Looking for a modern 2 wire thermostat
#1
Member
Thread Starter

I bought an ecobee 3 lite knowing it needed an adapter for a 2-wire system. It turns out that's not enough.
After waiting 2 days for a response, they told me that their product is incompatible w/our Honeywell 2-wire zone valves and that we should replace them. Yeah - I'm doing that for them.
I don't want to use old time thermostats and my wife likes the sleek looks of thermostats w/screens, but I'm not overhauling my system just for that.
Anyone know of a modern type thermostat that will work on a 2-wire system, that is not dependent on WiFi or connecting to the manufacturer's web site to run? Nest is a no-go.
Thanks guys!
After waiting 2 days for a response, they told me that their product is incompatible w/our Honeywell 2-wire zone valves and that we should replace them. Yeah - I'm doing that for them.
I don't want to use old time thermostats and my wife likes the sleek looks of thermostats w/screens, but I'm not overhauling my system just for that.
Anyone know of a modern type thermostat that will work on a 2-wire system, that is not dependent on WiFi or connecting to the manufacturer's web site to run? Nest is a no-go.
Thanks guys!
#2
Are you looking for a WiFi enable Tstat or just a 2 wire programmable style, you may want to remove your old Tstat to see how many wires are actually in the cable or check the cable from the Tstat at the boiler.
Geo
Geo
#3
Member
Thread Starter
It's a complete 2-wire system to all 3 zones - I wired it years ago.
Looking for a contemporary 2-wire programmable - no WiFi. ecobee is it except for the 2-wire BS they gave me.
Looking for a contemporary 2-wire programmable - no WiFi. ecobee is it except for the 2-wire BS they gave me.
#4
Member
Anything battery operated should work. For contemporary/modern do you mean LCD touch screen?
You should be able to use Ecobee with only two wires using a common maker - https://www.fast-stat.net/pdf/Common...ctions-Set.pdf
You should be able to use Ecobee with only two wires using a common maker - https://www.fast-stat.net/pdf/Common...ctions-Set.pdf
#6
Member
Thread Starter
According to ecobee "Your zone valves arent compatible. If you're wiring the thermostats directly to the zone valves youll need to get compatible Zone Valves that take an R, W and C wires."
#7
Member
Thread Starter
@Houston204 The Honeywell Redlink TH8110R needs a module and that is either wireless or WiFi.
Last edited by syakoban; 01-25-18 at 01:23 PM.
#8
While it supports a module and many other products it is not required. I have installed many with no module.
I had one on my house with no module for years.
I had one on my house with no module for years.
#9
Member
Thread Starter
@Houston204 That's what I'm after but in the installation instructions, it indicates a 2 wire install needs the equipment interface module. No?
https://customer.honeywell.com/resou...0s/69-2760.pdf
https://customer.honeywell.com/resou...0s/69-2760.pdf
#10
It is the top picture.
I have installed a bunch of those thermostats but have only connected a few of that model to an equipment interface module.
The module gives you the option of using this as a wireless thermostat.
The module also gives you the ability to control a 3 stage heat / 2 stage cool heat pump and a dehumidifier and a humidifier and a fresh air damper using only 2 wires at the stat.
The top picture states that C is optional with batteries.
Install the supplied batteries and connect the white wire to W and the red wire to R.
Easy Peasy.
I remember when I started in this field in the early 90's we serviced a lot of WWII veterans. Many of them liked to use that term.
I have installed a bunch of those thermostats but have only connected a few of that model to an equipment interface module.
The module gives you the option of using this as a wireless thermostat.
The module also gives you the ability to control a 3 stage heat / 2 stage cool heat pump and a dehumidifier and a humidifier and a fresh air damper using only 2 wires at the stat.
The top picture states that C is optional with batteries.
Install the supplied batteries and connect the white wire to W and the red wire to R.
Easy Peasy.
I remember when I started in this field in the early 90's we serviced a lot of WWII veterans. Many of them liked to use that term.
#11
Member
Thread Starter
Thanks Houston204. I guess I'm slow, but may have it now - the batteries are a substitute for the C wire, just as I have batteries in my existing Honeywell thermostats. Correct?
Also, we have three heat zones and one A/C zone. So on one thermostat we'll be tying in the A/C. No issues there?
Also, we have three heat zones and one A/C zone. So on one thermostat we'll be tying in the A/C. No issues there?
#12
There will be no issue with it as long as you remember to remove the jumper between R and RC.
Heat will still be R and W.
The cooling will be RC, Y and G.
Heat will still be R and W.
The cooling will be RC, Y and G.