View Full Version : Changing Thermostats
PWT07
May 14, 2010, 09:45 AM
I just moved into a new home and brought my White-Rodgers thermostat with me (Model# 1F78 5/2 Day PRGM).
I am trying to replace the thermostat that was in the house, a Bryant (Model# TSTATBBPB501).
The wiring is a bit different and I don't want to mess anything up so hopefully someone can help me with the wiring. I have attached pictures of the existing wall wiring and my new thermostat hookups.
Thanks in advance for the help!
KISS
May 14, 2010, 05:44 PM
You bought a HP thermostat. Won't work.
On the original stat R isn't labeled and is the red wire. On new stats Rc is connected to Rh. You can call that connection R.
C is optional. It provides power to the stat, so the stat doesn't have to rely on batteries except for power outs.
You need a 1H/1C conventional thermostat. The 1 refers to stages. You had a 2H/2C stat which is usually OK.
Joshdta
May 14, 2010, 06:17 PM
The bottom pic is your new stat?
Red to rh
White to w
Green to g
Brown to B? Does b say it is a common on your wiring diagram ?
Yellow to y
PWT07
May 14, 2010, 06:44 PM
the bottom pic is your new stat?
Red to rh
White to w
Green to g
brown to B? Does b say it is a common on your wiring diagram ?
yellow to y
Yes. The bottom picture is the thermostat I took from my old house. It was hooked up pretty much the way you said.
White went to W
Red went to RH
Green went to G
Yellow went to Y
I did not use B or O in my previous house and looking at the manual for the thermostat it does not say what B or O is used for. This diagram is the only 2 times it shows either B or O being used and it seems to be for a reverse valve.
Here is a link to the manual.
http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-6614.pdf
Joshdta
May 14, 2010, 06:47 PM
OK then leave the brown wire off. The rest of the wires should be the same. You have gas heat with a ac now?
KISS
May 14, 2010, 06:53 PM
So, it does work for conventional based on the manual.
Cap the brown wire.
Rc needs to be connected to Rh, otherwise Cool won't work or the fan won't work in the FAN ON position.
PWT07
May 14, 2010, 07:48 PM
ok then leave the brown wire off. The rest of the wires should be the same. You have gas heat with a ac now??
Yes, gas heat and AC in the new house as well as the old. The one that was throwing me was the Brown wire going to C, but if that's common I guess I don't need it like you both said since this unit comes with Batteries and I don't need power to the unit.
Rc is connected to Rh with that red jumper wire so I will just keep that in place just like I had it at my old house.
Thanks for the help KeepItSimpleStupid and Joshdta :D
KISS
May 14, 2010, 08:57 PM
Glad you got it.