The Right Thermostat? (Honeywell Says Two Diffrerent Things) - HVAC - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 10-10-2010, 05:58 PM   #1
Newbie
 
Join Date: Oct 2010
Posts: 5
Rewards Points: 10
Default

The Right Thermostat? (Honeywell says two diffrerent things)


I have a Rheem RGDA-100C-ER natural gas furnace, with a dual fuel kit (now running propane) and a CP-84R AC/heat pump. I'm in central Ohio, so it runs as a heat pump almost all winter with propane emergency/aux heat kicking in on a few cold days (and a/c in summer of course).

I tried to swap out the old thermostat for a Honeywell RTH7600, which is what Honeywell recommended.

The old thermostat has:
X, W2, R, G, O, Y, E, B.

The wiring diagram on the furnace control board has:
R, Y, B, O, W2, E, G, C (W2 and E are jumpered together).

The new thermostat:
Rc, R, O/B, Y, G, C, L, E, Aux.
The new one expects an L, and says I could run X to two places, but both already have wires in them (C that now has old B, and E). The instructions say panic!

Is there some way to use this thermostat, or is it going back to the store?

Advertisement

FourIsWaltz is offline   Reply With Quote
Old 10-10-2010, 06:38 PM   #2
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,526
Rewards Points: 4,690
Default

The Right Thermostat? (Honeywell says two diffrerent things)


B, on your old stat is the same as the O/B on the new one.

You don't need to use L.

Advertisement

beenthere is online now   Reply With Quote
Old 10-10-2010, 08:19 PM   #3
Newbie
 
Join Date: Oct 2010
Posts: 5
Rewards Points: 10
Default

The Right Thermostat? (Honeywell says two diffrerent things)


Thanks for the help, but I still don't quite understand. If I stick B into O/B, what do I do with O?

Wiring from the furnace to the new 'stat, trying to follow Honeywell's instructions:

'stat -- furnace
Rc -- nothing <-- (jumpered to R at the stat)
R -- R
O/B -- O <--(instructions say if there's an O wire, put B into C.)
Y -- Y
G -- G
C -- B <-- (but now what do I do with C?)
L -- nothing
E -- E
Aux -- W2

...and C from the furnace is just dangling there.
FourIsWaltz is offline   Reply With Quote
Old 10-10-2010, 09:20 PM   #4
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,526
Rewards Points: 4,690
Default

The Right Thermostat? (Honeywell says two diffrerent things)


Rheem uses B to energize the RV on a heat call. So your B from your outdoor unit should go on the O/B terminal.

You might want to write down what wires are connected where at your furnace and heat pump. And then post that info.
beenthere is online now   Reply With Quote
Reply


Thread Tools
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Honeywell Thermostat Wiring Differences DavidHwang HVAC 16 01-28-2012 03:11 PM
new honeywell RTH4300 thermostat to replace older one randysd Electrical 4 09-03-2010 11:20 AM
New Honeywell thermostat connected to old Climatrol heat pump olorintf HVAC 0 08-24-2010 10:52 AM
Honeywell RTH7600D Thermostat brewmastr HVAC 1 01-03-2010 09:10 PM
honeywell chromotherm thermostat - help? mkbgriffen HVAC 4 12-26-2006 01:46 PM




Top of Page | View New Posts