Honeywell RTH9580WF install help- C Wire problems


  #1  
Old 04-05-15, 06:36 PM
D
Member
Thread Starter
Join Date: Apr 2015
Location: USa
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
Honeywell RTH9580WF install help- C Wire problems

Good evening all,

I'm a bit stumped on the install for this thermostat. I am in the process of replacing my existing thermostat, however have run into a bit of a pickle with the lack of a C wire. The unit I am replacing is a 4 wire unit with no C. Just G, Y, W, R.

Now typically I would just Add a c-wire and run it to the furnace and add it to its respective location on the board. However, there is not the typically strip of screw style terminals. Just three spade style with only G, W, R. There is a screw style terminal labeled 24V HUM next to them, can i use this as my power source for the thermostat?

Im completely stumped and have attached a couple of photos of the board. Any help would be appreciated. I have looked everywhere and do not have an actual wiring diagram. It is a Janitrol unit if it helps at all. I have only been in the house for about three months and was really only replacing because the existing one stopped working all together...Name:  photo 2.jpg
Views: 530
Size:  37.8 KBName:  photo 1.jpg
Views: 1001
Size:  44.1 KBName:  photo 3.jpg
Views: 483
Size:  36.7 KB
 
  #2  
Old 04-05-15, 06:41 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 71,641
Received 3,324 Upvotes on 2,985 Posts
Welcome to the forums.

I'll need a full picture of the entire board or the part number off that board. The picture needs to be as large as possible to be effective.
 
  #3  
Old 04-05-15, 07:25 PM
D
Member
Thread Starter
Join Date: Apr 2015
Location: USa
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
Here hope this helps. I attached a photo of the bundle of wires coming FROM the thermostat. You can see there is no blue wire going to anything. They just snipped it all together. But also cut and attached wire nuts going somewhere. Let me know what you think.Name:  photo 1-1.jpg
Views: 423
Size:  50.3 KBName:  photo 2-1.jpg
Views: 468
Size:  34.4 KBName:  photo 3-1.jpg
Views: 401
Size:  39.3 KBName:  photo 4.jpg
Views: 383
Size:  50.2 KB
 
  #4  
Old 04-05-15, 07:36 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,640
Received 72 Upvotes on 65 Posts
Name:  Goodman common.JPG
Views: 429
Size:  40.2 KB

The wire that connects to the furnace body is "C" (24 volt common).
 
  #5  
Old 04-05-15, 09:38 PM
D
Member
Thread Starter
Join Date: Apr 2015
Location: USa
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
I had a feeling just based on the switch for the door sensor is run to that screw so it has to allow power to something i.e everything.

Worked perfectly. Thanks guys!
 
 

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