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])

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.

Thanks, I read that somewhere else, but wanted additional input.

No problem

Quote:

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Originally Posted by hvac1000

No problem

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

Unit?
Are you talking about the electric furnace unit? OR the thermostat?

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

Quote:

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Originally Posted by hvac1000

Unit?
Are you talking about the electric furnace unit? OR the thermostat?

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

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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.

According to this Honetwell document you should not have a problem.

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

OR

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