Author Topic: ecobee 4+ Furnace + AC + HRV  (Read 1257 times)

Offline Garce

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ecobee 4+ Furnace + AC + HRV
« on: July 07, 2018, 10:41:36 PM »
I am trying to figure out the wiring for this.
I have a 4y old home with Furnace + AC + HRV (Vanee). 
Originally, everything was controlled from a thermostat + one button wall HRV controller. This all came with the new home and from memory all worked well. The HRV will turn on the furnace fan when working.
Some months ago a contractor installed an ecobee 3 lite when I was not home (so I dont know what he did). He installed the ecobee 3 lite with the PEK unit. HRV was still controlled by the wall control.
I got an ecobee 4 and wanted to use it to control my HRV (thermostat and HRV control are 10cm away).
I opened the furnace control panel to understand the wiring and discovered this:

PEK                  Furnace                       HRV                                 AC
G           -                G                =            C, NC (see note)
Y            -                Y                                                       -         Y
W           -               W
PEK        -               C                                                         -        C
R            -                R                 -              No

I can not understand the NC connected to G on furnace. That is not how the Vanee indicates should be installed. I removed NC, insulated with tape and left it alone (to align with Vanee instructions).
I installed the thermostat and wired the HRV B to Ecobee ACC+ and G to Ecobee ACC-

Now, AC works: AC equip turns on, fan turns on, cool air comes in
HRV works? Fan comes on but the HRV itself does not make any sound. Also I noticed HRV was not consuming any electricity (I connected it to a smart plug meter)

At this point I am hoping I can confirm wiring is appropriate ?
Does HRV control B/G to ACC+ or ACC- matter?

Thanks!



Offline Admin

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Re: ecobee 4+ Furnace + AC + HRV
« Reply #1 on: July 08, 2018, 12:08:03 PM »
The NC wire coming from the HRV should be maretted to the thermostat G wire, so I'm not sure how the furnace fan is starting when you turn the HRV on, if that is disconnected.  I suspect if you turn the thermostat fan ON, it won't run.  The HRV interlock wiring should be connected as follows,

HRV NC maretted to thermostat G wire.

HRV NO to furnace R.

HRV C to furnace G. (This should be the only wire on the furnace G terminal)

When the B and G terminals close the HRV should run.  Do you have the Ecobee settings changed to have the ACC terminals control the ventilator (HRV)?
If you remove the B and G wires from the Ecobee and twist them together, the HRV should start.  If not there may be a problem with the HRV.

Offline Porcupinepuffer

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Re: ecobee 4+ Furnace + AC + HRV
« Reply #2 on: July 08, 2018, 12:48:06 PM »
The NC wire coming from the HRV should be maretted to the thermostat G wire, so I'm not sure how the furnace fan is starting when you turn the HRV on, if that is disconnected. 

Doesn't he show that he has a G from the furnace board to the G on the PEK controller? But that he just disconnected another wire going from the furnace to the NC of the HRV?

Wouldn't his blower on his furnace just continue to work as a normal as if the HRV wasn't involved?

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Re: ecobee 4+ Furnace + AC + HRV
« Reply #3 on: July 08, 2018, 12:50:45 PM »
I’m confused by how he showed his wiring and why G is connected to both the HRV C and NC.  It sounds like the furnace fan will start with the HRV, heat or cool, but if he disconnected the NC wire the thermostat fan ON may not work.

Offline Garce

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Re: ecobee 4+ Furnace + AC + HRV
« Reply #4 on: July 08, 2018, 02:49:32 PM »
--This is the OP--
(Unfortunately, I don't know how the wiring was when I got the new home. Also I was not present when the technician came to install the ecobee 3 lite. He did left a marrete on the floor... My wife was not impressed by him but he didn't check or have any recollection of what he did)

For clarity, the HRV connector has 
1. a 3 wire cable connected to No, C, NC
2. a 3 wire cable connected to  Y, G, B
I can not follow the cables but do find a cable coming into the furnace control board with exact same colors as #1, a cable coming into the HRV wall control with the same colors as #2

The cable #1 coming into the furnace control panel had:
"No" wire inserted on R (R also has the R input to the PEK)
"C", "NC" wired inserted on G (G also has the G input to the PEK)
I had taken NC and removed it from the G on the control board and left it alone (electrical tape)

I had set the ecobee to control the furnace FAN per recommendation during setup. However I just changed to HVAC and the result is the same 

I can confirm that
Turning on the FAN, does turn on the furnace fan, room temp air comes through vents
Turning on the AC, turns on the FAN and AC runs, cold air comes in through vents
HRV cycle turns on the FAN. Just the HRV itself doesn't look to do anything. I plug it through a watt meter and it consumes 1W whether it is supposed to be running or not.

The HRV manual includes an "standard" configuration which is what I have now (NC not connected)
There is also an Alternate Furnace interlock wiring that has what you proposed, NC connected to G on thermostat (I assume this is the furnace side on the PEK and not the thermostat side of the PEK?)
I didn't try this because the manual implies this is for older thermostats... My house, AC, HRV, thermostat are all very modern

Offline Garce

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Re: ecobee 4+ Furnace + AC + HRV
« Reply #5 on: July 08, 2018, 08:58:56 PM »
Ok, after reading a bit more online I decided to follow the recommendation and do
HRV NC maretted to PEK G wire (furnace side).
Same result (Ventilator on will turn on Furnace Fan but HRV engine will not start).
I opened the HRV and it was very dirty, honestly it appears that other than the furnace fan there was not a lot of air circulating on the HRV itself. So possibly an HRV problem unrelated to the installation.
I am washing the filters on the HRV so wont be doing more HRV tonight. Next thing I want to see the LED on it and call Vanee.
PS. Is there a free / simple way to create wiring diagrams? Sorry for my crude description before.


Offline Porcupinepuffer

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Re: ecobee 4+ Furnace + AC + HRV
« Reply #6 on: July 09, 2018, 03:56:07 AM »
He did left a marrete on the floor... My wife was not impressed by him but he didn't check or have any recollection of what he did)

Unacceptable. Technician should be fired and only allowed to work at fast food restaurants.

Offline Garce

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Re: ecobee 4+ Furnace + AC + HRV
« Reply #7 on: July 09, 2018, 07:49:53 AM »
Well, maybe I go work at McD myself  :banghead:
My setup is working now and problem was me. I was not connecting the correct cables from Ecobee to the HRV.
Now, it is HRV B to Ecobee ACC+ and G to Ecobee ACC-
Just for the benefit of others: The original control was "simple touch"  - a one button control that cycle through
1. Light
2. Medium
3. Strong
4. Off
Now with Ecobee it is only Strong and Off. But you control how long it is on per hour.

Thanks everybody apologies for my clumsiness.