Ecobee 5 + Lifebreath HRV installation help

Started by econewbee, September 18, 2019, 08:04:35 PM

Previous topic - Next topic

econewbee

I have an Ecobee 5 (SmartThermostat with voice control) that I'd like to use to also control a Lifebreath HRV. I'm having trouble understanding what to connect to the ACC+/- terminals.

According to Ecobee's site, it looks like I need to connect it to the R and G wires of the HRV controller.
https://support.ecobee.com/hc/en-us/articles/360010158091-SmartThermostat-with-voice-control-and-ecobee4-Wiring-Diagrams



However, I have a Lifebreath BC-02 controller and it appears to have 3 wires (R, G, and Y).



(Not sure if it matters, but the HRV Terminal Block seems to be interlocked with the furnace as well, via the COM, NO, and NC terminals)

So do I just remove the R & G wires from the Lifebreath wall controller and connect them to the ACC- and ACC+ ports on the Ecobee thermostat? If so, what do I do with the remaining Y wire?

I also read that it might not be so simple, and might require connecting the ecobee to the HRV terminal block as a "dry contact" and needing to put a jumper cable between 2(ON) and 3(RED) and then connecting the ACC+/- terminals to 2(ON) and either 1(LOW) or 6(HI).

Can anyone help with this?

(Also, I'm unsure if I will be losing functionality by doing it this way. Would I be better off leaving the original Lifebreath controller in tact and not bothering with connecting the Ecobee to the HRV?)

Thanks in advance!

Admin

You can eliminate the interlock wiring as the Ecobee will control the furnace fan when the HRV starts.

See the attached picture.  Install the jumper between ON and RED.  Then wire the Ecobee ACC wires to HI and ON.  The HRV will run in high speed when it's turned on.  You could also use low speed instead.  Just connect the ACC wire to LOW instead of HI.  The Ecobee can only control one speed and not both.

econewbee

Thanks for this! Also, not sure if it matters, but I have a dual zone system (one furnace, 2 zoned areas controlled via dampers). Some more questions if you don't mine:

1. Is it okay or safe to keep the interlock wiring (ie. keep the wires coming out of COM/NO/NC on the HRV terminal block) as is, or  does it need to be removed in order for this configuration to work?

2. Does this mean i can't just disconnect 2 wires from the Lifebreath controller and connect them to the Ecobee ACC terminals? If so, does this mean I should ensure that all the controller connections to the HRV terminal block are removed as well (ie. RED/YEL/GRN which currently go from the terminal block to the controller)

3. When connecting the Ecobee ACC wires to HI and ON (and also putting the jumper between ON and RED), which one does the ACC- connect to and which one does the ACC+ connect to? Or are they interchangeable?

4. I'm okay with choosing a single fan speed (either HI or LOW), but the current Lifebreath controller (BC-02) https://www.lifebreath.com/product/controls-and-timers-basic-wall-control/ also has dehumidistat controls. Would I be giving this feature up if I choose to use the Ecobee instead?
(If so, just debating whether it would be better and simpler to keep the lifebreath controller and connect the Ecobee stats without the ACC connections)

Thank you so much for your help!

Admin

Quote1. Is it okay or safe to keep the interlock wiring (ie. keep the wires coming out of COM/NO/NC on the HRV terminal block) as is, or  does it need to be removed in order for this configuration to work?

Leaving the interlock wiring connected should be no problem, and will come in handy should you ever replace the Ecobee with a model that again requires this interlock wire.  Basically the furnace fan will start anytime the HRV starts.  Both the interlock wiring and Ecobee do this, but don't conflict with each other.

Quote2. Does this mean i can't just disconnect 2 wires from the Lifebreath controller and connect them to the Ecobee ACC terminals? If so, does this mean I should ensure that all the controller connections to the HRV terminal block are removed as well (ie. RED/YEL/GRN which currently go from the terminal block to the controller)

Yes, wire exactly as shown in my picture and remove all other wiring.

Quote3. When connecting the Ecobee ACC wires to HI and ON (and also putting the jumper between ON and RED), which one does the ACC- connect to and which one does the ACC+ connect to? Or are they interchangeable?

They are interchangeable.  It doesn't matter which ACC wire connects to HI or ON.

econewbee

Thanks for your help! I think I got it now... just to be clear this is the diagram I have of the current setup, and the proposed setup.

I guess the only thing to figure out is whether it's okay to keep the COM/NC/NO wires attached or to remove them entirely.


Admin

Yes, it looks good.  Both the Ecobee and HRV steal 24V from the furnace so I don't think it would be a problem if you left the interlock wiring and both the HRV and Ecobee energized the furnace fan, but I would still disconnect it to be safe.  The Ecobee will control the fan now.  Leave the wiring there in case you ever need to reconnect it.

econewbee

Just wanted to follow up on this... I wired everything up (as posted above) but now I've been noticing this behaviour:

The fan/HRV seem to almost constantly be running whenever I am home. Is this normal/expected behaviour, or does this mean I wired something incorrectly?



Admin

I would look over the Ecobee HRV settings again.  I seem to remember there being some HOME and AWAY settings.  There's a dehumidification setting under SYSTEM, HRV, DEHUMIDIFY IN WINTER.  Make sure it's disabled or it may be running until the humidity lowers.

kebel87

Quote from: econewbee on September 19, 2019, 07:48:25 AM
4. I'm okay with choosing a single fan speed (either HI or LOW), but the current Lifebreath controller (BC-02) https://www.lifebreath.com/product/controls-and-timers-basic-wall-control/ also has dehumidistat controls. Would I be giving this feature up if I choose to use the Ecobee instead?
(If so, just debating whether it would be better and simpler to keep the lifebreath controller and connect the Ecobee stats without the ACC connections)

I'm in the same situation as you were (except my HVAC and HRV are not interlocked).

1. Did you end up getting/finding the answer to this question? Did you loose the dehumidstat feature?

2. What did you end up doing with your third and unused(?) wire?

3. It's been 4-5 months since you installed Ecobee and plugged your HRV to it. Would you recommend it to someone who's on the fence wether to proceed or not?

4. I also have controllers in both bathrooms. My understanding is that I leave them connected as they were. Is that what you did? Strangely, they do have 3 wires too...

Thanks!

Admin

There HRV exchanges air.  There is no real dehumidification unless the outdoor humidity is lower than indoor humidity.  The HRV doesn't work any differently running on dehumidification mode versus on.  Only the fan speeds change and that is the only feature you lose with the Ecobee.  You can use high speed or low speed but not both.  The third unused wire powers the LED lights on the HRV controller and is not required when using the Ecobee.

You would have to leave the bathroom timers connected.

jz6pwc

After following these directions my terminal block has a flashing red light.  What does that mean.  Everything else seems to be functioning...

Admin

What else do you have connected to the HRV?

A flash every 8 seconds is likely just normal standby mode.

My HRV is wired this way and flashes every 8 seconds when it's not running.  I use high speed instead of low speed though.

jz6pwc

Thanks for the quick reply.  Yes, it does blink every 8 seconds.  I couldn't find the meaning of that anywhere.  How do you know its just in standby?  Did I miss something in the manual?

Also, to answer your question, I have the furnace connected.  That's it.  (other than the ecobee)  I used the wiring diagram in the post.

Admin

I couldn't find any mention of it in the manual, but it must be standby as mine is working fine as well.

And sorry, I realize now those other wires are for the interlock and can left.