The most common thermostat cabling is 18/5 (18 gauge, 5 conductor), because 5 conductors typically offer enough functions for a modern thermostat/low voltage device.
What are the 5 thermostat wires?
5 Wire Thermostat Wiring (Any HVAC Device – Air Conditioners, Heat Pumps, Furnaces, etc.)
- Red wire for power (24V).
- White wire for heating (connected to W or W1 terminal).
- Green wire for fans.
- Blue or yellow wire for cooling (connected to Y).
- Black wire for “C” or “Common” wire.
Is thermostat wire different?
There are different types of red wires that a thermostat could have. Specifically, there are “Rc” wires and “Rh” wires. In simple terms, the Rc wires are for cooling systems while the Rh wires are for heating systems. Rc wires connect to your transformer’s 24-hour AC voltage.
How do you identify thermostat wires?
Look for connectors that have labels that are the same as your thermostat. For instance, you might find labels like R, W, G, Y, C or O/B. You should find wires attached to these connectors that are the same color as the wires that connect to your thermostat.
Can I use 22 gauge wire for a thermostat?
Nest thermostats require wires between 18 and 22 gauge, which is standard for residential heating and cooling systems. Anything smaller than 22-gauge wire could be too thin for a Nest thermostat to detect.
Is RC the same as C wire?
The C and Rc wires are not the same. To install this thermostat you should follow the exact same wiring of the previous thermostat.
What color is the C wire?
Blue wires
Blue wires are also called “C” wires because they are the Common wire. C wires are necessary for any “smart” thermostat that needs to be connected to a power source 24/7, regardless of your heat pump type.
What happens if you wire a thermostat wrong?
Potential consequences of improper installation could include: Electric shock. Blowing a circuit breaker. Damaging the thermostat unit, the electrical system or even the AC/furnace unit itself.
What is the difference between RH and RC thermostat wires?
RC: The RC terminal is the 24-volt cooling power supply. RH: The RH terminal is the 24-volt heating power supply. (Note: The RC and RH terminals are jumpered together in a four-wire heat/cool system and a single-stage heat pump system but not in a five-wire heating/cooling system.)
What is 7 wire thermostat wire used for?
If you have a heat pump system or a system that controls either the ventilation or humidity of your home, then you can have a seven-wire thermostat.
What AWG is thermostat wire?
18 gauge
The most common thermostat cabling is 18/5 (18 gauge, 5 conductor), because 5 conductors typically offer enough functions for a modern thermostat/low voltage device.
Is it OK to splice thermostat wire?
If you have to, you can splice the thermostat wire and generally, if the splicing has been done correctly, the thermostat’s function will not be affected. And as thermostats normally only need low-voltage power there are no safety regulations that prohibit the use of spliced thermostat wire.
Can I use 24 gauge wire for thermostat?
You’re taking a heck of a chance of a fire by using 24 gauge wire in this application. Don’t do it. Are you sure? HVAC thermostats are generally designed to drive a simple transformer, and 24VAC transformers generally take less than a few hundred mA to trip (the first one I saw used 40mA).
Can I connect C wire to R?
If the black wire on the R terminal goes to the thermostat and only the thermostat, you can safely move it over to the C terminal. The AC and humidistat being hooked up to C is correct. R and C together carry the 24v power that a smart thermostat (and some programmable models) use for power.
Does R wire go to RH or RC?
An R wire can go into a Nest Learning Thermostat’s Rc or Rh connector.
Do I use R or RC on thermostat?
If you have two wires, R or RH go into the R terminal and RC into the RC terminal. If you have more than one wire (for example, you have a wire labeled R and another wire labeled Rc), remove any jumpers between the R and Rc terminals or push the switch to open the RC terminal to insert a wire.
Do I need both RC and RH wires?
For heating and cooling systems, it will have a red Rc and a red Rh wire. Though both wires are red, they are not interchangeable. For the thermostat to work properly, the red wires must be connected to the correct corresponding terminal. The C, or common wire, provides smart thermostats with continual power.
Do I need a jumper between R and RC?
In most cases, the heating and cooling system share a single transformer by leaving the jumper in the lower right corner it connects the RC and RH to power heat and cool features. The only time this jumper would be removed is if the heating and cooling systems have their own transformer.
Do I need a jumper between RC and RH?
In most cases, the heating and cooling system share a single transformer by leaving the jumper in the lower right corner it connects the RC and RH to power heat and cool features. The only time this jumper would be removed is if the heating and cooling systems have their own transformer.
What does RC on thermostat stand for?
The RC wire, on the other hand, refers to “red cooling”. It’s the same with the RH wire in that it powers the thermostat. For the RC, it powers the cooling system.
What is Y on a thermostat?
Y – This is the terminal for cooling or air conditioning and goes to the compressor relay. Typically a thermostat wire pull is made to the air handler on split systems and then this wire is spliced for the separate wire pull which is made to the condenser.
