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Ecobee4 and dual energy (Hydro-Quebec)

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  • Dec 23rd, 2021 7:53 pm
[OP]
Newbie
Feb 1, 2011
2 posts
Ottawa

Ecobee4 and dual energy (Hydro-Quebec)

Good day,

I bought an Ecobee4 to replace an Aube CT280-2HC1 with a TH146-n (see attachement).
The setup consist of a heat pump as the primary stage and gas as the secondary stage.
The 2 stages are controlled by a switch from Hydro-Quebec (from the meter): http://www.hydroquebec.com/data/residen ... gie-en.pdf
When it's warmer or equal to -12 degree the electricity rate is low and the heat pump is activated. When colder than -12 degrees then it switches to the high rate and the gas.
That switch from Hydro-Quebec is connected to the DE and CC of the Aube control module.
The Ecobee doesn't have such input. The Ecobee relies on the temperature on the Internet for the region. You can tell him to switch to the gas when it's -13 according to Internet but it will never be as accurate as the current setup and therefore a deal breaker for me unless I am missing something. Could I program an ACC input on the Ecobee and use it as a switch?
Also there is no input for the 2 temperature sensors currently connected to the Aube (outdoor and plenum) which are useful.

Thanks
Images
  • CT280-2HC1.jpg
8 replies
Newbie
Apr 6, 2006
40 posts
8 upvotes
Montreal
MathR601 wrote: Good day,

I bought an Ecobee4 to replace an Aube CT280-2HC1 with a TH146-n (see attachement).
The setup consist of a heat pump as the primary stage and gas as the secondary stage.
The 2 stages are controlled by a switch from Hydro-Quebec (from the meter): http://www.hydroquebec.com/data/residen ... gie-en.pdf
When it's warmer or equal to -12 degree the electricity rate is low and the heat pump is activated. When colder than -12 degrees then it switches to the high rate and the gas.
That switch from Hydro-Quebec is connected to the DE and CC of the Aube control module.
The Ecobee doesn't have such input. The Ecobee relies on the temperature on the Internet for the region. You can tell him to switch to the gas when it's -13 according to Internet but it will never be as accurate as the current setup and therefore a deal breaker for me unless I am missing something. Could I program an ACC input on the Ecobee and use it as a switch?
Also there is no input for the 2 temperature sensors currently connected to the Aube (outdoor and plenum) which are useful.

Thanks
Did you ever find a solution to this problem?
Member
Dec 21, 2020
448 posts
378 upvotes
mawio wrote: Did you ever find a solution to this problem?
Have you tried contacting Ecobee support? I mean they're there for a reason.
Deal Addict
Oct 19, 2020
1048 posts
667 upvotes
GTA
mawio wrote: Did you ever find a solution to this problem?
It should be doable with a external relay to divert signal to heatpump to the furnace instead and thermostat's internal lockout disabled, provided your setup provides a straight on/off signal to lock out the heatpump and doesn't rely on a sensor and controller.

The OP's setup uses a equipment interface module with a sensor.

The accessory terminal on ecobee is not for sensors, it is to control humidifiers, ventilation units, etc.

In general, it is better to use a setup with a sensor or signal from hydro-quebec than to rely on the internet for outdoor temperature. More accurate and reliable.

Would have to be a professional grade thermostat which is not cheap.

In the end I suggest that you check with a contractor familiar with dual energy and contact hydro-quebec to see what they accept. They may actually accept ecobee getting outdoor temp from the internet, set to lock out below -12c.
They definitely don't want heatpumps running below -12c as the whole point is to ease demand on the grid during extreme cold, they probably count on the reduced demand.
Hvac advice warning - inaccurate information on forum, vested interests in selling builder's equipment. Selling dealer-only brands without being authorized is a red flag. Report to CRA if offered no tax cash-deal. If it's 2 good to b tru, it is.
Newbie
Apr 6, 2006
40 posts
8 upvotes
Montreal
insertname2020 wrote: It should be doable with a external relay to divert signal to heatpump to the furnace instead and thermostat's internal lockout disabled, provided your setup provides a straight on/off signal to lock out the heatpump and doesn't rely on a sensor and controller.
This might be doable, I could use the Hydro signal as the input and flip a relay. The ecobee would report Stage 1 heating (heaptpump) while actually firing Stage 2 (gaz furnace).
I don't know if I have time for another project this month.. was hoping for an off the shelf solution.
Newbie
Apr 6, 2006
40 posts
8 upvotes
Montreal
insertname2020 wrote: In the end I suggest that you check with a contractor familiar with dual energy and contact hydro-quebec to see what they accept. They may actually accept ecobee getting outdoor temp from the internet, set to lock out below -12c.
They definitely don't want heatpumps running below -12c as the whole point is to ease demand on the grid during extreme cold, they probably count on the reduced demand.
I already have rate DT with Oil, this is just a replacement system using natural gaz. Technically Hydro doesn't need to be involved.
My contractor is fine with using an ecobee and setting the lockout to -10c, I was just curious about getting a more accurate (and local) reading.
I already have a tool for getting a soft-notification for my Hydro Quebec rate switch.. but I don't know how to send a soft local signal to the ecobee via an API to stop engaging the heatpump (something like "switch to aux heat") ..
Deal Addict
Oct 19, 2020
1048 posts
667 upvotes
GTA
mawio wrote: I already have rate DT with Oil, this is just a replacement system using natural gaz. Technically Hydro doesn't need to be involved.
My contractor is fine with using an ecobee and setting the lockout to -10c, I was just curious about getting a more accurate (and local) reading.
I already have a tool for getting a soft-notification for my Hydro Quebec rate switch.. but I don't know how to send a soft local signal to the ecobee via an API to stop engaging the heatpump (something like "switch to aux heat") ..

Ya, ecobee can not be used with any outdoor sensor at this time - it is really a feature they should add.
Doubt they have anything special to work with hydro-quebec and actually lock out hp.



Other high end thermostats* can use a local sensor - though I wouldn't bother replacing a working ecobee for that.

*Example: Honeywell vision pro wifi if you use a wired sensor, honeywell vision pro with redlink for wireless outdoor sensor but needs a separate wifi gateway if you insist on wifi.
Hvac advice warning - inaccurate information on forum, vested interests in selling builder's equipment. Selling dealer-only brands without being authorized is a red flag. Report to CRA if offered no tax cash-deal. If it's 2 good to b tru, it is.
Jr. Member
Apr 30, 2007
140 posts
37 upvotes
Montreal
Exact same question / issue here. I’m in Quebec and have a dual energy setup (electric and gas). Replaced a Honeywell (?) thermostat with an Ecobee4 and just realized today after seeing the red light for < -12C outside that the ecobee probably isn’t doing the switch to natural gas cuz it doesn’t know to? How do you “set the lockout” at a certain outdoor temp based on internet temperature? I don’t see that setting in my ecobee anywhere.
Newbie
Dec 22, 2021
1 posts
There’s wires coming from the meter 2 are for a led to indicate inside your house it’s on and other 3 are dry contacts from a relay built in meter. It will take the “Y” wire (heat pump) and change it to Aux to get energised. So oil/gas comes on under -12. Just did all this last weekend. My old Aube stat. indicated with a small light on display DT is on.

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