I have a York t-stat for a York system and purchased the 6300. My York t-stat has 7 wires (W, B, G, R, X, O, Y). Of those, the Honeywell instructions indicate that the 6300 will use C, G, W, Y, R, and possibly O or B. It says that if you have both O and B that you should install O and tape up B and not use it.

But it appears that W and O would be installed in the same slot.

Any ideas?

jbb

You must follow the diagram since they know what their product have to replace in the market. Most thermostats use 5 conductors and O and B are bull ox, LOL