thermostat installation-Honeywell


Old 05-17-07, 07:04 AM
Thread Starter
Join Date: May 2007
Posts: 1
Received 0 Votes on 0 Posts
thermostat installation-Honeywell

I am upgrading from an old honeywell T841 thermostat to a new Honeywell digital TH5220D.
My Heat Pump is a Carrier 38YCB from 1996
On the old T841 thermostat the wires are attached as follows:
The Yellow wire attaches to Y.
The Green attaches to G.
The Orange wire attaches to O.
The red wire attaches to R.
The brown wire attaches to X.
The white wire attaches to W2.
On the Heat pump unit the wire connections are the same except the brown attaches to C at the heat pump.
The new TH 5220D has the following terminals and designations:
Rc for 24VAC power from cooling transformer.
R for 24VAC power from heating transformer.
R and Rc are bridged together.
O/B for changeover valve.
Y for compresser contactor (stage 1)
G for fan relay
AUX for auxilary heat relay
E for emergency heat relay
L for sends output when set to emergency heat.
C for 24VAC common. C is optional with batteries.
How do I connect the new thermostat.
Sponsored Links
Old 05-17-07, 06:42 PM
Jarredsdad's Avatar
Join Date: Oct 2002
Location: Troy, VA
Posts: 1,532
Received 0 Votes on 0 Posts
Simple - original manual

Everything is pretty much the same as far as wiring.
R to R
Y to Y
G to G
X goes to C
W2 goes to aux
O goes to W O/B

Jumper E to Aux for em heat to work.

Look at page 4 of your installation book. What you call W is for conventional. Below that is O/b for heat pumps. You address this during programing.

This maybe the install manual for your old stat, you didn't give the entire model number so there is no X terminal.


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
Display Modes
Ask a Question
Question Title:
Your question will be posted in: