If you're posting a request for installation help, please provide as much info about your system as possible. For example, for help regarding connecting a smart thermostat, please include details about your system including whether you have gas/electric, heat pump, number of heat stages, A/C condenser, etc.

ecobee 3 Install Help Thread



  • PantseatflyerPantseatflyer NW ArkansasMember

    Just got a new Ecobee3.

    My unit is an Amana 80 which is dual heating (gas) and air.

    I would appreciate some assistance with the install.

    As you can see in this pic, there is no "C" terminal, I assumed I would need the PEK unit. Note the jumper between "R" and "RC"

    Here is the control panel. I'm a little confused about the "C" terminal as well as the white and yellow wire combined. How would I connect all these wires to the PEK?


    Any help would be greatly appreciated.

  • PantseatflyerPantseatflyer NW ArkansasMember

    After a bit more research, I assume that the red and white wires that are going off on their own could possibly be going to my external A/C unit. What I would need to do is just leave those two wires alone and then connect the PEK unit per spec.

  • EFTCEFTC CanadaMember

    If you look at the picture carefully, there is an extra wire that is looped around the bundle of wires going to your thermostat. You can pull that wire and use that as the C wire. Go to your thermostat and locate that wire and mark it as C. label the rest of the wires and remove the old thermostat. Connect that wire to the C terminal of your Amana 80 and the other end to the C terminal on the Ecobee 3. With the above setup, you won't need the PEK unit.

    On, and Yes, the top 2 wires are for the AC. AC uses C and Y wires. In your picture, the TOP RED wire should be connected to the C wire on the furnace board.

  • PantseatflyerPantseatflyer NW ArkansasMember

    @EFTC said:
    If you look at the picture carefully, there is an extra wire that is looped around the bundle of wires going to your thermostat. You can pull that wire and use that as the C wire. Go to your thermostat and locate that wire and mark it as C. label the rest of the wires and remove the old thermostat. Connect that wire to the C terminal of your Amana 80 and the other end to the C terminal on the Ecobee 3. With the above setup, you won't need the PEK unit.

    On, and Yes, the top 2 wires are for the AC. AC uses C and Y wires. In your picture, the TOP RED wire should be connected to the C wire on the furnace board.

    Wow! Thanks for pointing that out! I now see the blue wire wrapped around the wire bundle in the furnace. So that the extra wire to connect to the "C" terminal and then at the thermostat, connect it to "C" of the Ecobee3. Saves me from using the PEK! Awesome! Thanks!

  • kevinmcckevinmcc Macomb, ILMember

    Like EFTC said, just make sure not to disconnect the red wire from that AC that connects to C. Add the spare blue wire are you should be good to go.

  • EFTCEFTC CanadaMember

    Always my pleasure

  • QuinnLZ89QuinnLZ89 Saint Charles, MOMember

    Hi All -

    I'm looking for a solution to a frustrating problem I've had while trying to install my Ecobee3. I've included pictures of the wiring of my old thermostat, as well as pictures of the HVAC board. I've had to re-connect my old thermostat, as all of the combinations (PEK, no PEK, etc.) haven't worked with my Ecobee3. So, what you're seeing in these photos, is how everything is currently wired, and functioning correctly.

    As you can see, on my board the blue wire attaches to the C terminal. At the thermostat, there is no C wire. I have Rh jumpered to Rc, Y, G, and W. Here are a few things I've tried:

    1. PEK - connected the four HVAC wires to the PEK - R, G, W, and C in. Then, I connected the PEK wires to the board (R, G, W, Y - which wasn't connected to the board before, and C). The thermostat powers on, both heat and cool appear, but no matter how low you set the temperature, no cold air comes from the vent.

    2. No PEK - The first failure led me to believe that the C in the HVAC must be connected to the outdoor AC unit. I kept that connected to the board, and wired the HVAC back to its original setup. However, in this situation, no power went to the Ecobee3.

    3. "Half-PEK" = Kept blue C wire connected to board. Sent other HVAC wires into the PEK and connected outgoing PEK wires to the board (now two wires attached to the C-terminal). I thought I'd cracked the case, as the Ecobee3 powered up, and I heard the outdoor AC unit kick on, BUT this caused the blower fan to be inactive, so no air was coming out of the vents.

    These were my best guesses, and I tried a few other configurations, but I ultimately gave up, as it was hot outside and I couldn't think of any other possibilities. Does anyone know what to do? I think the outdoor AC being connected to the C-terminal is causing me problems, but I don't know a workaround... Any help would be great!!

    Image Links here:
    ![](https://ibb.co/myLLDF https://ibb.co/ctprLv https://ibb.co/j6mhSa https://ibb.co/kYxBLv)

  • kevinmcckevinmcc Macomb, ILMember

    @QuinnLZ89 said:

    I'll try to help you in the other post. Have to get all the wiring sorted out first.

  • QuinnLZ89QuinnLZ89 Saint Charles, MOMember

    Appreciate it! Sorry the photos are rotated the wrong way!

  • kevinmcckevinmcc Macomb, ILMember

    @QuinnLZ89 said:
    Appreciate it! Sorry the photos are rotated the wrong way!

    Not an problem at all, they were great.

  • itzafugasiitzafugasi USMember


    I purchased an Ecobee 3 lite and have had issues with getting it to work properly for my heat and seprate Central AC.

    My setup is as follows:

    Burnham ES2 Gas Boiler connected to taco 404 zone valve controller, with 3 zones. Zone 1 for first floor, zone 2 for second floor, zone 4 for hot water tank. Ecobee is connecting only to zone 2. Thermostat was wired to Rh and W1 terminals only, which came from Taco zone board.

    Completely Separate Rheem central air unit. Both central air and boiler were wired to same thermostat. AC was wired to terminals Rc, Y, and G. I took spare thermostat wire from air handler to use as common which powered my ecobee.

    I wired ecobee as follows:
    Wires from Boiler: Rh, W1
    Central Air: Rc, Y, G, C

    Here's the issue:
    When I initially set up the thermostat, everything was happy. Heat works. Central air works. After about a day, ecobee loses its connection to the W1 terminal. When I go into the settings-equipment-wiring, W1 is not highlighted, and so it no longer will call for heat. Air conditioner still works fine. If I remove ecobee from the wall, wait a few minutes, and plug back in, the W1 wire reappears and heat works again.

    I spent several hours on the phone with ecobee support, and they provided me with a workaround to connect to W2 terminal, and manually select W1 to trick ecobee to think I had a 2 stage boiler. They thought I had a bad W1 terminal on the ecobee.
    It worked for a few days, but then my Taco zone controller had a constant thermostat light for zone 2 which made me uncomfortable. So I took ecobee out and am back to my original, typical honeywell digital thermostat.

    Given the information here, does anyone know why my system would behave the way it was? I'm willing to troubleshoot a bit, but not at the expense of damaging my hvac equipment.


  • kevinmcckevinmcc Macomb, ILMember

    Definitely sounds like you got a bad Ecobee. Can the swap the unit for a different one?

  • itzafugasiitzafugasi USMember

    Thanks for your reply.
    Ecobee did send me a new one. And I ran into the same exact issue. W1 would just disappear from the settings within a day.

  • hzkobeyuhzkobeyu New JerseyMember
    edited June 15

    Please help. My old Honeywell thermostat have 6 wires and 2 of them connect to W terminal. I have two central A/C units and a oil furnace. Each story has a thermostat and one A/C unit for each story.

    All of Ecobee, Nest and Honeywell technical support told me their systems are not compatible with my current settings. My HVAC service guy told me there is no problem to install the smart thermostat. But I want to install it by myself to save money.

    The image is attached below:

  • kevinmcckevinmcc Macomb, ILMember

    @hzkobeyu said:

    You have a boiler? You have Rh and W from the one set of wires. The other must go to air handler. Do you have more information about your system. Makes and models will help.

  • hzkobeyuhzkobeyu New JerseyMember

    @kevinmcc said:

    Hi, Kevin, Thanks for response.
    I have an oil boiler, the maker is Peerless Boilers, and model is WBV-04-150-WPCTL. It heats up the baseboard, so my heating is not hot air. The A/C condenser is Goodman CLK30-1L. I can't find the air handler information and it is for cooling only.

    Can I just follow my current wiring to Ecobee 4? 2 white wires connect to 1 W terminal and red wire connect to C terminal? Thanks!

  • kevinmcckevinmcc Macomb, ILMember

    @hzkobeyu said:

    If you only have boiler heat, then connect only those wires and not the W that goes to the air handler. Just cap that one off with a wire nut.

    You will connect the Rh and W that go to boiler, and Rc, C, Y, and G to air handler. You look to have extra Brown and Blue wires that can be used for the C.

  • hzkobeyuhzkobeyu New JerseyMember

    @kevinmcc said:

    Thanks.Almost clear, but have few more questions.

    Which one shall I used for C, the brown or blue one?

    Also, the air handler don't provide heating, why still need to connect the white wire to W?

  • hzkobeyuhzkobeyu New JerseyMember

    @kevinmcc said:

    I checked my air handler this morning, and it only has 3 wires connected: yellow, green and red. Please see the image below:

    Then how can I wire Ecobee? Can I use the following wiring?
    Air handle: Rc, Y and G
    Boiler: W and C (from Rh)

  • kevinmcckevinmcc Macomb, ILMember

    @hzkobeyu said:

    No, boiler is a separate circuit.

    You air handler should have another wire for C.

    I believe that wire is the light blue wire we see at the far left.

    Notice the back has a yellow and red? The black must be for Y, they Yellow is Y for thermostat and the red is power going to AC unit outside. The white is likely the C since there is a white wire which is likely the return path to common for the AC unit outside. Try connecting the blue wire from the thermostat to that light blue wire, and be sure not to disconnect the white wire that is connected to that light blue wire or your AC unit won't run.

  • hzkobeyuhzkobeyu New JerseyMember

    @kevinmcc said:

    Thanks again, Kevin.

    I called Ecobee technical support and successfully installed 2 units by following their instruction.

    I connected an unused wire (white) to the light blue wire as C. The previous white wire from air handler is a dummy wire, so I use this as C.

  • Cio-PaoCio-Pao Member

    Hi All,

    I just bough a new Ecobee3 and I would like to connect my bypass humidifier to Ecobee3. I haven't even opened it's box because I am not sure how I am going to connect the humidifier. I know I am going to use the PEK and replacing my current thermostat seems pretty straight forward but I am not sure how I am going to wire the humidifier. Please see attached diagram. As you can see I have 2 wires going to my humidistat and I am confused with the solenoid and the device (perhaps transformer?) wired to the EAC and Nuetral of the furnace board. Can someone guide me please?

  • kevinmcckevinmcc Macomb, ILMember
    edited June 18

    @Cio-Pao said:

    If the humidistat is next to the thermostat, you should be able to wire the orange and brown to ACC+ and ACC-. Make sure before connecting they are actually sending around 24VAC.

    N is neutral and EAC is line voltage, do not connect directly to there. The transformer is for 24VAC, steps down the line voltage. Solenoid is to turn water on when humidity is needed. Often they have own transformer since they can draw more power than available on furnace transformer.

  • Cio-PaoCio-Pao Member

    @kevinmcc thank you for responding.

    I will follow your suggestion to connect orange and brown to ACC+ and ACC-.

    I forgot to mention that there is another wire connected to R in the furnace which I think goes to another transformer that goes to a wall switch to turn on the ventilation manually. Can that be connected to Ecobee3 so I can program the fan to turn on through Ecobee when I want to?

  • kevinmcckevinmcc Macomb, ILMember

    @Cio-Pao said:

    You can configure the Ecobee so the fan runs every so many minutes per hour. The fan will kick on and run every so often to circulate the air.

  • stewartmcgstewartmcg St Joseph, ILMember
    edited July 8

    We have a new construction house - the builder has put in a basic thermostat. I am trying to install an EcoBee3 - most of the wiring is straightforward but the current thermostat has 2 x wires in Y. I tried echat with EcoBee - person said should not have 2 wires in same slot but only said that I will need to figure it out for myself. awesome.
    Do i just copy and put 2 x wires in Y on eco bee? or some other combo?
    I have wires in W, Y(x2), G, O, R (also jumped to Rc but eco bee say to ignore jumper), & C.
    Our heating/cooling is Geothermal.
    Your help would be appreciated. Thanks.
    i have a photo but haven't found the upload photo button yet :-)

  • kevinmcckevinmcc Macomb, ILMember
    edited July 13

    @stewartmcg said:

    No idea why you would have 2 Y wires on same terminal, unless the unit is two stage and they install a cheap thermostat the is single stage.

    If that is the case, you probably want to investigate other end and install Y1 to Y1 and Y2 to Y2, that way you can make use of the low stage.

  • stewartmcgstewartmcg St Joseph, ILMember

    Thanks Kevin,
    correct... a very cheap thermostat... the system failed a couple of times with this thermostat (it would blow but only recycle air in house, didn't trigger geothermal water circulation). they replaced with a nice unit (one wire only per terminal) and i left it to run for a while to make sure the system was stable before i added the ecobee3.
    after a week all was good. i added the ecobee3 this afternoon... going with the wiring Y2/W2/G/W/C/Y/R but this again blew the same air without actually cooling.
    i took a chance and went with the letter below the same terminals, i.e. Y2/Aux/B/OB/C/Y/R which gives slightly different connections on the ecobee compatibility webpage and hey presto as if by magic it works. it is in our new house (we don't live there yet) I will check on it again in the morning but it went off/on when i changed the controls all should be good.
    i should say this time when i fired it up after changing the wiring... the ecobee3 did ask me questions about "Geothermal" so it did recognize the correct configuration. it asked "How is your O/B reversing valve energized" i left it at the default "on cool" i just found advice elsewhere including the EnerTech website saying this unit should be sent to "on cool" so again all good.
    Thanks for your help.

  • AlexK91AlexK91 Member
    edited July 17

    Hey guys,

    I purchased an Ecobee 3 Lite a few weeks ago and have finally got around to installing it but have run into some issues. Using the app to select the current cables I have in my thermostat results in the app telling me my system isn't easily compatible and it needs more information.

    I've tried using the phone support but they weren't very helpful so I'm hoping I can get some help on here.

    My unit is a Trane XC95m (ComfortLink II), I've attached pictures of what cables I currently have connected. Please let me know what I can do to get this system working. Thank you.

    (the letter covered by the green cable is B)

  • LarrylLixLarrylLix Northern Southwestern OntarioMember
    edited July 18

    You appear to have no heating connected in your HVAC unit. The W1 and W2 are for two stages of heating if you're HVAC capable. Are you in some warm climate where you never need heating?

    I have not seen a B/C combination before but probably mean Black wire or Common.

    Here is how I remember the wire colours

    R = Red = Hot = 24vac
    Wx = White = Warm
    Y = Yellow = Yank heat out = A/C
    G = Green = Grill = fan
    B = Black = 24vac common (C)
    D = Never heard of it before

    Your green wire is connected at the old stat and not at the HVAC unit = no function

    Actually the two ends shown are from different cables. They each have different colour combinations and one has six wires while the other only has five wires.

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