Should auxiliary heat come on?

Asked By: Lai Ansola | Last Updated: 2nd June, 2020
Category: home and garden indoor environmental quality
4.2/5 (225 Views . 44 Votes)
Emergency heat is the same thing as auxiliary heat. Auxiliary heat/ Emergency heat help the heat pump keep up when cold outside or the temperature differential on the thermostat is large. Auxiliary heat/emergency heat will come on when the heat pump is in defrost.

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Furthermore, at what temperature should auxiliary heat come on?

Auxiliary Heat. Auixiliary Heat will turn on automatically when heat can no longer efficiently transfer heat from the outside air to heat pump. This is when the outside is around 35-40 degrees and the indoor temperature is around three degrees cooler than the thermostat setting.

Secondly, is auxiliary heat the same as emergency heat? I guess the only difference is that AUX is an 'indicator' on your thermostat that you are running the heat strips when the switch is set to HEAT. Emergency Heat is just the switch setting that will turn off the heat pump and only run the auxiliary heat. Emergency Heat Indicator only when in Em. Heat Mode.

Keeping this in consideration, how do I stop my auxiliary heat from coming on?

To limit auxiliary heat and lower your heating costs, a critical first step is to set a lower indoor temperature. If it's 30 degrees outside, it is unreasonable to expect the system to maintain an indoor temperature of 78 without using the heat strips.

How much more expensive is auxiliary heat?

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.

37 Related Question Answers Found

Is it normal for AUX heat to 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.

Why does my thermostat says auxiliary heat on?

Aux on the thermostat stands for auxiliary heat. Emergency heat is the same thing as auxiliary heat. Auxiliary heat/ Emergency heat help the heat pump keep up when cold outside or the temperature differential on the thermostat is large. Auxiliary heat/emergency heat will come on when the heat pump is in defrost.

Why is my furnace blowing cold air instead of heat?

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.

Why is my auxiliary heat blowing cold air?

Due to their design, heat pumps blow colder air than gas and electric furnaces. 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.

How do I know if I have 2 stage cooling?


How Do I Know If I Have a Single Stage or Multi-Stage Heating System?
  1. Check your thermostat for variable heat settings, such as low and auxiliary heat.
  2. Locate the model number of your furnace, either by checking in the product manual or by looking directly on the front of furnace or inside the front panel.

What does it mean when your thermostat says aux heat on?

Turning your thermostat to “heat” came with an unexpected “AUX” function appearing. What does it mean? TheAUX 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.

Why Does My Honeywell thermostat say auxiliary heat?

"Auxiliary heat" means the secondary heating source. You have the thermostat set to keep your maximum temperature at a certain point, at which the device providing heat turns off. Your thermostat has two possible heat sources, a main and an auxiliary. It depends on how the unit was wired which heat source is which.

Is it cheaper to leave heat pump on all day?

According to Energywise, you shouldn't leave your heat pump on all day. As the weather gets colder, it might be tempting to leave your heat pump on all day. Hoerning said heat pumps are the most efficient way of using electricity to heat your home, but there are many ways people could use them more efficiently.

How do you reset your heat pump?

Reset the system by turning it off with the thermostat or breaker if your unit has a safety device locking it out. Wait 60 seconds and turn it back on. It may take up to 10 minutes for the outdoor unit to start.

Why does my heat keep turning on and off?


This is most common cause of short cycling. A dirty air filter restricts air from getting into your furnace. Your furnace's heat exchanger needs that air blowing over it or it overheats, causing the furnace to shut down. Change (or wash, if you have a washable type) your air filter if it's dirty.

Should a heat pump run all the time?

Most heat pumps will run constantly during the cold weather. This means that it is normal for your heat pump to be running constantly during winter when the temperatures are at or below 30 degrees. However, if the heat pump is running constantly in the cooling mode during the summer, then there could be a problem.

Do all heat pumps have auxiliary heat?

When outside temperatures drop too low to allow the heat pump to extract heat from the frigid air, some systems switch on a backup heating system to supply the rest of the heat needed to reach the desired temperature inside. While some heat pumps have that auxiliary heating capability, others do not.

Does outside unit run on heat?

Heat Pump Operation
Therefore, when you run the furnace in the winter, the outside unit should not run as it only functions as part of your air conditioning system. Refrigerant absorbs heat from the outside air and moves it indoors with the help of a reversing valve and multiple check valves.

How does auxiliary heat work?

Auxiliary heat is a heating system that works when the temperature inside a home or building drops lower than two or three degrees from what the temperature is set. Or when someone decides they are cold, and turns the thermostat up more than three degrees. Auxiliary heat is a component of heat pump systems.

At what temperature do heat pumps become ineffective?


If you are impatient, I won't make you wait; heat pumps don't work well below 25-30 degrees Fahrenheit. But what you might not know is that the heat pump temperature range is broader than most people think, and with the addition of supplemental heating it can work even in the chilliest of temperatures.

How do I know if my heat pump is working properly?

The fastest way to determine whether you have a heat pump or not is to turn the heat on at your thermostat. Once you feel hot air coming through your vents, walk outside and see if the outdoor unit is running. You see, a heat pump is an air conditioner that can also provide heat during the winter.

How long should my furnace run?

If your furnace is operating correctly, it should cycle about 2 to 3 times per hour. How long it operates depends on how cold it is outside. In milder temperatures, it may run for 10 to 15 minutes. The colder it gets, the longer the run cycle will be.