The E wire controls emergency heating. Emergency heat is used when the HVAC system is not functioning properly (usually when the compressor is out of service). When you set a thermostat to emergency heat, the system bypasses the compressor and directly accesses the electric heat strip.
Should thermostat be on E or F?
Factory-set in the “F” position, the thermostat fan operation switch is labeled FUEL SWITCH. It’s the correct setting for most systems. The switch should be set to “E” if you have an electric heat system.
What color is E on a thermostat?
Brown
Thermostat Wiring Color Code Chart
| Marking | Wire Color Code | Description |
|---|---|---|
| E | Brown | Emergency heat relay |
| Y | Yellow | Primary cool call relay |
| Y2 | Yellow | Secondary cool call relay |
| G | Green | Fan relay |
What does heat E mean on a thermostat?
Short for emergency heat, it is a setting that controls your home’s back-up heating system. If you have an emergency heat thermostat setting, you likely have a heat pump, as well as a gas, oil, electric, or hot-water back-up system.
Where does the e wire go on a Honeywell thermostat?
The E terminal has a back-up heat source. If you have a heat pump package unit, the E terminal should be wired directly to the heating relay or the stripboard of the air handler.
When should AUX heat come on?
Aux heat should only kick on when the heat pump can’t produce enough heat to warm your home on its own. This is typically caused by one of three factors: when it’s below 35° outside, you’re trying to heat your home by 3° or more, or your heat pump is in defrost mode.
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 W2 and Y2 thermostat?
Y2 – This is the thermostat terminal for cooling second stage if your system is so equipped.W2 – This is the thermostat terminal used for second stage heat. There are gas furnaces with low fire and high fire and some depend on control from a two-stage heating thermostat with a W2 terminal.
Where does orange wire go on thermostat?
The orange wire connects to terminal O on your thermostat. The orange wire only applies to homeowners with an air-source heat pump. Only air-source heat pumps connect to your outdoor condenser. Homeowners with geothermal heat pumps have no use for the orange wire.
Where does the heat come from for defrost?
What is a defrost cycle? In heating mode a heat pump extracts heat from outside air and transfers it to inside your home to warm it. When the ambient temperature outside gets very cold, the moisture in the air freezes on the outdoor unit’s heat exchanger as the fan blows the air across it.
Why is my heat blowing cold air?
Your furnace may be blowing cold air because the filter is too dirty. A dirty air filter blocks airflow over the furnace’s heat exchanger, causing it to overheat. When overheating, your furnace can trip a high limit switch, causing the furnace burners to shut off so that the heat exchanger does not crack.
Should fan be on auto or on for heat?
Keeping your fan on AUTO is the most energy-efficient option. The fan only runs when the system is on and not continuously. There is better dehumidification in your home during the summer months. When your fan is set to AUTO, moisture from cold cooling coils can drip and be drained outside.
Is W2 and e wire the same?
W2 is generally called on based on a temperature differential between setpoint and space, outdoor temperature, or run time. W3 This is just the next stage of heat after W2. E Is emergency heat, usually just a way to manually drive on what would normally be the secondary form of heat without stage 1 heating.
How many wires does a thermostat need?
The most basic thermostat has 2 wires; usually a red and a white wire. Two wire thermostat wiring is used for furnaces only and usually doesn’t need a C or Common wire. That’s why we only need two wires: Red wire for power (24h).
Will AUX heat turn off?
Your thermostat inside your house is actually what determines when the auxiliary heat gets turned on.This commonly takes place once the indoor temperature on your thermostat reaches 2-3 degrees colder than the set indoor climate temperature. Aux heat will turn off once your home reaches the thermostat set point.
How do I turn off the auxiliary heat on my Honeywell thermostat?
One of the simplest things you can do to keep your Honeywell thermostat from switching to auxiliary heat is to lower the temperature in your home. Setting the thermostat for somewhere between sixty to sixty-eight degrees is all you should need to do to get the problem under control.
What does AUX heat mean on Honeywell thermostat?
Aux Ht or Auxiliary heat is the backup heat that turns on to help the compressor for first stage maintain your temperature setting.When the thermostat is in this position the compressor does not run, only the Emergency heat runs.
How do I know if my thermostat needs batteries?
The most obvious sign that you need to change your thermostat batteries is when the thermostat literally tells you the batteries are about to die! Most programmable models will now flash a low battery warning, usually about a month or two before the battery completely dies.
What do the batteries do in a Honeywell thermostat?
It has a LED screen and push-button controls, and it’s suitable for conventional heating/cooling systems and heat pumps. The batteries are for backup when the thermostat is connected to 24-VAC power. You should replace them once a year. Switch the system to OFF.
How do I know if my thermostat needs a battery?
Check the screen: Check the screen of the thermostat and make sure that it is lighted. A blank or unlighted screen could indicate a thermostat failure. Check the batteries: Many modern thermostats rely on battery power to operate. If the screen is blank or unlighted, a battery change could solve the problem.
How do I know if my Honeywell thermostat is bad?
The most obvious sign that your thermostat might be bad is if it has no power or is unresponsive. If there’s no change in your home’s temperature when you adjust the temperature, or the display is unlit or unresponsive, you might have a broken thermostat on your hands.
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