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View Full Version : 8 wire to 5 wire Thermostat swap


kycpl
Feb 19, 2009, 10:33 AM
I want to go from this Sears Weathertron :

http://home.windstream.net/eof/IMG_8489.JPG


To this Emerson Model 7903:
http://home.windstream.net/eof/IMG_8492.JPG

Is this possible?
and if it is can someone point out where the wires go from the old to the new?

here's what I'm thinking:
R should go to:do not use
T should go to: do not use
O should go to: Rh-Rc jumped
G should go to: G
Y should go to: Y
X2 should go to: do not use
B should go to: do not use
W should go to: W

Probably got it all wrong, Probably not even compatible thermostats, I've already called any/everyone I can without paying for it, no info available. Let the flames begin... ;0)

kycpl
Feb 19, 2009, 10:34 AM
Yeah yeah I'm going to check the inside and outside model numbers now... sheesh

hvac1000
Feb 19, 2009, 02:06 PM
They are not compatible. Sorry.

EPMiller
Feb 19, 2009, 02:19 PM
It appears that you have a heat pump. The Emerson does NOT have the capability to control the reversing valve and the emergency (most likely electric) heat.

KC13
Feb 19, 2009, 02:33 PM
Of course, if you REALLY want that thermostat, replace your system with something that will be compatible. What! This is America! You can if you want... :rolleyes: