Calling all HVAC experts

psylichon

Genius
Moderator
Oct 31, 2007
16,591
751
113
40
Philly
#1
I'm trying to install a Nest Learning Thermostat alongside a Crown AWR-series natural gas boiler. The Nest doesn't charge properly with my 2-wire R/W thermostat line due to power-stealing from the controller, so I'm trying to add a third conductor (C). I've run the line, but I can not figure out where on the controller to connect it... mine doesn't have a dedicated C terminal. It should tie to common ground, but that doesn't seem to work.

My thread on the Nest forums:
https://community.nest.com/message/1705#1705

Honeywell S9361A controller manual: https://docs.google.com/gview?url=http://dl.owneriq.net/a/ad76b75a-c0f3-4a06-b130-ecea5f97dab3.pdf

Perhaps a long shot, but maybe someone here can clue me in on what I'm missing.

Other than the fact that I have to keep pulling the unit off and charging via USB, I love the Nest. Very slick unit. I just can't fully utilize it until it's charging on the wall.
 

RoofMonkey

Genius
Gold
Jun 21, 2010
8,871
2,048
113
Florida
#2
Run an extension cord? Haha, joking of course. Good friend of mine runs an AC businesss and they install the nest systems. Being in Florida, they don't run into boiler situations often, if at all, but I will certainly pick his brain for you.
Keep us updated & ill see if he has any thoughts on this.


Sent using iCafe app
 

Rugaby

Genius
Gold
Feb 18, 2011
7,122
1,219
113
Washington state
#3
Is your common ground a for real common ground or does it ground along with something else? Your new unit probably wants a dedicated three line system correct?
 

chris

Administrator
Administrator
Jun 10, 2006
11,812
1,778
113
Long Island, NY
#4
Wish I knew how to help. Have the Nest, but had an electrician install it. All I can say is that it's awesome once you get it up and running.