I am having issues wiring my Evolve T100R Thermostat to my furnace. My furnace is gas.
Basically on the old Thermostat, I have 2 wires (Red goes to R & Rc, the white wire goes to W). I know that on the Evolve Thermostat, I have to wire in 3 wires (one at C, another at RH and the other at W1). I am assuming that I need to wire the Red to RH and the White to W1…C is unsure at this point. I can easily run another wire from my thermostat to my furnace for this 3rd wire that is needed. My question is, where do I connect this 3rd wire…or do I need to rewire something at the furnace end to make this work?
I have attached 2 pictures, one showing the furnace wiring diagram, the other shows where the red and white wires are physically connected to the furnace.
[quote=“pbrisebois, post:1, topic:181361”]I am having issues wiring my Evolve T100R Thermostat to my furnace. My furnace is gas.
Basically on the old Thermostat, I have 2 wires (Red goes to R & Rc, the white wire goes to W). I know that on the Evolve Thermostat, I have to wire in 3 wires (one at C, another at RH and the other at W1). I am assuming that I need to wire the Red to RH and the White to W1…C is unsure at this point. I can easily run another wire from my thermostat to my furnace for this 3rd wire that is needed. My question is, where do I connect this 3rd wire…or do I need to rewire something at the furnace end to make this work?
I have attached 2 pictures, one showing the furnace wiring diagram, the other shows where the red and white wires are physically connected to the furnace.[/quote]
The “C” is the 24v common wire. Most normal thermostats do not use this wire, but Z-wave need it to continuously power the z-wave Thermostat. The red wire you have sends 24v AC current to the old thermostat and when heat is on the 24v is passed back threw the white to kick the unit on. Just like a basic 2 wire light switch. The netrual wire never passes threw switch as it wasn’t needed. Well now you need it.
So yes run another wire from the 120 to 24v inverter to the thermostat. If you need more help to locate it let us know.
One thing that does not make any sense to me on the evolve Thermostat is, if I connect the Red wire to the RH terminal and the White wire to the C terminal, the thermostat powers up. However there is no furnace control when I raise the setpoint. This tells me that there is a constant 24VAC source between both wires…which to me is strange because when I connect the old thermostat back (Red wire to R & Rc terminals and the white to the W terminal, everything works fine. This does not make sense to me as I would assume that if I took out the old thermostat I would not measure any voltage between both wires. However, like I said above, the old one works.
I am assuming that I would connect the Evolve Thermostat as follows: Red to RH, White to W1 and C to the 24VAC side of the 120 to 24VAC transformer?
[quote=“pbrisebois, post:3, topic:181361”]One thing that does not make any sense to me on the evolve Thermostat is, if I connect the Red wire to the RH terminal and the White wire to the C terminal, the thermostat powers up. However there is no furnace control when I raise the setpoint. This tells me that there is a constant 24VAC source between both wires…which to me is strange because when I connect the old thermostat back (Red wire to R & Rc terminals and the white to the W terminal, everything works fine. This does not make sense to me as I would assume that if I took out the old thermostat I would not measure any voltage between both wires. However, like I said above, the old one works.
I am assuming that I would connect the Evolve Thermostat as follows: Red to RH, White to W1 and C to the 24VAC side of the 120 to 24VAC transformer?[/quote]
What you have is a back feed of common (which is hooked up to the furnace and passing threw it). I like to show my guys in the automotive world a test with a good light bulb. I use 12v battery to show people this safer. Take a two wire light bulb and hook up the ground to one terminal. Now if you apply power on the other terminal the light will light up, but without the power hooked up if you check it for voltage you will find that it has ground. The filament in the bulb is passing the ground threw from one pin to the other (it has continuity and resistance, if its a good bulb).
The white wire and red wire twisted together will turn on the furnace as power it passed back threw the white wire to complete the circut. but with the white wire disconnected or opened in the thermostat the common is back-feeding from the common going into the furnace.
Hope this makes sense.
Yes you wire diagram is correct. You will not touch the 120 side of the 120v AC to 24v AC transformer. DON’T GET THAT MIXED UP.
You will see that the common or 24v “C” wire is already going to the heater, you just need to add another wire from anywhere along that wire to the thermostat “C”. This could be at the transformer, at the heater or anywhere in the middle.
I am having a similar issue with the T100R. I have four wires being used in my current thermostat.
R - 24VAC Return
G - Fan
W - Heat Stage 1
Y - Cool Stage 1
When I opened up my thermostat it had a blue wire (possibly 24VAC Common?) but it wasn’t connected to anything. I tried setting it up with all five wires but the T100R never booted up. Connected my old thermostat and it still works.
I am having a similar issue with the T100R. I have four wires being used in my current thermostat.
R - 24VAC Return
G - Fan
W - Heat Stage 1
Y - Cool Stage 1
When I opened up my thermostat it had a blue wire (possibly 24VAC Common?) but it wasn’t connected to anything. I tried setting it up with all five wires but the T100R never booted up. Connected my old thermostat and it still works.
Any suggestions?[/quote]
Yea use the extra blue wire and connect the other end to the 24VAC in the airhandler.
Did you get it going? Do you need help finding the 24v common inside the airhandler?
Bottomline 95% of installs don’t have a common wire to the thermostat as it was never needed. But if you have extra wires running threw the wall all you need to do us make sure the you attach each end of that wire to the right 24v common connection. on the thermostat you can see in your instructions. The other end wont be hard but different for each unit.
I have old wiring with only 4 wires at the thermostat - R,B,W,G and at the furnace a separate wire that has a white connected to the Com24v and red connected to the Y, these wires run directly out to the air conditioner. Is there a way to hook this thermostat up using just the 4 wires coming out of the wall without having to run more wires? It will be really hard to get new wires run. Panel on my furnace has G, Com24v, W,Y,R.
Thank You integlikewhoa - That looks like it will work. Thinking for price I may try spending 1/2 a day running 5 wire through a very old crawl space. I will report back if I use that item. Thank you again.
I am having the same issue and I THINK I have tried everything mentioned here.
I have a propane system. 1 heat stage. 3 wires.
White is attached to W1 on both the furnace and the thermostat.
Red is attached to both R on the furnace and the thermostat.
A green wire was not attached to the furnace but was run through as part of a bundle.
At the furnace, I combined the green and red wire.
At the thermostat, I attached the green wire to C.
No display, and nothing happens when I tap the arrows.
I used a volt meter to verify current.
Black probe on meter to white wire, red probe on meter to red wire: 24v
Black probe on meter to white wire, red probe on meter to green wire: 24v
Put the panel back on - still no display.
I am having the same issue and I THINK I have tried everything mentioned here.
I have a propane system. 1 heat stage. 3 wires.
White is attached to W1 on both the furnace and the thermostat.
Red is attached to both R on the furnace and the thermostat.
A green wire was not attached to the furnace but was run through as part of a bundle.
At the furnace, I combined the green and red wire.
At the thermostat, I attached the green wire to C.
No display, and nothing happens when I tap the arrows.
I used a volt meter to verify current.
Black probe on meter to white wire, red probe on meter to red wire: 24v
Black probe on meter to white wire, red probe on meter to green wire: 24v
Put the panel back on - still no display.
I am having the same issue and I THINK I have tried everything mentioned here.
I have a propane system. 1 heat stage. 3 wires.
White is attached to W1 on both the furnace and the thermostat.
Red is attached to both R on the furnace and the thermostat.
A green wire was not attached to the furnace but was run through as part of a bundle.
At the furnace, I combined the green and red wire.
At the thermostat, I attached the green wire to C.
No display, and nothing happens when I tap the arrows.
I used a volt meter to verify current.
Black probe on meter to white wire, red probe on meter to red wire: 24v
Black probe on meter to white wire, red probe on meter to green wire: 24v
Put the panel back on - still no display.
What am I doing wrong? :-([/quote]
You need to have 24v between the RH and C wire.
In the picture it looks like your probeing the wrong wires.
I’m also not sure what you mean combining the green with the red wire. One is power the other is common or gound.
At the furnace, the red wire and green wire are attached to R and the white wire is attached to W1
When I use the meter on the wires coming out to the thermostat, white and red have 24v, white and green have 24v, red and green have nothing.
I’ve tried switching the wires at the thermostat… no display.
At the furnace, the red wire and green wire are attached to R and the white wire is attached to W1
When I use the meter on the wires coming out to the thermostat, white and red have 24v, white and green have 24v, red and green have nothing.
I’ve tried switching the wires at the thermostat… no display.[/quote]
What good is it to have the red and green wires attached to the same place? Your problem is there!
Red wire comes from the power on the transformer in the furnace.
Green wire needs to be the ground wire coming for the furnace. It can not also be power.
Think of a light bulb it needs a power and a ground. You attach both wires (green and red) to the positive the light will never come on. You need to get the green wire in the furnace hooked up to the other low voltage wire of the transformer in the furnace.
See, THAT is what I thought, too. Originally. Then when the furnace guy came out (because I told him he needed to make this work), HE had no idea why it wasn’t working, either. The instructions clearly say this is a common and a return. To mean that means a complete circuit which indicates a hot and a ground. But when I connected the wires so that they matched the points (W1 to W1, R to R, C to C), I get the same results - no display. I started wondering if I’d forgotten all my high school electronics lessons and whether 24v C and 24v R meant that both needed to have 24v running to them. Apparently not. :-[
I’ve already had several emails to the company and they were no help. They tried, but kept telling me to send pictures. Now that I have the pictures, I opened up a new ticket for help (as I can’t find the previous one in my records) but have yet to receive a reply. So, I thought I’d come here.
What I did find out last night was that I can’t seem to get anything from the furnace itself. So odd. I used the meter on the points at the furnace and got no voltage for any of them. The wires were sticking through (slide through and tighten the screw down) so I used the wires themselves for contact with the meter probes. Nothing. Came back to the other side of the wires at the thermostat - voltage. There’s only one sheath of 3 wires going from the furnace to the thermostat. I don’t get it! I’m close to calling the furnace company again and telling them to come back out and try again. What do you think? I mean, I’m obviously not electricanally inclined. hahahah Never have been.
Maybe I’m not understanding you. But what I’m hearing with voltage on wires at thermostat but no voltage on heater.
That sounds to me like wires are not going from thermostat to heater and something else is connected in between.
Where is the actual 120 to 24v transformer?
Usually on new acs and heaters this is physically inside the air handler. But it has 2 wires in and 2 wires out. That converts 120v to 24v. Start there as that will be were both the R and C first begin the journey of sending power to your thermostat.
This may be remotely mounted somewhere if you have an old heater.
I thank you so much for your time. Are you ready for this? I re-seated all the wires and lo and behold - it’s working.
I hadn’t tried to just verify that the contacts were being made at the furnace - I trusted that the technician from the company who installed it would have been able to tell that.
Thank you, again for your time. It’s working exactly as expected - as per the wiring documentation. ;D
