Nest 2nd Gen add C and * wire


  #1  
Old 03-19-20, 02:29 PM
F
Member
Thread Starter
Join Date: Mar 2020
Posts: 6
Received 0 Upvotes on 0 Posts
Nest 2nd Gen add C and * wire

I have a 4 wire thermostat cable and despite trying my best, I couldnt get it replaced with a 7 wire cable that I bought (cable is stuck somewhere). I see some videos where it explains how to use the G wire as C wire. My question is how do i now use the * wire for Aprilaire 600M humidifier. Would add a wire work? Someone posted that i need 2 add a wire(One for C and one for *). Would appreciate your help. currently i have a honewell wiresaver but planning to remove it.
 
Attached Images    

Top Answer

 
03-21-20, 12:31 PM
PJmax's Avatar
PJmax
PJmax is offline
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,470
Received 4,052 Upvotes on 3,635 Posts
Ok..... I modified the diagram for that model based on your installation.
The purple jumper between G and Y can be any type of wire.... even bare.
The H in the circle is the humidifier solenoid.

Name:  aaw.JPG
Views: 508
Size:  57.1 KB


 
  #2  
Old 03-19-20, 04:17 PM
A
Member
Join Date: Jun 2012
Location: USA
Posts: 1,499
Received 92 Upvotes on 84 Posts
Not cheap as you would need something like a Fast-Stat to add 2 wires. Model 3000 or 5000 - https://www.fast-stat.com/
 
  #3  
Old 03-19-20, 05:54 PM
F
Member
Thread Starter
Join Date: Mar 2020
Posts: 6
Received 0 Upvotes on 0 Posts
Can i not use the add a wire module (venstar)and wire the green as * and connect it directly to one of the solenoids?
 
  #4  
Old 03-19-20, 06:23 PM
A
Member
Join Date: Jun 2012
Location: USA
Posts: 1,499
Received 92 Upvotes on 84 Posts
To do it right you would have a G wire at Nest. Since you don't have it now maybe you wouldn't miss it.

So yes, you could use the Venstar. You would first remove the Honeywell module and put a jumper wire on the furnace terminals between Y and G. Then install the Venstar Add-A-Wire with one end of its green going to the humidifier and the diode at Nest going to *. Other connections as shown in the installation instructions https://files.venstar.com/accessorie...ManualRev2.pdf .
 
faisal zaman voted this post useful.
  #5  
Old 03-19-20, 07:50 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,470
Received 4,052 Upvotes on 3,635 Posts
I had problems with the conversion modules and the nest thermostats.

Now I only install wifi stats (especially the nests) with the correct cable.
Adding a humidifier on top of this will not help the situation.
 
  #6  
Old 03-20-20, 10:29 AM
F
Member
Thread Starter
Join Date: Mar 2020
Posts: 6
Received 0 Upvotes on 0 Posts
Thanks a lot. One more question. Can I get away without using the relay for humidifier?
 
  #7  
Old 03-20-20, 10:32 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,470
Received 4,052 Upvotes on 3,635 Posts
An Aprilaire 600 requires 24vAC on the solenoid wires to operate.
It doesn't require a relay in this situation.
 
faisal zaman voted this post useful.
  #8  
Old 03-20-20, 11:02 PM
F
Member
Thread Starter
Join Date: Mar 2020
Posts: 6
Received 0 Upvotes on 0 Posts
Mounted it to the vent. Waiting for venstar to arrive(Amazon). Question on wiring:
I read that i don't need to use the provided transformer. So I connect one yellow wire from the solenoid to C on furnace and the other one to Green wire in Venstar (* wire)?

For testing, if I connect the other wire to W, it should keep running while the heat is on right?
 
  #9  
Old 03-21-20, 09:21 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,470
Received 4,052 Upvotes on 3,635 Posts
Venstar ? What exact model are you using ?

One solenoid wire to C is correct.
The other solenoid wire needs to be connected to or controlled by the * terminal on the nest.
 
  #10  
Old 03-21-20, 11:45 AM
F
Member
Thread Starter
Join Date: Mar 2020
Posts: 6
Received 0 Upvotes on 0 Posts

Venstar ACC0410 Add-A-Wire Accessory for All 24 VAC Thermostats (4 to 5 Wires)


so I was planning to join y and * wire to the y diode and then connect the corresponding * to solenoid with a wire twister
 
  #11  
Old 03-21-20, 12:31 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,470
Received 4,052 Upvotes on 3,635 Posts
Ok..... I modified the diagram for that model based on your installation.
The purple jumper between G and Y can be any type of wire.... even bare.
The H in the circle is the humidifier solenoid.

Attachment 113538


 
Astuff, faisal zaman voted this post useful.
  #12  
Old 03-21-20, 02:51 PM
F
Member
Thread Starter
Join Date: Mar 2020
Posts: 6
Received 0 Upvotes on 0 Posts
This is exactly what i planned. Thanks a lot..
 
 

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