What does E and Aux mean on thermostat?

August 21, 2019 13:59. Some HVAC systems support auxiliary heat (AUX) as well as emergency heat (E). Auxiliary heat is used when the balance point can no longer efficiently transfer heat from the outside air (usually about 35 degrees Fahrenheit).

Why does my thermostat say heat on Aux?

Turning your thermostat to “heat” came with an unexpected “AUX” function appearing. What does it mean? The “AUX Heat” mode is usually an indicator that it’s freezing outside, and your is heat pump is using a secondary backup heat source – your auxiliary heat—to keep your home at your set temperature.

Should heat pump and AUX heat run simultaneously?

The system is designed so that both can operate simultaneously. As long as the HP is producing some heat, it’s more efficient to use the HP for whatever Btu’s you can garner and allow the aux heat to be just that, auxiliary rather than primary.

What is the purpose of auxiliary heat?

So what is auxiliary heat? The role of the auxiliary heater is to work in conjunction with your heating system to keep your home warm when the outside temperature is too cold for the heat pump system to be efficient on its own.

Does AUX heat come on automatically?

Auxiliary heat is when the secondary heat source turns on automatically. This means, when the temperatures start to drop and your heat pump cannot produce enough hot air to warm your home the aux heat will turn on.

How do I turn off auxiliary heat?

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 long should auxiliary heat run?

The manufacturer advises keeping the minimum on time to 300 seconds to prevent the system from short cycling.

What is E heat on thermostat?

What is EM heat on thermostat settings? 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.

Does auxiliary heat cost more?

As we mentioned above, AUX heat usually costs up to 50% more than heat transfer, which means if your system is running on AUX heat when it shouldn’t be, your heating bill is likely going to be a lot higher than you’d like it to be. Our suggestion would be to reach out to a professional as soon as possible.

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.

Is AUX heat and emergency heat the same?

Auxiliary heating turns on automatically to help heat your home more quickly if the temperature drops suddenly. The emergency heat setting has to be manually switched on and should only be used in temperatures below 30 degrees.

What is the AUX setting on thermostat?

“Aux” is short for auxiliary heat. 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 is my auxiliary heat blowing cold air?

Heat Pumps
They also use auxiliary heat strips if the outside temperature is extremely cold. If these strips malfunction, the heat pump will blow cold air. Just like in the summer, the system requires the proper level of refrigerant. If the level is low, the heat pump cannot transfer heat efficiently.

How do I know if my auxiliary heat is on?

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 is stage1 AUX heat?

Stage 1 Aux Heating
First-stage auxiliary heating for heat pumps and multi-stage furnaces; provides supplemental gas or electric heat when the heat pump cannot meet demand.

Why is my AUX heat not working?

Auxiliary heat turns on but doesn’t produce heat due to clogged filters or venting systems, damaged reverse valves, lack of power, a bad thermostat, low refrigerant, and lack of maintenance. To fix these, it’s best to call an HVAC technician or electrician.

Can a bad thermostat cause aux heat?

AUX heat doesn’t respond to thermostat changes: Turning your thermostat down to ambient temperature should cause AUX heat to turn off immediately. If you notice that secondary heating keeps going even it’s warm inside or the thermostat is turned off, there’s probably something wrong.