What color wire goes where on a thermostat?

What Color Wire Goes Where On A Thermostat?

The following picture shows the inside of a thermostat. You can see that there are two wires going into the thermostat.

These two wires are called brown wire and white wire. Brown wire is used for heating elements while white wire is used for cooling elements. There are many types of thermostats available today. Some have both heating and cooling elements. Other thermostats only have one type of element. All these different types of thermostats require different kinds of wiring to work properly. It is important that the proper wires are connected to the correct terminal.

How To Wire A 4-wire Thermostat

4-wire thermostats are very common. If you have any doubt about the type of wiring to use in your house, consult a professional.

Also note that it is important to know the type of heating and air conditioning system that you have. The picture above shows a 4-wire thermostat.

As you can see there are two separate wires coming in and only two wires going out. Different types of heating and air conditioning systems use different types of thermostats. If you do not know the type of heating and air conditioning system that you have, consult a professional. The white wire is the same on both sides. These wires are interchangeable. Either wire can go to either terminal. The red wires are also the same on both sides. Again these wires can be switched if necessary.

The first thing that you will want to do is turn off the power to your heating and air conditioning system. This can be done by finding the right breaker in your fuse box and flipping it.

There are two separate brown wires. One wire goes to the B terminal and the other wire goes to the W terminal. Once this is done you can begin removing the old thermostat. Most HVAC systems in houses are held in place by two screws on the top of the unit. These can be removed with a standard Phillips head screwdriver. Once these are removed the entire thermostat should come out easily. Next you will have to find where your wires go. This should be done with a multimeter. A multimeter is an instrument that will tell you whether or not two wires are connected. They also let you know the strength of the connection. First you will have to remove the front cover of the thermostat. This can be done by removing the screws holding it in place and prying it off carefully. Once this is done you should see something that looks like the first picture.

Start by doing the B terminal first. Place the probes on the two terminals with the red and white wires.

If it beeps, then the wires are connected. If not, move on. Next, do the same thing for the W terminal. After that you should be finished. If the multimeter did not beep for either of the terminals, then the wires do not connect to that terminal. In this case, the brown wire is not connected to the B terminal and the white wire is not connected to the W terminal. You can now connect your new thermostat by connecting the wires to the proper terminals.

The brown wire is connected to the B terminal using a gas proof connector. The white wire is connected to the W terminal using a gas proof connector.

The red wire is connected to the R terminal using a gas proof connector. A new hole must be drilled in the furnace for the E terminal. This is connected using another gas proof connector. The wires are then covered with electrical tape. The front of the thermostat is put back on. The wires can now be carefully arranged around the cover. Finally, the cover can be screwed back into place. Now the thermostat is finished and ready to be placed.

what color wire goes where on a thermostat on remodelingmate.com

The first thing to do is make a hole for the E terminal. This is the larger of the two outside terminals on the front of the thermostat.

The smaller one is the R terminal. The old thermostat had a plastic plate that went over these two wires. You will have to drill out this plate in order to expose the wires. If you can’t get a drill small enough, then you can try to pry it out with a screwdriver. Once you have removed the plastic plate, unscrew the two screws holding the thermostat in place. Pull the old thermostat out and you will see two wires coming from the wall. One is black and the other is red. These are connected to the E and R terminals. Next you can tape the wires to the wall and put the new thermostat in place. The E and R terminals are larger than the other two terminals so they can be easily identified. Once you have these two terminals covered by tape, then you can tape the wires coming from the wall to them.

The final step is to place the thermostat in its location. All that needs to be done is to put the two screws through it and into the wall.

This will hold it in place and complete your install.

Ignore the white and blue wires in this section. The white wire was for the humidifier option and was not installed in all furnaces.

The blue wire was for a bypass that was only used if the old thermostat did not have a E or an R terminal. Once again, these wires weren’t installed in all furnaces so if you don’t have them then you are lucky and don’t need to do anything about them.

DANGER: This is a very dangerous situation! If you don’t have the white and blue wires then your furnace will not work properly.

You need to find a way to connect these two wires together. The best way to do this is to twist bare wires together and tape them with electrical tape. Make sure that they are not likely to come apart. If you do not have the white or blue wire then you need to get a new thermostat that does have these wires.

Once you are finished, your furnace should work just like it did before. Turn the furnace power back on at the breaker panel and give it a try.

Congratulations! You have now successfully changed your thermostat to a new one without spending a lot of money.

what color wire goes where on a thermostat - Picture

Quiz: What type of thermostat do you have? Find out here.


Sources & references used in this article: