Going from T841A to a RTH3100C - http://www.hvacmechanic.com/ Forums

Original message

Plumberman

70.128.102.56

"Going from T841A to a RTH3100C" , posted Fri 25 Apr 23:51

I am trying to change my thermostat from a Honeywell T841A to a Honeywell RTH3100C I have a Heat Pump my old thermostat wiring was as follows
White - X
Blue - W2
Red - R
Green - G
Orange - O
Yellow - Y1
Y1 & W1 Jumpered

The new Thermostat has
E
Aux
Y
G
O
L
R
B
C

Tried to wire it by the instructions in the book but nothing will come on fan or anything
please help house is getting hot

Replies:

Plumberman

70.128.102.56

"Re(1):Going from T841A to a RTH3100C" , posted Sat 26 Apr 08:46

it s shows on the new wiere diagram RTH3100C that X can go to either E or C??? does it matter?

Houston204

98.196.66.53

"Re(2):Going from T841A to a RTH3100C" , posted Sat 26 Apr 14:46

Your old X=C as shown in the diagram.

I recommend removing the panel at your air handler to verify the color connected to C.

"Tip of the Day" Remember to remove power first.

Plumberman

70.128.102.56

"Re(1):Going from T841A to a RTH3100C" , posted Sat 26 Apr 00:17

the 4 numbers at the end of T841A are 1316

Houston204

98.196.66.53

"Re(2):Going from T841A to a RTH3100C" , posted Sat 26 Apr 00:24

That's the fist pic.

"Tip of the Day" Remember to remove power first.

Houston204

98.196.66.53

"Re(1):Going from T841A to a RTH3100C" , posted Sat 26 Apr 00:06

I think that you have your white and blue wires confused. This would pop the fuse in your air handler.

Post the 4 numbers after T841A
Verify the color of X (common) at your air handler. (Bet it's blue)

"Tip of the Day" Remember to remove power first.

Houston204

98.196.66.53

"Re(2):Going from T841A to a RTH3100C" , posted Sat 26 Apr 00:11

Most fancoils will have a blade type 5 amp automotive fuse.

older American Standard and Trane will have the old style fuse

"Tip of the Day" Remember to remove power first.