I’ve seen a lot of guessing on the forums but I seemed to have gotten a definitive answer, abet I had to dig into the details. After quite a few go arounds with Wyze support as to the algorithms used in heat pumps and specifically geothermal I got this response. I bolded the relevant passages:
Thanks for following up on this issue and apologies for the inconvenience this issue had caused you. I have raised your question to the team for further checking. Allow me to explain further.
I got an update from them that the Wyze thermostat does not distinguish between Air Source Heat Pumps and Geothermal Heat Pumps. The outdoor weather is used to determine when to run only the Aux heat in both cases. However, there are other factors that determine when to run both Aux heat and heat pump.
- When the temperature difference between setpoint and room temperature is greater than 4 F
- When the heat pump has been running longer than the default runtime (determined by Behavior settings - eg: max savings, balanced, max comfort, etc)
In summary, Geothermal Heat Pumps are compatible with the Wyze Thermostat but are treated in the same way as Air Source Heat Pumps.
I hope that answers your questions. Should you have further questions, feel free to let us know.
Jennifer | Wyze Wizard
This is good info with regards to the algorithm, but also discloses the Wyze is NOT compatible with GeoThermal heat pumps. Yes, it will control them, but the bill will skyrocket needlessly in the winter. A geothermal heat pump doesn’t work against the outside air as a standard heat pump, but against the earth’s temperature. So going to AUX heat based on ‘outdoor weather’ will needlessly increase the electrical bill on a geothermal unit.
This seems a easy fix, As the unit doesn’t have a outdoor air temp sensor, one would guess it gets the temp for your location from the internet. Wyze should either ignore the outdoor temp for geothermal or just set up a zip code on the equator.
Does anyone have access to the tech team or programmers? I’d really like to stay with Wyze as I need the indoor sensors.
I do, I can definitely get this to them but I can’t guarantee that any fix would come quickly as we have limited resources currently.
Thank you! I’d first like a definitive answer as to the present logic, as have others said, there is no physical outdoor sensors so we all are only guessing internet weather for the claim it uses outdoor temperature.
Maybe you could ask them first how the themorstate behaves for a heat pump, both air and geothermal?
I will see if I can at least get that for you.
Thank you so much. If as it being claimed by support, that the Wyze is triggering AUX heat via internet weather, then the product SHOULD NOT be marketed as GeoThermal compatible, since Geothermals reference ground and not air temp. The good news here is this should be an easy fix, just a toggle for the type of heat pump and to ignore internet weather as a factor for AUX heat.
ok, I just got this from support, so it does in fact appear the thermostat is NOT geothermal compatible, as it turns on aux heat (only) <35F based on a weather API reference outdoor air temperature, which is irrelevant for a geothermal system and will in fact cause a massive electrical bill
I’m an IoT firmware programmer and the fix for this is simple. Just a toggle of flag to use the weather API or not to trigger AUX heat (a switch for standard heat pump vs geothermal)>
As you are currently marketing the product as GeoThermal compatible (it isn’t) I hope that can raise the priority of the fix. Happy to wait a few weeks as I’m a Wyze household, otherwise I’ll need some RMA’s for returns. Thankfully haven’t installed it yet.
The Wyze Thermostat has built-in temperature and humidity sensors that are already well-calibrated at the factory, and it uses weather API to determine outdoor temperature. This is why it knows the outdoor temperature even though there is no outdoor sensor available.
The information in the previous email came from the team we are working with about the Wyze Thermostat. They informed us that geothermal heat pumps are compatible but since the Wyze Thermostat cannot distinguish between air-source heat pumps and geothermal heat pumps, geothermal heat pumps are being treated the same way as an air-source heat pumps.
As for your question in a separate email, if the Wyze Thermostat takes into consideration the outdoor temperature in triggering aux heat, the answer is yes. The outdoor weather is used to determine when to run only the Aux heat (that is when the outdoor temperature falls below 35 F). That cannot be disabled as that is pre-programmed to the Wyze Thermostat.
I trust that I was able to explain things further. If you have additional questions, please do not hesitate to let us know. Have a great weekend!
All the best,
Jennifer | Wyze Wizard
As a wrap-up here, here is my last exchange with Wyze. Disappointing. I had hope to keep my home entirely ‘Wyze’ but it seems that isn’t possible. Not turning my back on their new products but it won’t be a thermostat. The good news is the return process seemed to be seamless and my refund already posted.
Thank you. I’ve returned all your units and purchased EcoBee, which works properly with GeoThermal systems. But just to be clear, you should stop claiming the thermostat is GeoThermal compatible. To make that claim, at a minimum you’d need to ignore outdoor temperature. It’s a simple fix and it’s a shame you are unwilling to consider it.
On Fri, Feb 3, 2023 at 12:25 PM Support <email@example.com> wrote:
##- Please type your reply above this line -##
Your ticket (27xxxx) has been updated. To add additional comments, please reply to this email.
Feb 3, 2023, 9:25 AM PST
Thanks for the update and I truly apologize for the delay in getting back to you. I’ll be sure to look into this further.
I have made a follow-up with the team about your question and I’ve confirmed that there is no way to disable the outdoor temperature sensor.
The Wyze Thermostat is designed for the most typical systems and should be compatible in most cases unless it is a system that simply isn’t compatible. Our compatibility checker can tell if it is compatible based on your thermostat wirings or the terminal labels you will select on the wire selection page.
While we understand that there are some systems that can pass the compatibility checker but work differently than what your system usually does, we can say that that system is not compatible, especially if using the Wyze Thermostat to that system will cause issues in the long run.
I understand that it will be inconvenient if the Wyze Thermostat’s outside temperature sensor cannot be disabled. As much as we want to, we don’t have a way to have that feature disabled. Also, the Wyze Thermostat can only support one of the four accessories: emergency heat, humidifier, dehumidifier, and ventilator, which can be connected to the * terminal. It doesn’t support ground temperature sensors.
I would like to sincerely apologize if you felt disappointed and I trust that I have answered your questions. Regardless, as one of the leaders here at Wyze, I would like to say thank you for working with us on our troubleshooting and for your patience in getting the answers that you need.
Please feel free to let us know if there is anything else I can assist you with. Have a great weekend!
All the best,
Jennifer Wyze Wizard
This is an interesting choice in wording by Wyze since the Thermostat has no S, S1, or S2 Outdoor Temp Sensor connection capability or compatibility.
More specifically, they should have stated that the thermostat has no way of disabling the Local Outdoor Temperature data received via the internet and subsequent internal Outdoor Temp logic.
But, thank you for being so diligent in your inquiry. It has revealed significant new details about how the thermostat operates (or more correctly, doesn’t operate).
Best of luck to you with the Ecobee!