Rush decision on thermostat, recommendations?

Hardware
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My current (dumb) HVAC/climate thermostat appears to have malfunctioned, and I’ve called for an HVAC service check today. I had planned on replacing it anyway before this summer, though now need to make a decision quick (likely today).

My current HVAC system is a 2 stage heat pump and a 2 stage gas furnace (in heating cycle, the heat pump works down to 37F (2.8C)). I have a strong preference for local HA control, though not absolutely mandatory.

Over the last year or two, I’ve been loosely tracking Ecobee, though not in any detail. Am now seeing recent issues with the Homekit integration.

If you have one of the HA integrated thermostats that can work with 2 stage heat pumps and furnaces, do you have a recommendation or review of said thermostat and HA integration?

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I’ve seen lots of opinions on here. I will only offer that my Honeywell “smart” thermostats have been 100% reliable. They integrate nicely with HA, but work fine on their own if HA were to fail. My biggest issue with them is that the integration is cloud-based, but it’s been reliable and the Honeywell app provides a good backup if HA fails while I’m away.

This isn’t so much a recommendation as a data point for you to consider. I’m sure there are other thermostats out there which are just as good.

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Ecobee has been my thermostat for years. Easy to use and easy to define range limits. Their phone apps are nearly 100% identical to the actual device.

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I got the ecobee smart thermostat with voice (I do not use the voice). I ordered through my Utility provider for just 75.00 plus tax and shipping. I did have to change out my wire (from 4 conductors to 7 conductors), so I could eliminated the dongle. Depending on your installation that maybe fisible also. I had no issues with the ecobee HA integration either. Plus I use the ecobee web portal to access the data till I get a chance to figure out how to store the data using HA and process it on my own (to stop using the portal)

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The HVAC technician came by, though could not replicate the error condition when it was 44F (6.7C) outside, perhaps because the error occurred in sub-freezing conditions. Additionally, I found out the interface of my Goodman HVAC system motherboard has a proprietary communicating protocol, using R, C, 1, and 2 (not L1 and L2). The HVAC motherboard also has sockets for G, W1, W2, Y1, Y2, and O (see below), though they would require a different plug, and I have no idea if the firmware on the chip currently supports those connections. The HVAC system has a 2 stage heat pump and a 2 (or 3?) stage gas furnace.

HVAC system motherboard interface

HVACMotherboardInterfaces
HVACMotherboardInterfaces1323×678 439 KB

Thermostat mounting plate

ThermostatBackingPlate
ThermostatBackingPlate1920×864 59.6 KB

So I contacted Ecobee technical support, and after significant back and forth of photos/etc, their analysis concluded that I would have to call out a competent HVAC technician who could set up the correct plug wiring, and snake the new wire bundle through the walls to a new Ecobee thermostat, and there would be a good chance it would work.

So with that estimation, and the fact that the thermostat is not having errors currently (I just tried it now the following morning when freezing outside and the reboot appears to have cleared away the previous issue), I do not plan to take the chance with a rewiring, so will for now abandon the objective of having an HA-controllable HVAC system, at least until I can set aside time to sufficiently and thoroughly analyze the alternatives.

I can, however, monitor both the blower and the heat pump electrical power consumption via my IoTaWatt, so that will have to suffice for now.

Thank you @CaptTom , @FredTheFrog , and @lordwizzard for your input!

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Have a look at installing and using InfluxDB with HA. Then you could use Grafana for graphical output. With InfluxDB you can store all data HA gets and in Grafana you can display them in graphs and so on.

Everything Smart Home has a good video how to install and use it.

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@Loeffel , I’m running HA on an RPi 4 8MB. Am running a Z-Wave network, Wifi components, Energy Management, ESPHome, HACS, etc. Does my RPi have enough bandwidth for an Influx/Grafana combo?

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I had it running on RPi 4 with 8GB without problems. I just switched to another system because I needed to run something additional on the system and that wasn’t available for HA OS.

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So to recap my findings, my current White-Rodgers thermostat and Goodman HVAC system have a proprietary “communicating” interface that Ecobee does not currently support, though their tech believes my interface may be able to be adjusted to work through the use of different plugs and wiring harness, though it is not clear the firmware version on the HVAC motherboard handles the currently unused interface points (W1, W2, Y1, Y2, G, O).

Even if the Ecobee could be made to work, their tech said it may not be able to control the stages on both my heat pump and my furnace, which means my high efficiency HVAC system would quite likely become much less efficient (which would defeat my reason for getting an Ecobee thermostat, as I target very low energy use through my home).

Ecobee does have solutions for most of the major brands that are out there, though, including support for multi-stage heating and cooling. Please see this compatibility guide before you buy if you are considering Ecobee;

https://support.ecobee.com/s/articles/What-types-of-HVAC-systems-are-ecobee-thermostats-compatible-with

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