PDA

View Full Version : Thermostat upgrade


aaa1950
Oct 5, 2009, 05:48 AM
I need help. I have a Trane XL 1200 heat pump (central heat/air) with an existing Weathertron Baystat239 thermostat. I want to replace the 239 with a Honeywell RTH7500D programmable thermostat. The 239 utilizes the following terminals:
O
G
Y
T
R
W
B

The conversion chart for the 7500D shows the following connections:
O to O
G to G
Y to Y
R to R (with jumper to RC)
W to Aux (with jumper to E)
B to C
T (is not mentioned)

What is the connection for T?
Al ([email protected])

hvac1000
Oct 5, 2009, 06:05 AM
You will not use the T wire from the old thermostat since the new style thermostats will not have the Trane T wire usage available. NOTE The T wire is not necessary for proper operation.

aaa1950
Oct 5, 2009, 06:13 AM
Thanks, I read that somewhere else, but wanted additional input.

hvac1000
Oct 5, 2009, 06:22 AM
No problem

aaa1950
Oct 5, 2009, 06:29 AM
No problem

Just thought of something that may or not be important. My unit has an aux heat and emergency heat function. Will that matter?

hvac1000
Oct 5, 2009, 06:45 AM
Unit?
Are you talking about the electric furnace unit? OR the thermostat?

The new thermostat can accommodate that setup just look at the instructions.

aaa1950
Oct 5, 2009, 07:03 AM
Unit?
Are you talking about the electric furnace unit? OR the thermostat?

The new thermostat can accomodate that setup just look at the instructions.

The thermostat has a blue indicator light for when the aux heat kicks in, it also has a manual switch for emergency heat (red indicator light). The HVAC unit has electrical heat strips for extra heat.

Just trying to cover all bases. I should have mentioned that in the beginning so you would have the information to consider.

Thanks.

hvac1000
Oct 5, 2009, 12:13 PM
According to this Honetwell document you should not have a problem.

http://customer.honeywell.com/TechLit/pdf/PackedLit/69-2104ES.pdf

OR

http://customer.honeywell.com/TechLit/pdf/PackedLit/69-2221EF.pdf