View Full Version : Replacing an old with a new digital thermostat
sksmq
Jan 10, 2009, 12:55 AM
Old Honewell T8195B has 1 red, 2 white and 2 green wires. Replacing with new digital honewell Rth230B, marked with Rh, Rc, W, Y and G. Any suggestions how to connect.
MarkwithaK
Jan 10, 2009, 01:00 AM
Well for starters, what terminals were the wires attached to in the first place?
If you are unsure then you will have to look at he terminal board on your furnace. The stat wires will correspond with the terminals on your new stat.
NOTE: You will not see either an Rh or an Rc terminal on your furnace. Just R. In most case you will have to install a jumper wire from Rh to Rc on your stat unless you are using a 2 transformer system.
sksmq
Jan 10, 2009, 01:16 AM
Well for starters, what terminals were the wires attached to in the first place?
If you are unsure then you will have to look at he terminal board on your furnace. The stat wires will correspond with the terminals on your new stat.
NOTE: You will not see either an Rh or an Rc terminal on your furnace. Just R. In most case you will have to install a jumper wire from Rh to Rc on your stat unless you are using a 2 transformer system.
From SKSMQ; Both are for C/A, heating and air with no marking on old
MarkwithaK
Jan 10, 2009, 01:26 AM
Ok, did you look at the terminals on your furnace where the stat wires terminate? If you can't or won't then there is nothing myself or anyone else on here can do to help you. The wiring colors your submitted do not adhere to the general rule of thumb.
KISS
Jan 10, 2009, 01:28 AM
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