Converting from a Trane XT500C AC Thermostat to Honeywell TB8220U1003 VisionPro 8000

hvacthermostat

All,
I am trying to upgrade my Thermostat and am very confused how to connect the wires correctly (Florida house built 1991, AC and heat strips, no furnace):
As is, Trane XT500

  1. Blue to B
  2. Red to R
  3. White to W
  4. Green to G
  5. Tan to O (I think this is supposed to be Orange)
  6. Yellow to Y1
  7. Jumper W to X2

On the Honeywell:

There is B/O not B and O as separate connections.
There is no W.
There is no X2.

Available Connections are:

on Left:

  • Y2
  • L
  • A
  • W1
  • S1
  • S2

on Right:

  • RC
  • R
  • O/B
  • Y
  • G
  • C

I would greatly appreciate any help!!!! This should be easy, but I don't want to guess.
Here is the Trane (before) image:enter image description here

Here is the Honeywell Replacement (VisionPro 8000 TB8220U1003):enter image description here
As you can see we ran the wires from what seemed obvious/reasonable, but didn't know what to do with the white wire. Also, we connected the Blue and Orange (tan) wires together into the O/B slot. Don't know if that is good or bad.

tag on air handler
tag on air handler
tag on air handler

enter image description here

enter image description here

![mid wiring diagram
]8

Diagram from booklet

Best Answer

Trane nomenclature's a bit different

Trane decided to be different (and a bit difficult) with their heat pump thermostat nomenclature: while O is indeed the reversing valve connection, they called the common B (blue) instead of C (for Common). So, your correct wiring is:

  • White (W on the old 'stat) goes to W1 on the new 'stat
  • The jumper from W to X2 on the old 'stat gets discarded (X2 was emergency heat, but the Honeywell is smart enough to mux that onto W1 in heat pump mode)
  • Red (R on the old 'stat) goes to R on the new 'stat (the R-RC jumper stays put)
  • Tan (O on the old 'stat) goes to O/B on the new 'stat (some other people designate the reversing valve terminal as B, but Trane went and used that for the common terminal instead)
  • Yellow (Y1 on the old 'stat) goes to Y on the new 'stat
  • Green (G on the old 'stat) goes to G on the new 'stat
  • and Blue (B on the 'old stat) goes to C on the new 'stat (not to O/B where you have it now)
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