What Happens If You Wire A Thermostat Wrong?

What is the difference between R and RC on a thermostat?

RC is no different and simply means red cooling.

The wire is generally red, although there is no color standardization — but more importantly, the “R” really means that the wire and terminal are hot; it’s a live electrical wire.

The RC wire connects to the RC terminal, which controls the cooling system..

What is 2 wire thermostat?

If we put it simply, a 2 wire thermostat is one which has only 2 wires coming out of its backside. … When it comes to low voltage systems, a 2 wire thermostat is usually known as a “heat only thermostat” and is used for systems like a gas furnace (with only heating option).

What color wire goes where on a thermostat?

Here is the industry standard thermostat wire color code used for most systems: White. The white wire connects to your heat. Yellow.

Does R go to RC or RH?

Here are some general guidelines: An R wire can go into a Nest Learning Thermostat’s Rc or Rh connector. The Nest Thermostat E only has an R connector, which is typically where an R wire would go.

Are thermostat wires dangerous?

Even replacing a broken or outmoded thermostat usually is not too difficult. … Virtually all room thermostats operate on low voltage that carries little risk of harmful electric shock. However, it is always wise to shut off power to a thermostat at the service panel before examining or working on it.

What happens if your thermostat wires aren’t labeled?

If one or more wires in your current thermostat doesn’t have a label, don’t guess. … If any wires were not originally connected to your current thermostat (and don’t have a label), they typically aren’t connected to your system. Do not connect these wires to your current thermostat or Nest thermostat.

Why does my thermostat only have 3 wires?

If you have a heat-only system, you may notice that your thermostat has three wires—R, G, and W. … 1) Run an additional wire to use as a C from the furnace control board to the thermostat. 2) Re-purpose your G wire as your C wire, connecting it to the C terminal at both your furnace control board and your ecobee.

Where does the black wire go on a thermostat?

Finally, this way, you can match up the appropriate wire color coming from the thermostat to what it controls in the equipment. The red wire should always come from the hot side of the 24-volt transformer. Additionally, the common (sometimes black) should come from the common side of the transformer.

How do you test C wire on a thermostat?

It is easy to see if you already have a c-wire connected to your system. Simply remove your current thermostat face from its baseplate and look for the terminal labeled with the letter “c.” If this terminal has a wire attached to it, you have an active “c-wire.”

Can a thermostat be wired backwards?

Sounds like you just got a wire or two hooked up wrong somewhere (common error). Sometimes new stat terminal maybe a little different than old stat. Can you please post a pic of the thermostat terminal and control board terminal on hvac unit?

How many wires should my thermostat have?

4 wiresNote on Thermostat Wiring for Communicating HVAC Systems Communicating systems use only 4 wires. However, the basic wiring principle is the same: Each wire must connect to the furnace or air handler terminal and the corresponding thermostat terminal.

Where do thermostat wires go?

The yellow wires underneath your thermostat connect to your compressor. They control your air conditioning system. The yellow wires terminate at your compressor contactor via an air handler. The yellow wires connect to the Y terminals on your thermostat.

Can a thermostat cause a fire?

These thermostats are considered to be a fire hazard. The safety commission reports that contact between the thermostat wires and household line voltage can damage the thermostat and cause a fire. … There have been eight reports of burn damage to the thermostat causing minor property damages.

What if there is no C wire for thermostat?

If your current thermostat didn’t need a C-wire, it (or a wire that can be used as a C-wire) might be rolled up inside the wall. This is more likely to be true if you see all the other color wires present. Line voltage thermsotat scenario: you have just two wires (white and red, probably), and they’re thick.