Wifi Thermostat

Tony Massi

I'm looking for a Wifi thermostat that uses only 2 low voltage wires to run a boiler on zone valves.
Most of the thermostats I have seen use three. I only have 2 wires running the thermostat.

ChrisJ

http://www.supplyhouse.com/Honeywell-YTHX9421R5127WW-Prestige-IAQ-Thermostat-Kit-w-RedLINK-Internet-Gateway

You won't need the two duct sensors, but the rest will work just fine.

Thermostat is powered via 2 wires, that don't even necessarily have to come from the boiler room, but can. For your app I'm assuming those two wires will connect the thermostat head to the EIM controller, which you will locate where convenient to run your new wires. For example, right by the zone valves.

They also sell a wireless outdoor sensor so the thermostat will show outdoor temp and humidity. It can use up to something like 6 indoor wireless sensors to average temp across multiple rooms, if you want, or just the single thermostat like normal.

This, in my opinion, is the best of the best when it comes to thermostats and all it needs is two wires.


Here's the outdoor wireless sensor.
http://www.supplyhouse.com/Honeywell-C7089R1013-RedLINK-Enabled-Wireless-Outdoor-Sensor

Tony Massi

Thanks for the response. I'm looking for a thermostat only in your opinion which one would you think would be best for this application.

ChrisJ

Tony Massi said:

Thanks for the response. I'm looking for a thermostat only in your opinion which one would you think would be best for this application.

That is only a thermostat, it's just split into a few pieces.

The "works" go in the basement, or wherever the equipment is. The head, goes where your thermostat is. No more clicking relays, no extra wires to run. The internet gateway goes where ever it's most convenient to plug into your internet and communicates with the rest wirelessly.

You don't need the outdoor sensor if you don't want it, and the two duct sensors that come with it don't need to be used, just throw them aside.


I know, it seems intimidating because it's in pieces, but it's not bad and it really is exactly what you're asking for. A good WIFI thermostat that only needs two wires. Though, it's internet connection will be hard wired.

it behaves very much like a Honeywell VisionPro. Very easy to use and you can customize the screen colors if you want.


Outside of this, I don't know of any other WIFI/Internet thermostat that doesn't need more than two wires.

ratio

What are you trying to control, two-wire zone valves? How many?

Tony Massi

Yes one V8043E zone valve

HVACNUT

@Tony Massi. The V8043E is a 4 wire ZV.
@ChrisJ. Just asking. Does an isolation relay need to be installed to close TT on the boiler? The end switch in the ZV wouldn't be used?
The wiring diagrams only show using the "U" dry contacts in a GEO, or accesories application, if I'm reading it right. Can the thermostat be programmed to close a set of U contacts on a heat call?

ratio

It sounds like the OP wants to replace an old heating-only snap stat with something WiFi enabled. If that's the case, a Honeywell 6320WF will give you programmability and WiFi. It does, however, require a common, a 3rd wire from the transformer that isn't always present with the older stats. A RedLINK 6320 can be run from batteries, however you will need additionally a RedLINK internet gateway to allow remote access to it.

Tony Massi

To make things easier I ran a new five wire thermostat wire to the old thermostat

ChrisJ

Tony Massi said:

To make things easier I ran a new five wire thermostat wire to the old thermostat

That works too.
Funny thing.............I replaced a 4 wire with a 7, but then that wasn't enough so I went to an 8, and then some how ended up with the Prestige that only needs 2.


The story of my life.

krimm

ecobee would have been nice but it runs on more than 2 wires. I like that it supports Alexa but it's too costly though, yayks!