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HRV Installation with the Ecobee3 - No C Wire - Using PEK - Green Wire (Fan) Issues

Godman84Godman84 OshawaMember

I'm unable to have my HRV cycle on after connecting it to the Ecobee3 during installation.
Everything else works fine.

The issue seems to be with the Green Wire (fan) that was interlocked between the Furnace and the HRV.
Please refer to page 21 of the manual to see the setup of the HRV that has 3 wires.


There were two different controllers previously - one for the HRV and one for the Thermostat.
I purchased the Ecobee3 to combine both of them.

The Red Wire from the HRV Controller is now in the ACC+ on the Ecobee. This wire is then further connected to the Furnace Control Board where the Red Wire would go.

The Green Wire from the HRV Controller is now in the ACC- on the Ecobee. This wire is then further connected to the Furnace Control Board where the Green Wire would go.

The Yellow Wire from the HRV Controller is not connected to anything. I still have this wire connected to the HRV control board. I never removed it.

The Green Wire from the Original Furnace Thermostat is connected to the PEK - the PEK is then connected to the Furnace control board.

That is pretty much it.
What am I missing here?
I'm a newbie when it comes to this stuff, so you'll have to be precise for me to pick it up.

Your assistance would be much appreciated.

Thank you.


  • kevinmcckevinmcc Member
    edited December 2016

    Page 20 has the answer you seek.

    Operating HRV/ERV without an Optional Main Control & Adding Dry Contact Controls

    Jumper 2 to 6 for Hi Speed.
    Jumper 2 to 3 for standby−off.
    Dehumidistat 2 to ACC+ and 10 to ACC- .

    R, G, Y, W should got to furnace.

  • Godman84Godman84 OshawaMember

    Hello Kevin,

    Thank you for your post.

    I understand that we no longer have an optional main control, and that is why you've suggested to hook this up this way.

    I've posted a picture of the HRV control board:

    The wires on the left hand side go to the thermostat (the blue (Y) wire goes nowhere).
    The wires on the right hand side go to the Furnace control board. The black wire was the interlocking wire, that is currently going nowhere.

    Some questions to your message:
    What should be connected to Dehumidistat 2 to go to ACC+?
    What should be connected to 10 to go to ACC-?
    Where would I be able to purchase a jumper? Hard to find one online at a local store.

    Thank you for your assistance.
    I'm a newbie...sorry for so many questions.

  • kevinmcckevinmcc Member
    edited December 2016

    A jumper is just a short piece of wire, maybe 2.5cm - 5cm long. Strip the ends.

    I think I see what you are saying, not enough wires to connect thermostat to 2 and 10?

    Are you sure the Red, Blue, Green goes to your thermostat? I am thinking it goes to a HVR controller, see page 19.

    Can you take a picture of where HVR wires go on furnace? Are other wires sliced in with wire nuts?

  • Godman84Godman84 OshawaMember

    Hello Kevin,

    Good to know that the jumper is just a regular piece of wire.

    Yes, there are not enough wires to connect to 2 and 10.

    The Red, Blue and Green used to go to the stand alone HRV controller. These wires are now connected to the Ecobee3 (except the blue (Y) wire) as I wanted to get rid of it. Here is a picture of the setup at the Ecobee3.

    On the RIGHT side, the Red and Green wire are coming from the HRV board that I've already shown you a picture of - from that picture, they're on the LEFT side. The Blue (Y) wire is hidden in the back somewhere that you can't see.

    Here is a picture of all wires on the furnace - they're in here with all of the other wires:

    There are 3 wires connected to the Furnace Control Board from the HRV. If you look at the HRV board I showed you in the first picture, these are the wires on the RIGHT side of the picture:
    Red Wire - far left
    Black Wire - second last from right - this is the wire that used to be interlocked with the green wire I mentioned previously.
    Green Wire - far right

    I believe all slots in this picture from left to right are R, C, W, Y, G.
    I believe everything connected in the C slot are for my air conditioning as it was installed after the HVAC - there is no C wire running upstairs to the main Ecobee3 unit.

    Hope this helps.

  • kevinmcckevinmcc Member
    edited December 2016

    You got enough wires.

    The Red in ACC+ should go to HRV Controller 2, the Green in ACC- should go to HRV Controller 10. Then take two short wires and connect HRV Controller 2 to HRV Controller 6 for Hi Speed, and HRV Controller 2 to HRV Controller 3 for standby−off. If you want Low Speed instead of Hi Speed, remove jumper from HRV Controller 2 to HRV Controller 6 and place between HRV Controller 2 to HRV Controller 1.

    The wires on Green, Red, and Black on the right of the HRV Controller are not needed.

    You Ecobee will cycle the HRV and run the fan as needed.

    If that works you can get rid of PEK too, just use the spare wires. Maybe the blue that goes to the HRV Controller can be wire nutted to the black and black connected to C at the furnace, and the other end of the blue to C on the Ecobee. I know it maybe confusing, but more colors would help. Maybe wrap black electrical tape on the ends of the wires going to HRV Controller so they are distinguishable.

  • Godman84Godman84 OshawaMember

    Thanks Kevin. I will give that a try in the next day or so.

  • Godman84Godman84 OshawaMember

    Hello Kevin,

    I did what you suggested and it appears to be working correctly. I very much appreciate you helping me out. I went with the low speed option.

    I did not get rid of the PEK though as I believe that will complicate my life even more...

  • kevinmcckevinmcc Member
    edited December 2016

    You may want to put a wire nut on each of the loose wires or wrap with electrical tape. You don't want them shorting out.

    Glad you are working.

  • Godman84Godman84 OshawaMember

    The loose wires are not connected to anything...I removed their connections to the furnace, so there should be nothing to short out.

  • alfredlam0528alfredlam0528 Markham, ONMember

    Hi Godman84, just wondering how has this setup been for you since? Any subsequent issues with operation? I was reading this thread as much the exact same HRV unit (Lennox) as you. I had installed my Ecobee without any ACC wires hoping to leave it seperate/standalone from the HRV control but of course, its not working properly (furance fan doesn't come on when HRV unit invoked). I called and Ecobee support suggesting best thing to do is take wires from the HRV control and plug into the ACC's of Ecobee. Before I embark on this journey, just wanted to see how its working with you.

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