I am forced to get a new furnace (heat exchanger is cracked) and AC due to age (19 years old). I have an Ecobee 3 thermostat with 3 external sensors which works well but new HVAC is 2-stage heat and cool with variable speed fan. Ecobee 3 should support the 2 heat/cool but Ecobee explicitly states that the 3 tstat does not support multi speed fan. Quick web search revealed that Ecobee 3 Lite tstat should now support external sensors and multi speed fan.
Can anyone confirm that Ecobee 3 Lite does indeed work correctly for modern HVAC (Lenox) 2 heat/2 cool with variable speed fan and integrate well with Hubitat?
Also the service company says this Lenox must be sold with a Honeywell Lyric T6 thermostat. Standard Lyric T6 does not appear to be a “smart” model. There is another Lyric T6 available for $100 more with WiFi but users give it only 2 stars and report lots of issues staying connected to Honeywell Home app/site.
I thought about the Honeywell T6 Z-wave but am concerned that its internal technology is dated which may cause future issues with latest furnace/AC technology. Any thoughts?
That's not entirely correct. As long as the furnace/air-handler retains the smarts to control blower speed, it will do so. All the ecobee sends is an on/off signal. BTW, the ecobee3 Lite works in exactly the same way.
I used an original ecobee3 with a Lennox variable speed furnace and a Lennox 2-stage heat-pump for a couple of years, and it worked fine.
What exactly do you mean? It is the same technology that is in the Honeywell Lyric T6 thermostat that your dealer recommends.
With that said, I find the Honeywell T6 to be a God-awful thermostat to use with Lennox 2-stage equipment. Staging control is horrible - it is based on cycles per hour rather than a temperature delta, which is how ecobee does it.
If I were you, I'd stick with the ecobee. If you need a Z-Wave thermostat that works well with a 2-stage outdoor unit and a variable-speed furnace, I'd recommend the GoControl. I have been using it for almost 2 years now with no issues.
New Lennox furnace/AC installed and appears to be working correctly with Ecobee 3 thermostat. The weather has been mild since Monday installation so have not seen the Stage 2 used yet.
Our weather (deep South) is always mild. It is in the low 50s today, and my Lennox has also only run in Stage 1. It pulls about 3400-3500 watts while running in Stage 1, and about 800-1000 watts more in Stage 2. That wattage calculation includes the air-handler, outdoor unit, and an in-duct blower that comes on only during heating and cooling.
New furnace is doing great with Ecobee thermostat. New system is much quieter than previous. Hardly know its running. We just started having colder weather the last 2 days and Ecobee is tracking use as before. Thanks for your advice.
