Thermostat wiring - C wire

Reply

  #1  
Old 04-10-15, 03:44 PM
J
Member
Thread Starter
Join Date: Apr 2015
Location: United States
Posts: 2
Received 0 Votes on 0 Posts
Thermostat wiring - C wire

I would like to install a new thermostat in my house (wifi+touchscreen) and pretty much all of the models i'm looking at require a C wire. Taking the faceplate off my current thermostat, I have a red wire to RH, a jumper from RH to RC, a Y/yellow, W/white, and G/green wire (as pictured below). I also have a blue wire, which when I look at my control board, is not connected to anything as far as I can tell. I notice there is already a white wire connected to the connection labeled "COM 24v", but it does not run through the same bundle of wires that go to my thermostat. Is it safe to just connect the blue to the "COM" connection on the control board along with the existing white (not sure where the white one even goes, if anywhere)?
Name:  20150410_181620 [].jpg
Views: 6259
Size:  17.0 KB
Name:  20150410_175943 [].jpg
Views: 600
Size:  31.7 KB
Name:  20150410_175959 [].jpg
Views: 603
Size:  38.7 KB
 
Sponsored Links
  #2  
Old 04-10-15, 04:34 PM
B
Member
Join Date: Mar 2015
Location: Canada
Posts: 186
Received 0 Votes on 0 Posts
The white is most likely the 24 volt common going to your ac condenser outside.

It's okay to connect the blue to common if it's not being used for anything.
 
  #3  
Old 04-10-15, 04:55 PM
J
Member
Thread Starter
Join Date: Apr 2015
Location: United States
Posts: 2
Received 0 Votes on 0 Posts
Great, that's what I figured. Thanks!
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: