Wi-Fi Thermostat without C Wire

[Reicherb]

I'm looking to replace 3 thermostats on my hydronic heat system. I don't have a C wire and adding one will be impossible in 2 of the 3 thermostat locations. Can anyone recommend a thermostat for my application?

Thanks!

 

[Bannerman]

Inclusion of a Wifi radio substantially increases the amount of power the thermostat will consume compared to a typical non-wifi programmable thermostat that will often be powered by a replaceable battery.

You didn't state how many wires lead to each thermostat.

Ecobee include a Power Extender Kit (PEK) device with each thermostat, but at least 4-wires will be required between each PEK and its corresponding thermostat.

Honeywell offer a similar C-wire adaptor as an accessory, but the list of included items does not specify an adaptor being included with Honeywell smart thermostats.

Google Nest offer a 2-wire adaptor that also does not appear to be included, but it seems to offer less functionality compared to the 4-wire alternatives.

Ecobee PEK description

Honeywell Adaptor

Nest adaptor

 

[Sponsor]

 

[Reicherb]

Inclusion of a Wifi radio substantially increases the amount of power the thermostat will consume compared to a typical non-wifi programmable thermostat that will often be powered by a replaceable battery.

You didn't state how many wires lead to each thermostat.

Ecobee include a Power Extender Kit (PEK) device with each thermostat, but at least 4-wires will be required between each PEK and its corresponding thermostat.

Honeywell offer a similar C-wire adaptor as an accessory, but the list of included items does not specify an adaptor being included with Honeywell smart thermostats.

Google Nest offer a 2-wire adaptor that also does not appear to be included, but it seems to offer less functionality compared to the 4-wire alternatives.

Ecobee PEK description

Honeywell Adaptor

Nest adaptor

I have 3 wires to each thermostat. Unfortunately there isn't an unused wire available. Does that mean none of the solutions you suggested will work? Maybe the nest one works. I can't seem to follow how it works.

 

[Fitter30]

What are the three wires and do they go to a zone or pump control and what is it?. Haven looked yet to see if there is a wireless stat run off wifi.

 

[Reicherb]

There are 3 wires. R, W, Y

Thanks.

 

[Fitter30]

There are 3 wires. R, W, Y

Thanks.

Where to they go. Heat is usually R to W turns on the heat but Y might be used to power a valve close. Take a few pics of the boiler piping and if there's controls on the wall.

 

[Reicherb]

Oops sorry. They go to zone valves.

Pictures to come.

 

[Reicherb]

Here are some pictures. Hopefully helpful... I found some that I look a few years ago. I'm not currently near home.

 

[Fitter30]

The green wire twisted around the wire at the zone valve does that go up to the stat? Brand and numbers off zone valve?

 

[WorthFlorida]

Most thermostat wire cable were usually at least four wires. Don' necessary go by the colors.

Another option is a c-wire adapter. just google it. It's a transformer you plug in an outlet near the thermostat, however, a wire to the thermostat is exposed. You can run the thin wire along the base molding, drill a small hole in the wall cavity the thermostat is mounted. Snake the wire in side the to the t thermostat.

A third option is Honeywell/ WiFi thermostats that can be used with remote sensor. Mount three thermostats near the zone controller. Program so only the remote sensor are only used for temperature control. Mount the remotes anywhere or at the thermosta. Use your smartphone to view the temperature and change the settings.

 

[Reicherb]

The thermostat wires are 3 conductor. I used wire with more conductors between the zone valves and the boiler. That's what you see wrapped. It's a multiple story house. There is not an easy way to replace the wires or I would have already done that.

Zone valves are white Rodgers. There are 3 of them. 1 on each floor of the house.

 

[WorthFlorida]

The thermostat wires are 3 conductor. I used wire with more conductors between the zone valves and the boiler. That's what you see wrapped. It's a multiple story house. There is not an easy way to replace the wires or I would have already done that.

Zone valves are white Rodgers. There are 3 of them. 1 on each floor of the house.

You have a very nice boiler room. The work looks great. It seems the best bet is two C-wire Adapters for the second and third floors. First floor a new thermostat cable can be had.

 

[Reicherb]

You have a very nice boiler room. The work looks great.

Thank you. I actually did the work myself with some guidance from the forums.

Are you able to explain how the C Wire adapters work? I've read a couple of installation guides and don't understand. Do the existing wires become low volt communication wires rather than just delivering power?

 

[Fitter30]

Disconnect Y wire at thermostat. According to the install instructions valve only needs two. See if a call for heat then satisfied strokes the valve both ways.

 

[Jeff H Young]

I does look neat!

 

[Reicherb]

Disconnect Y wire at thermostat. According to the install instructions valve only needs two. See if a call for heat then satisfied strokes the valve both ways.

I'll give it a try. My time at home is limited as I currently have a sick kid.

 

[WorthFlorida]

Thank you. I actually did the work myself with some guidance from the forums.

Are you able to explain how the C Wire adapters work? I've read a couple of installation guides and don't understand. Do the existing wires become low volt communication wires rather than just delivering power?

It'll take me a day or two. It's a busy week, chemo therapy, cancer support group session, An appointment on Thursday morning. Today at my church, I help the maintenance guy Billy rewiring for the church sign. The 40 year old outlet was all corroded. Added a photo cell, a cutoff switch and new GFCI outlet and three new boxes. I was there from about 8:30 to 6pm. There was a cold breeze from the north all day long. 46º at 8:00 am, didn't get above 65º. Very cold for Central Florida. Thank for asking my help. I'll get to it.

 

[Fitter30]

It'll take me a day or two. It's a busy week, chemo therapy, cancer support group session, An appointment on Thursday morning. Today at my church, I help the maintenance guy Billy rewiring for the church sign. The 40 year old outlet was all corroded. Added a photo cell, a cutoff switch and new GFCI outlet and three new boxes. I was there from about 8:30 to 6pm. There was a cold breeze from the north all day long. 46º at 8:00 am, didn't get above 65º. Very cold for Central Florida. Thank for asking my help. I'll get to it.

Take care of yourself work is always there. He's got a sick kid Post 16 might have a fix for him post 14

 

[WorthFlorida]

Take care of yourself work is always there. He's got a sick kid Post 16 might have a fix for him post 14

What does the post mean?

 

[GReynolds929]

What does the post mean?

The number of the reply post. Yours is #19, this one is #20.