I currently have Y1, RC, RH, C, W/E, and G connected on a Honeywell Thermostat. Can't for the life of me figure out what the W/E wire is for. Anyone have any idea?

[@smixson5682]

W is your heat / Emergency heat if its a Heatpump

[@smixson5682]

W is your heat / Emergency heat if its a Heatpump

[@alejandrodelapenajr.4264]

I have a Honeywell CT 31A1003 connected with only 2 wires which control AC & furnace. I want to replace it with a Nest Thermostat E. Will it work? Just connect the 2 wires to W1 & R

[@jasonohrel4550]

Same here. Anyone know an answer

[@Kristenlg520]

I hooked up W1 RH worked fine all night, set up the app everything was perfect but in the morning it’s now saying no power detected to RH. What would cause this? I checked the wires and they are in fine.

[@joshuaphurkotum9292]

Because r is not constant power. R only has power when boiler is running, that's why the battery dies. You need to connect a c wire. This is not an option.

[@fransiscoscaramanga674]

I have a weil mclane boiler...…..with two wires that put out 14-15 volts dc.. will this work with my boiler?

[@OneHourSmartHome]

Don't know, never run into that particular boiler model, but 14V seems too low.

[@csocsika1700]

hi mate. I have got only 2 wires and 110v. does this R And W terminal will switch it without any issue.? and where to put 24v power for nest e?

[@joshuaphurkotum9292]

You need c. Especially if there is a summer time. When the boiler isn't running, the r terminal has no power. That is why you need a c.

[@elnuh9796]

I HAVE A "T, W, TV" ON MY HONEYWELL THERMOSTAT CONTROL BOARD ON THE HEATING SYSTEM. HAS TWO WIRES HOOKED UP TO T AND TV TERMINALS. ANY HELP HOOKING UP MY NEST TO IT WOULD BE APPRECIATED

[@josephzihal731]

have an argo relay box two nest thermostaos attached with 2 wires works fine added 3rd thermostat now gettig chatter also 2 wires HELP ?????????????

[@danilorodrigue7022]

What is I only have 2 wires C & R on my old Honeywell thermostat?. There is no W wire

[@josephdragan7734]

Please explain the purpose of the built in battery in the Nest e. I have heat only(steam) two wire system. Upon initial install the Nest required a two hour wait for its battery to charge.

[@OneHourSmartHome]

It powers the electronics/wifi chip. Since the HVAC system power provides relatively low voltage the battery is used to help power the Nest E: amzn.to/3gjLxfe durring more power intensive operations which have a higher current draw. Typically you won't need to wait for the battery to charge, but if you got a thermostat that sat on the shelf a long time it's possible the internal rechargeable battery was discharged or that your HVAC system puts out just barely enough power to charge up the battery.

[@josephdragan7734]

@@OneHourSmartHome Thanks, that makes sense.

[@ttate9954]

Hello. We have a two wire system and were elated at first. We now find although we will have the Nest turned off, the heat will come on. Has anyone else had this happen and have any suggestions? We called Nest but they were vague with possibilities.

[@OneHourSmartHome]

If the Nest is off and your heat is on, it might mean that your R and W wires are shorted together somewhere. Touching the R and W wires together will turn on your heat.

[@aeidher]

Thanks for the video. I tried this with a old school 2 wire thermo connected to a fireplace. It didn't work, the Nest didn't power up. Any suggestions? Thank you

[@joebenckert8740]

I'm having that same problem.

[@aeidher]

@@joebenckert8740 search up a C-Wire adaptor in your favourite online store. The 2 wire system doesn't provide enough power

[@engmoukadem]

Hi Dear. I got a smart thermostat but my old thermostat having only 3 wires! Is there any chance to make it works ?

[@engmoukadem]

It’s red ( high) yellow (medium) and black (low) this for the old thermostat. The new smart thermostat I want to install having this codes point one 9# ac220v-l / point to have a group arrow as points #8 ac220v-n . Fan #7 high #6 med #5 low then group arrows mention Valve #4 open / #3 close. So where I connect the 3 wires I have ? Pls help me

[@DavefromCA2023]

“If you didn’t take a picture of the wiring on the old thermostat you can…” Not all hero’s wear capes

[@edgarr4654]

I have the same problem but my wires are R and it’s a red wire and C and it’s a blue wire. From my understanding I will connect the r to RH and C to C correct?

[@joshuachavez9086]

Did you get your HVAC system to work using this?

[@fatboy19831]

On the new google nest thermostat. There is only Y,C,W. And G , R , *OB. . I know the C is common. What two wires should I hook up for the witch to work?

[@OneHourSmartHome]

I did a new video for the new nest thermostat you can watch it here: kzbin.info/www/bejne/r5qYnJmkaMege80 requires a common wire to work. The Nest Gen 3: amzn.to/2X4WbgP is an easier to install option if you only have 2 wires as it does not require a common wire. Here's a full installation video: kzbin.info/www/bejne/fKDHdYmOZ7t3fdE