What does aux heat mean on a thermostat?
When the temperature inside your home drops a certain amount below the goal temperature (usually 1.5-2 degrees), your thermostat energizes auxiliary heat. The aux heat indicator on your thermostat lets you know when this is happening.
What is an AuX2 heat pump?
Heat pumps systems sometimes have a second, auxiliary heat source that helps warm your home quicker and keeps the home warm in frigid weather conditions when the heat pump cannot. Some auxiliary heat systems for heat pumps have two stages, hence AUX2.
What is the blue wire on a thermostat?
Blue or yellow wire for cooling (connected to Y). These thermostats are typical for heat pumps: HVAC devices that can cool and heat. To produce the airflow, a fan is needed (green wire). Take the control panel off and expose the wires in the old 4 wire thermostat.
What is a W1 wire on a thermostat?
Thermostat White Wire (“W1” or “W2” Wire) White wires are for heating. You will find them in gas furnace thermostats, for example, but won’t find them in air conditioner thermostats. W wires go directly to the source of heating; that may be a furnace (gas, electric, oil, you name it) or heat pumps (mini-split heat pumps included).
What color is the AUX wire thermostat?
Standard Thermostat Wiring Labels, Wire Colors and Their Functions –LabelsColorsFunctionsY1YellowCoolingY2Light Blue/Others2 Stage CoolingENo Fixed ColorEmergency HeatingX/AUXNo Fixed ColorAuxiliary Heating9 more rows•Aug 30, 2021
Which wire is aux heat?
X, AUX: Some heat pump systems can provide auxiliary heat. This wire sends a signal to your system calling for auxiliary heat if the outside temperature is too cold for the heat pump to work alone. A secondary heat source located in the air handler will kick on.
What does AUX mean on a Honeywell thermostat?
Auxiliary heatAux Ht or Auxiliary heat is the backup heat that turns on to help the compressor for first stage maintain your temperature setting. You know if the auxiliary heat is running when you see "Aux Heat On" in the thermostat's display. During this time both your Auxiliary heat and your compressor may be on at the same time.
What is W2 aux on thermostat?
The wire in the W2 connector controls the second stage of heat. Learn more about multistage systems. If you have a heat pump. If you have a heat pump, the W2 wire may control your auxiliary heat. Auxiliary heat helps heat your home when it's too cold outside outside for your heat pump to work efficiently.
Is auxiliary heat the same as emergency heat?
What Are Auxiliary Heat & Emergency Heat? Auxiliary Heat – This is the secondary heat source that turns on automatically. Emergency Heat – This is when you turn on the secondary heat source.
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.
When should AUX heat come on?
When should my auxiliary heat come on? When outside temperatures drop below 40 degrees. While undergoing the defrost cycle. When there is a 3 degree difference or more in the current temperature in your home and the thermostat setting.
Why is my AUX heat always on?
The AUX heat setting on an HVAC unit usually turns on when you need heat fast. If this secondary heating system is constantly running, it may mean that the weather outside is very cold or that the thermostat is set higher than normal. It's also possible that a part of the heat pump is malfunctioning.
When should I use auxiliary heat?
Auxiliary heat is needed when… Heat pumps are highly efficient to about 32°F. Below freezing, your heat pump simply can't draw enough heat from the cold air outside and will kick on its auxiliary heat mode to generate heat for your home.
Does W go to W1 or W2?
In a conventional system, W/W1 controls your heating system and, where applicable, W2 controls your heating system's second stage, which helps warm the home faster.
Can you jumper W1 and W2 on thermostat?
If W1 is only wired up, it will always run in 1st stage, 2nd won't come on unless W2 is wired to a two stage t-stat, or jumper to it.
What is W1 and W2?
W1 is the classification we use for galvanized steel hose clamps (according to DIN3017) that are used in no-corrosion environments. W2 is the classification for stainless steel hose clamps (combination of AISI430 and zinc plated screw) that can be used in corrosion sensitive environments.
How do I know if my auxiliary heat is on?
You will know when the auxiliary heat is on because 'AUX' will be lit up on the thermostat. You will know the emergency heat is on because that thermostat setting must be manually turned on.
How do I know if I have auxiliary heat?
Here's how you can tell: It says so on your thermostat: The next time temperatures plummet, take a look at your thermostat. If the display says “AUX,” this means your heat pump is in auxiliary mode.
What color wire is emergency heat?
whiteThe wires are typically arranged as follows: red for 24-volt hot, white for heat, yellow for cooling, green for the fan, and blue for common (although the common wire may be a different color).
How do I stop my auxiliary heat from coming on?
The easiest way to stop the auxiliary heat from coming on is making sure the temperature doesn't drop too fast. You can do that by adding more insulation to your home and closing doors to rooms you aren't using. Taking proper care of your HVAC system can also help.
How does aux heat work?
Your aux heat works in tandem with your secondary heat source and your home’s heat pump. Turning on emergency heat means you’re relying completely on the secondary heat source, which is a lot more expensive than running aux heat. Call a professional if your thermostat indicates aux heat is running even after outside temperatures reach 40 degrees ...
What does the AUX heat indicator mean?
If a heat pump is having a difficult time coming up to a certain temperature quickly due to extremely cold outdoor temperatures, the “aux heat” indicator means that a secondary heat source (generally gas or electric) has been deployed.
Why does my heat pump need aux heat?
Typically, your heat pump will energize the auxiliary heat strip inside your secondary heating source to help reach its set temperature more quickly. Basically, if your heat pump is struggling to maintain its goal temperature, your aux heat will turn on and give your heat pump a boost. Your thermostat determines when the auxiliary heat gets ...
What Does It Mean on My Thermostat?
If your aux heat indicator is on, it means your heat pump needs a little help reaching its target temperature setting. Aux heat comes from the same heat source as emergency heat, but aux heat works together with your heat pump, so it’s less expensive than emergency heat. Typically, your heat pump will energize the auxiliary heat strip inside your secondary heating source to help reach its set temperature more quickly. Basically, if your heat pump is struggling to maintain its goal temperature, your aux heat will turn on and give your heat pump a boost.
What wire does an air conditioner thermostat use?
All air conditioner thermostats have a red wire for power. You may also have Rc or Rh terminals for dual transformer systems; these are special cases in thermostat wiring.
What is the orange thermostat wire?
“O” or the orange thermostat wire is for reverse valve cooling. Most bigger heat pump manufacturers like Trane, Goodman, Lennox, and so on have the orange wire that goes to the condenser (located in the outdoor unit of heat pumps).
What is the red wire on an air conditioner?
Thermostat Red Wire (“R” or “Rc” Wire) Red wire or “R” wire is the power wire. They originate in the transformer (air conditioners; in the air handler) and provide the 24-hour volt AC power. All air conditioner thermostats have a red wire for power.
What is the black wire on a thermostat?
The black wire or blue wire (either color is used) is the C – “Common” wire. What does the C wire do? C wire is connected to the transformer and completes the 24V electric circuit. Newer thermostats have a continuously looped 24V circuit; in older models, the loop is completed only when the power is required (when you turn the AC on, for example).
How many wires does a Honeywell thermostat have?
With the basic Honeywell thermostat, you will find: 8 wire sockets to the left. 8 wire sockets to the right. Before we take the flathead screw to unscrew these, let’s first familiarize ourselves with the crucial part of any thermostat wiring: Wire codes and colors. Here’s where the thermostat wires go:
What is a thermostat?
Thermostats are the ultimate control hubs for HVAC devices such as furnaces and air conditioners. Thermostat wiring is a useful skill to know if you have to replace an old thermostat or just check if something is wrong with the new thermostat. With a little help, you can learn how to install a thermostat on your own.
How many sockets does a thermostat have?
As you can see on the thermostat base, you have 16 sockets, with letters C, R, W1, W2, O/B, G, Y1, Y2, BK, 2x RS, 2x ODT, AUX NO, AUX C, and AUX NC. With 2 wire, 3 wire, and 4 wire thermostats you don’t have all of these. That’s normal. You might also notice that all sockets don’t wire in them. That’s standard as well.
What is the Y wire on a thermostat?
Y, Y1, Y2: Whenever your thermostat calls for cooling, the Y wire is used to send a signal to your HVAC system telling it to fire up the air conditioner. Y1 and Y2 wires might be used instead if you have a two-stage system (i.e. a high level for extremely hot or cold days, and a low level for mild days). W, W1, W2: Just like the Y wire, the W wire ...
What does it mean when you replace a thermostat?
If you’re replacing your thermostat for the first time, you might notice that the wires are connected to different terminals, each of which is denoted by a certain letter. Here’s what those letters mean. Replacing a thermostat is really easy, but sometimes the terminal letters on your old thermostat don’t match up with the ones on your new ...
What is a K wire?
K: Honeywell wire saver modules combine the Y and G wires to form a single K wire that connects to the K terminal on some Honeywell thermostats. It’s used for systems that don’t provide a C wire but have a thermostat that requires one.
How many volts does a thermostat use?
Note: While thermostat wiring only utilizes 24 volts (thus it won’t shock you or is even detectable), it’s still a good idea to shut the power off to your entire HVAC system before replacing the thermostat, so as not to cause any issues with the electrical system as you work on it.
What does C stand for in HVAC?
C: This stands for the “common” wire in an HVAC system, and it provides power to the thermostat. Some systems don’t provide this, and it’s not necessarily required by every thermostat, since some can be powered by a battery or just “ steal ” power from other wires, but if your system has one and there’s a terminal for it on your thermostat, you should absolutely connect it.
Can you replace a thermostat with a new thermostat?
Replacing a thermostat is really easy, but sometimes the terminal letters on your old thermostat don’t match up with the ones on your new thermostat. Knowing what each letter stands for and what it’s used for can help you figure out which wire goes where on your new thermostat.
What is the C wire on an Ecobee thermostat?
Also known as the common wire, the C wire enables the continuous flow of 24VAC power that ecobee thermostats need to operate.
What do all the thermostat terminal letters/wiring labels mean?
Use the Thermostat Compatibility Checker to see if an ecobee thermostat will work with your system.
How many R wires are in a dual transformer?
With dual-transformer systems you’ll have two R wires—one from the cooling transformer (Rc) and one from the heating transformer (Rh). Learn how to install an ecobee thermostat in a dual-transformer system.
What wires are used for ecobee heat pump?
If you have a heat pump system with auxiliary heating, you will normally connect the wire labelled AUX/AUX1 or W2 to the ecobee’s W1 terminal. If you have two stages of AUX heat, connect the AUX2 wire to the ecobee’s W2 terminal.
What wires tell the compressor when to switch between heating and cooling?
On heat pump systems, the O and B wires tell the compressor when to switch between heating and cooling your home.
What controls the fan speed in HVAC?
Most HVAC systems feature a single fan speed. In multi-speed systems, fan speed is either controlled by the furnace control board or the thermostat.
What is an auxiliary heat pump?
Heat pumps systems sometimes have a second, auxiliary heat source that helps warm your home quicker and keeps the home warm in frigid weather conditions when the heat pump cannot. Some auxiliary heat systems for heat pumps have two stages, hence AUX2.
Where does the red wire come from on a thermostat?
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.
Where are thermostat wires terminated?
Remember, the wires coming from the thermostat are terminated in the HVAC equipment . Importantly, there is a high voltage inside the air handler, boiler, or other equipment where the wires terminate. Some HVAC system manufacturers provide a terminal strip board where the wiring is attached.
What does C stand for in thermostat?
C stands for common, and there is no universal color used for this terminal, although black is the most common color I’ve seen. For the thermostat, wiring colors code for this terminal (if equipped) consult with the installer. Finally, if that is not possible, then trace the wire out to the source.
Where is the R terminal on a split system?
R – The R terminal is the power. It is a red wire and comes from the transformer usually located in the air handler for split systems, but you may find the transformer in the condensing unit. For this reason, kill the power at the condenser and the air handler before changing or working on the wiring at the t-stat. Lastly, if you have a package unit, then the transformer is in the package unit.
What is the terminal for a heat pump?
O or B – These terminals are for heat pumps and the B t-stat terminal is used on for Rheem or Ruud and any manufacturer that energizes the reversing valve in heating mode for the heat pump. Furthermore, other manufacturers of heat pumps utilize the reversing valve for cooling. The O thermostat terminal is for this purpose. This wire goes to the outside heat pump condenser, for reversing valve control. Finally, this is for heat pump thermostats.
What terminal is used for second stage cooling?
Finally, many systems only have a single compressor but if you have two compressors (or a two stage compressor) which should only operate off of one thermostat then you need the Y2 thermostat terminal for second stage cooling.
What wire do you use for a reversing valve on a Trane?
If you have a Trane, Carrier, Goodman, Lennox, Ducane, Heil, Fedders, Amana, Janitrol, or any other manufacturer other than Rheem or Ruud, you will be utilizing the orange wire for reversing valve. Lastly, Rheem and Ruud will usually use the blue wire for the reversing valve.
Where do you put the C wire on a thermostat?
In some cases, one of those wires may be your common. If you have a C wire, place it into the C terminal on your wall plate. Let's take a look at the G wire. This wire will go to the G terminal on your new thermostat. For the Y, Y1, and Y2 wires, Y or Y1 will go to the Y terminal, and Y2 will go to the Y2 terminal.
How many wires does a thermostat use?
The thermostat uses 1 wire to control each of your HVAC system’s primary functions, such as heating, cooling, fan, etc. See the diagram below for what each wire controls on your system:
What to do if you see terminals labeled A B C or 1 2 3?
If you see terminals labeled A B C, or 1 2 3 then your new thermostat may not be directly compatible, as your system requires a communicating thermostat.
Do you tape off the B wire on a heat pump?
If you have separate wires for O and B, you will want to tape off the B wire so it can’t make contact, and the O wire will be connected to the O/B terminal on your thermostat. If your O or B terminal shares a label with another wire, typically W, you’ll need to identify whether you have a heat pump system or not.
Can you label wires that are not connected to a terminal?
Any wire that is present, but not connected to a terminal you will want to make a note of, but you will not label these wires.
Where does Y1 go on a wire?
For the Y, Y1, and Y2 wires, Y or Y1 will go to the Y terminal, and Y2 will go to the Y2 terminal.
Can you have more than one wire?
If you have more than one wire ( you have a wire labeled R, and another wire labeled Rc for example) you can remove any jumpers between the R and Rc terminals, or push the switch to open the RC terminal so you can insert a wire. Next, let's talk about the C, or common wire.
