My current digital thermostat only had the red wire hooked up and the black wire was no not connected and ran off batteries. I measured the voltages and couldn’t find 24vdc nor 24vac anywhere. I replaced with the z wave TZEMT400BB3NX and the panel doesn’t turn on - I’m guess it has no power. Is this standard to use 24vac and where do I install a 24vac adapter? Are there battery powered z wave thermostats to avoid this hassle?
When I installed my thermostat I didn’t have 24vac either. I opened my furnace up and found that it could provide 24vac so I hooked up the lead to an unused wire and then plugged that in to the t-stat accordingly. Worked great, I haven’t had any problems and I actually like not having to worry I’m going to rip the thing off the wall to put in batteries every few months.
I can provide pictures of my furnace with annotations of what I did if you think it might help you.
I ended buying a 2gig Ct100 that’s supposed to work off battery power and going to return this one. The 2gig works on either or so I guess if I have time to fix the 24v then that’s a better solution. The wire is there so I just need to figure out where in the furnace that wire goes to. Pics would def help if you have a chance but it’s not a life or death thing so please don’t worry about it if you are busy.
Go to youtube and do a search for “c wire thermostat” the video titled - “C Wire - How to power the thermostat via an additional transformer” by the user homehandyman101 explains how to do this.
Basically, you use a standard 24 volt standard power supply that plugs into an electrical outlet and power your thermostat this way.
For a more streamlined finish, you can use a 24volt transformer search for “how to wire low voltage transformer”.
Good luck.
[quote=“shifter775, post:2, topic:172738”]When I installed my thermostat I didn’t have 24vac either. I opened my furnace up and found that it could provide 24vac so I hooked up the lead to an unused wire and then plugged that in to the t-stat accordingly. Worked great, I haven’t had any problems and I actually like not having to worry I’m going to rip the thing off the wall to put in batteries every few months.
I can provide pictures of my furnace with annotations of what I did if you think it might help you.[/quote]
I did the exact same thing today. I searched this forum because I thought I was going to have the exact same problem, but I discovered that the lines in the wall had FOUR extra wires, and I simply used one of those and wired it in on the furnace end and the thermostat end. I can’t for the life of me understand why they wouldn’t have simply set up the old thermostat with a C wire, since the old thermostat supported it (it also used batteries). Not sure why they wouldn’t just use the wire since they had it, but oh well, I’m just glad it was there.
[quote=“davet, post:4, topic:172738”]Go to youtube and do a search for “c wire thermostat” the video titled - “C Wire - How to power the thermostat via an additional transformer” by the user homehandyman101 explains how to do this.
Basically, you use a standard 24 volt standard power supply that plugs into an electrical outlet and power your thermostat this way.
For a more streamlined finish, you can use a 24volt transformer search for “how to wire low voltage transformer”.
Good luck.[/quote]
You may not need an additional transformer; it may already be there. Mine was. My old (non- Z-wave) thermostat didn’t require power so the original installer did not connect the “c” or “common” wire in the furnace. Connecting the unused wire in the cable to the “c” terminal in the furnace provided the 24 VAC to the thermostat so no constant battery drain.
In my case, I just had to connect the spare wire (in the t-stat cables) to the 24VAC terminal block inside the zone controller.