Thermostat Wires

5 years ago

Just wondering why my thermostat wires would not be connected the terminal tha maches their color. as you can see on the picture, the
Black wire is connected to W
White wire connected to R
Red wire is capped/taped off
would this mean that my black wire is actually my heating control and the white wire is the 24v?
would the red wire be the control wire then?
any insight here?

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Comments (7)

HU-867564120
5 years ago
Maybe whoever installed your stat was color blind. Or maybe they didn't care. Whatever, all that really matters is that the wire connections at the furnace match the connections on the stat. Granted, to have put the colored wires to the 'correct' screw can help troubleshooting later on.
Chris
Original Author
5 years ago
thank you.
when installing the new thermostat, should I put the white wire to W, red wire to R and black wire to C?

or as it currently is? Black to W, White to R, and Red to C?
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Chris
Original Author
5 years ago
here is the furnace side, first section is the thermostat wiring. 1 red, 2 is white. no clue where the black wire by the thermostat is from.
mike_home
5 years ago
How old is this house? Old houses with boilers used on two thermostat wires which were usually black and white. A furnace may have been installed at some point. There could be a splice somewhere between wires.

The terminal the wire is connected to and not its color determine the function of the wire. The R terminal is 24V AC, the W is for heat. When calling for heat the thermostat connects the W terminal to the R terminal. This causes the furnace to turn on. If you are replacing the thermostat you need to put the wires on the the same terminals as they were previously connected.
HU-867564120
5 years ago
Ditto Mike.
dennisgli
5 years ago
At the furnace it looks like the wires are white, red, blue, and green - so it does like like the wire is spliced at some point.

But - bottom line is that you probably connect the white and black to the new thermostat and leave the red disconnected. If the new thermostat needs more conductors then I would replace the wire.
Chris
Original Author
5 years ago
This house was built in the early 1950s, originally oil, but now is a HE gas system.

Whole issue here is my new thermostat needs a "C" wire. Was hoping one of those 3 wires in the wall were that C wire. there are workarounds, but would rahmther not have done that.

i'm assuming when the new gas furnace system was installed, they set it up with the green/blue because that was what he had on had or incase needed in future.

i will see if i can find the 4 wire cable and see of i can locate a splice anywhere that feeds to the thermostat.