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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Replacing a weathertron bay28x139 or bay28x141 with a

Customer Question

replacing a weathertron bay28x139 or bay28x141 with a white-rodgers 1F86-244. after matching all colors from the old weathertron to the new white-rodgers I have two extra wires. (black that it was connected to x2) and (brown that it was connected to T) system isn't working, not sure if this thermostat is compatible or if those two wires need to be connected. or if the whole wiring is wrong. I pull up the instructions for the new thermostat and is very confusing.
JA: I'll do all I can to help. Is there anything else important you think the HVAC Technician should know?
Customer: system was working with the old thermostat but not with the new one
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the HVAC Technician about your situation and then connect you two.
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

Tell me what color wires went to what terminals on old and where you put them on new.

Expert:  airheatman replied 1 year ago.

If you connected the blue wire from B on old to B on new, you most likely blew a small fuse in the air handler .That B will have to go to C on new.Let me know and we will go from here.

Customer: replied 1 year ago.
Old Thermostat: R=Red, O=Orange, G=Green, Y=Yellow, X2=Black, B=Blue, W=White, T=Brown. New thermostat terminals: W, RH, RC, B, G, O, Y. Missing on the new one: X2 and T. In fact I did follow the color code and I blew the fuse and system was dead, I replaced the fuse and installed the old thermostat and all is working as it suppose to. Still want to install the new thermostat.
Expert:  airheatman replied 1 year ago.

Give me a few moments to look over

Expert:  airheatman replied 1 year ago.

OK after looking over the manual on the new thermostat I see that it is not designed to work with your heat pump with backup heat .It will work with the heat pump, but you will not have the electric backup strips if you choose to use this thermostat.It is considered a single stage heat/single stage cool thermostat.You need a 2 stage heat/1 stage cool thermostat.

If you chose to use this thermostat and sacrifice the backup heat ,

You will wire as follows:

Red to RC with jumper to RH (24v power)

Orange to O (Reversing valve)

Green to G (Fan)

Yellow to Y (AC contactor)

All others taped off. Let me know and we will go from here.