[esquire1]

I have honeywell T8411R 1028 (2) wired
G= grn L
C=blue W2=white
R=red E=brwn
W1 jumpered with yel B
Y =yel O=orange

I want to change to Honeywell Y594G 1252
It has:
W3 O Y
E
W2 L
G R X
How would this new one need to be wired?

[labman]

Neither follows the conventional terminal markings. You will have to refer to the directions for the Y594G 1252 to determine where to connect power from the thermostat, and which terminals it switches the power to for heat, cooling, and fan. If the furnace has the same markings as the old thermostat, you may need the directions for one of them to identify the functions. Some of the terminals may be for an outside temperature sensor, different firing rates, or mode controls for a heat pump.

Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire, common, to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. Most thermostats and furnaces have the contacts labeled R, B or C, W, Y, and G for the corresponding wire colors. It may be wired to have the A/C control wires return to the furnace and its controls and then a second wire goes to the A/C unit. Internal wiring may replace the green wire if the thermostat does not give you the option of fan only or continuous fan. Digital or programmable thermostats may need the blue wire connected to them.

Nobody here gives HVAC answers like Tom does plumbing. Often I can be more helpful.

[esquire1]

It is a Goodman model A32-15. I looked inside air handler and it is:


R to trans (red wire)
G to blower time delay (green wire)
O
W1/W2 to M3(brown wire)
W2 to M5 (yel wire)
E
C to blower time delay (blue wire)
OTC
OT1
OT2
OT3
Thermostat wire is R=red-G=grn-O=orange-W2=white-E=brown-C=blue-OT3=yel. Also W1/W2is jumpered with a brown wire to OT1 and W2 is jumpered with a yellow wire to OT1. THere is a spade type connector to W1/W2- W2 & E Does any of this make any sense?

[labman]

I am afraid not to me. You are just going to have to use any instructions you have, the manufacturer's websites, and perhaps tech hot lines to identify what the cryptic terminal markings mean and which terminal does what. There are a couple of other guys that jump in with answers here, but I haven't seen ones as specific as you want. Many times I can't do much more than help people figure out their problem.