Help Replacing Chronotherm III Thermostat

caperren

So, the house I'm living in currently has an old Chronotherm III thermostat and I'd like to replace it with a newer VisionPro thermostat that was given to me at work. I've tried to figure out where the old connections should go but it's confusing me somewhat and I'd rather not fry everything by trying. I'll post what I've found so far below, as well as some pictures of the current wiring of the old thermostat.

Chronotherm 3 Model - T8611G 1004
VisionPro Model - TB8220U 1003

Current Wiring of the Old Thermostat (Everything under the TYPE category is my best guess)

Wire -> Letter -- Type

Red -> R -- Standard 24V AC Hot Line (Heating)
Blue -> C & X2 -- 24 AC Common Line and either seond stage heating or indicator lights
Black -> L -- Service Light
Green -> G -- Fan On
White -> E & W2 -- Emergency Heat Relay and Second Stage Heating
Orange -> O -- Engergize to Cool(Control Valve)
Yellow -> Y -- Cooling Call

Here is a LINK to pictures of the wiring that I've described above.

Any help getting the connections right would be helpful. Also, if someone could tell me what mode to set the new thermostat in (1H/1C, 3H/2C, etc...) that would also be great. Thanks for any help in advance!

Missouri Bound

Go online and fine the installation instructions for your "new" stat. That will help you determine what goes where. It won't hurt if you find the instructions for the old stat as well to verify where those wires go. You can also find installers information for the "new" stat as well which will guide you in programming. Make sure you power off first before moving any wires. It great you have a picture as well.

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Doc Holliday

R-24 volts
Y-cool
G-Fan
W-first stage heat
W2-second stage heat
C-common. No need for that x2 jumper from c, don't even think you have that x2 in the new stat
O-reversing valve

I think you can cap that black wire off, its an indicator. Maybe someone can chime in but with what I've posted your system will run normally.

Turn the breaker to the furnace in your home's electrical breaker panel OFF first.

2h/1c.

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Thanks.

caperren

I have the installation manuals for both, I just figured I'd get some outside opinions before I accidentally broke anything. And I will definitely be removing power before I do anything to the system.

It probably could be, however there is a screw terminal for L so I doubt it'd be a problem to connect it.

So, as of now these would be my connections.

Red - R & RC
Yellow - Y
Green - G
White - W1
Blue - C
Orange - O/B
Black - L

I'll test them out and see how it goes........

Forgot to hit post on this before I tested. Anyway, it's all working perfectly using the connections I've listed above. Thanks for everyone's help. This was what I originally figured the connections would end up being, but I like to play it safe.

Missouri Bound

Glad you got it working...

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