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View Full Version : New thermostat(s) does not work... old does?


kjoboyle
Oct 28, 2010, 06:51 PM
My old thermostat is some ancient circular dial "Climatrol". My furnace is oldschool, I think the HVAC guy that came in the spring said 60s-70s. Anyway I have been trying to get a new thermostat in here for a year now. Last fall I tried to install a new basic digital thermostat with no luck...

Here are the color of the wires coming out of the wall that are hooked up to my old thermostat (which is now pumping out glorious heat on this cold, Wisconsin fall evening):

Red
White
Yellow
Green
Blue

When I put the new thermostat (I have tried 2 now) on they can only start the AC and my Fan... but not the heat. Both of the t-stats I installed ask that I do not attach any wires marked "B" or that are blue because they are "not necessary". I put all the wires where they go into the new t-stats and no heat... ever. Every time I put the new t-stats on I think "maybe I didn't wire it right or put the wires in the terminals good enough" etc etc, but I am crazy because I have triple checked every time. I have tried every thing with these new t-stats and cannot get the furnace to fire up!

Here is my theory... and this is where I need some help. I assume (from massive internet research) that I have some kind of heat pump or something (I have a gas furnace... I do know that for sure). I assume that I have a heat pump because the B wire, or blue wire is used to power these... I think. And these new t-stats, even though they say they do not need B wires to power them, may not need then for those that do not have a heat pump... but since I probably do have one I need to find a thermostat that is right for my system... right? Someone please help me!

Joshdta
Oct 28, 2010, 06:59 PM
Red- rh- jumped to rc
White-w
Green-g
Yellow-y
Blue-c

kjoboyle
Oct 29, 2010, 06:18 AM
The new t-stats do not have a "C" terminal. All they have are RH (and RC), W, G, and Y. Are you telling me I need to get a t-stat with a "C" terminal? BOTH of these new t-stats say "if you have a "B" wire, tape and tuck it away.

zanec
Oct 29, 2010, 11:22 AM
Sounds like you need a T-stat that will operate a heat pump.

Joshdta
Oct 29, 2010, 12:58 PM
Are they battrey stats? Digital? You do not need a c wire just help for changing battries all the time.