Thermastats with only two wires

(Larry) #1

I have a bunch of thermostats with only two wires that control multiple zones for in floor heating… anyone know of any replacement thermastats that can do this… there are no extra wires behind to run and I don’t want to start rewiring them all… battery power is ok… thanks

(Brian) #2

What’s the brand name and model number? Start there. Most of these setups are proprietary, and you have to replace both boxes at the end of the wires, can’t just chuck a Nest or Ecobee on there. Won’t talk to the other box.

(Larry) #3

cant replace it on the furnace end it is a huge box that has wires running to all the zones… the zones are cheaper green/white Honeywell thermostats… with only two wires and batteries… I am not at the house now. it is remote.

(Ron S) #4

The one which has worked pretty well for us are the CT-100’s. They don’t require a common. Those are z-wave devices. I personally use two of these for heating. They run on 4 batteries and currently at 40% from last winter. Just search the community for CT100.

(Larry) #5

thanks a million will do

(Fast, Good, Cheap...pick two.) #6

The “box” has to be eliminated and wires run straight to the T-stat.

My HVAC was not zoned but it did have this setup. II was lucky in that all needed wires were run just not connected.

(Ron S) #7

You can as such power the common thru the lockstate connect adapter and now you have a zwave repeater. :smile: it comes with two wires. One goes to common and one to the R on CT100 (so, two wires on Rh connector)

Warning: Do not set your house on fire though or get electrocuted. :wink:

(Brian) #8

I may have been wrong, the two wires can be really old simple ones too.

(Ron S) #9

I replaced my vintage thermostats with CT100’s for 2 zone heating.

(Unni) #10

See the CT100 manual here. Page 5 talks about a two wire system. Don’t know if that’s what you have. If you don’t have C wire, it will run on battery.

(Larry) #11

yes that is what I have… just two wires with thermostats running off battery … thing the ct 100 is best solution… Honeywell has zwave one but it requires the wire add on kit… and I don’t even know where the C wire is in that large box… As I said it is in floor heating with 4 zones… each with its own thermostat.

(Joseph Fattizzi) #12

I have what they call line volt hearing. It’s baseboard hearing with an oil furnace. Just for heat.

Can I use this?

(Larry) #13

I would check with multimeter needs to be 24v I believe

(Ray) #14

Did you mean to say line voltage heating? If that’s the case then no. Those thermostats are for low voltage system. There are a couple of companies releasing baseboard thermostat pretty soon.