How To Turn Off The Auxiliary Heat On A Honeywell Thermostat

Ossiana Tepfenhart
by Ossiana Tepfenhart

Honeywell thermostats are recognized as some of the best heat control devices a home can have. They also happen to have a tendency for using auxiliary heat pretty heavily. The problem is that excess auxiliary heat use can be a drain on your heating bill and may even contribute to higher energy bills. So, how do you turn this feature off?

You can turn off the auxiliary heat on your Honeywell thermostat if you set the temperature at 70 degrees. Set the temperature between 60 and 80 degrees to keep the house at a regular temperature and avoid auxiliary heat. Evenly distribute the temperature in your house and improve your insulation to prevent an auxiliary heat backup.

Seeing that auxiliary heat light turn on can be a little alarming. But, it’s really nothing to worry about. This guide will help you understand what triggers auxiliary heat and how you can prevent it from lighting up in your home.

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Do All Honeywell Thermostats Have Auxiliary Heat Functions?

Honeywell is known for having a wide range of different thermostats, each of which is designed for its own optimal HVAC system setup. Though they often have an auxiliary function, not all of them do. Auxiliary heat is primarily used in heat pump-based HVAC systems. This means that you probably only have auxiliary heat if you have a heat pump. We have an article on auxiliary heat, if you want to read more.

If you have a furnace or use a boiler for your heating, then you probably don’t have to worry about that auxiliary heat. A good way to know if you have an auxiliary heat function is to check for a light that says “AUX,” for auxiliary. All Honeywell thermostats designed to work with heat pumps will have an auxiliary heating method.

What Is Auxiliary Heat Supposed To Do?

If you have a thermostat that uses heat pump technology, then you have an auxiliary heating method. Your auxiliary heating method is a backup heater. It only kicks in when your HVAC system’s heat pump is not capable of raising your home’s temperature to the level that you’ve requested.

Auxiliary heat should not be something you regularly rely on, as it increases your heating bills and can wear out your HVAC. It relies on electric conduction, rather than your heat pump, to work. As a result, it’s not very effective or efficient at keeping your home warm.

When Should Auxiliary Heat Turn On?

Your auxiliary heat should only turn on when your heat pump is no longer capable of drawing in heat from outside efficiently. Most Honeywell units will kick on the auxiliary heat when the following is true:

  • The temperature outside is below 40 degrees Fahrenheit. The majority will only start to kick in then, with others preferring a lower temperature of 30.
  • Your internal home temperature is three degrees lower than what you want it to be on a cold day. This kind of discrepancy will get picked up by your thermostat and will trigger the auxiliary to kick in.
  • There is just not enough power to the heat pump to handle the demand of the cold. Sometimes it is a heat pump issue. Just saying.

Is Auxiliary Heat The Same As Emergency Heat?

It’s not your emergency heater, but it’s darn close. Auxiliary heat is a backup that acts like a helping hand to run alongside your heat pump. Your primary heat source (the heat pump) works in tandem with your secondary heat source (electric conduction) to give you the toasty interior you love.

Usually, emergency heating only happens when you manually request it. It also means that the same system that runs your auxiliary heating is going to provide 100 percent of the heat rather than 50 percent or so. With that said, many people do not really distinguish between the two in casual speech.

Why Can’t You Turn Off The Auxiliary Heat?

This is a good question, and much of it has to do with your heat pump. Your HVAC system’s number one purpose is to ensure that you’re comfortable and that you have heat throughout your home. If you shut off your auxiliary heat, your heating system won’t be able to function properly. It might even go straight to your emergency heating, which is something that should only be done in extreme situations.

As annoying as it may be to lack that level of control when it comes to your heating system, it’s something you’re going to have to deal with. This isn’t exclusive to Honeywell thermostats, either. Almost every thermostat that has an auxiliary heat function will bar you from turning it off.

Why Is Auxiliary Heat So Bad?

It’s not bad, per se, but it is auxiliary heat is inefficient. It takes a lot of energy to power an electric conduction system to the point of being able to heat a house. In short spans of time, this can be negligible. Over the larger course of time, you may notice that your heating bills will start to rise dramatically.

Is It Always Possible To Avoid Auxiliary Heat?

Here’s the thing that you need to be aware of: auxiliary heat isn’t always avoidable. The way heat pump HVAC systems work is that they’re designed to be used in areas that are generally warm. They are not meant for places like Alaska or Michigan, since these systems work by siphoning out heat from the outside and pumping it indoors.

The thing is, even warm areas will have days where it’s just too cold for a heat pump to adequately function. For example, if it’s -20 degrees outside, your heat pump will not be able to get enough heat to keep your home comfortable. At this point, you need to have a backup source of heat.

How Can You Prevent Your Auxiliary Heat From Turning On?

Though you cannot manually shut off your auxiliary heat, you can do things to prevent it from kicking in—to a point, anyway. To do this, you either have to raise your home’s temperature or lower the burden of your heating system. These measures below help prevent auxiliary heat from turning on through a variety of different means:

  • Decrease your thermostat’s temperature. This is the easiest way to avoid kicking off your auxiliary heat. If your thermostat has a lower temperature, the heat pump won’t need to work as hard. If the heat pump doesn’t work as hard, it won’t run the risk of needing a backup.
  • Add extra insulation to your home. The best way to make it easier for your heating system to reach your target temperature is to ensure that heat can get trapped inside your home. Good weatherstripping, eco-friendly windows, and even having a nice rug on your floor can make it easier to keep heat inside.
  • Close doors to rooms that are not in use. You won’t care if other rooms are cold, and neither will your thermostat in most cases. While this doesn’t always work, it can be a remarkably quick fix in some situations.
  • Use a space heater. Sometimes, you may need to make the choice between your auxiliary heat and another source of heat. Your thermostat will still pick up a temperature increase, even if it’s not from your furnace. By using a space heater you have on hand, you avoid auxiliary power.
  • Clear out your HVAC filters. Experts agree that you should be changing your furnace filters every 30 days. If you haven’t been doing this, then there’s a good chance that you’re making your heat pump work harder than it has to. By cleaning out your filters, you’re improving airflow throughout your home and decreasing the amount of heat that needs to be generated to properly warm your home.

Are There Any Thermostat Brands That Allow You To Turn Off Auxiliary Heat?

Unfortunately, there is no thermostat offering that allows you to do a manual shutdown of your auxiliary heat if you have a heat pump. It just doesn’t work with the way that thermostats work.

Should I Be Worried If My Auxiliary Light Is On During Warmer Weather?

Considering that your auxiliary heat is supposed to be your “helper” rather than your main source of heat, you should be worried if your AUX won’t turn off. Usually, this is a sign that there’s some part of your HVAC system that isn’t working the way it should. If you want to make sure that you don’t have high heating bills, do a diagnostic on these parts:

  • Filters. Filters that are dirty clog up your home’s vent system, which makes it hard for hot air to push through. Clogged filters are the key cause of overtaxed heat systems. Try replacing your filters to see if things improve.
  • Blower Motor. The blower motor can go bad and cause cold air (or no air) to blow through your system. Sadly, there’s not much you can do here aside from replacing the motor.
  • Vents. In order for your home to be able to be properly heated, you need to make sure that the hot air travels through the vents to the destination room. If you have a break in the vent, then the air will leak out. The leak will cause your heat pump to go into overdrive, requiring auxiliary heating to kick in.
  • Heat Pump. Though heat pumps are known for being durable, it’s still possible for them to go bad. If you notice that your pump doesn’t sound right or is regularly unable to pump air, this is the cause of your auxiliary light being unable to shut off.
  • The Thermostat. Sometimes, thermostats just don’t read temperatures correctly. It could be that your thermostat is on the fritz and it’s not reading your temperature correctly. This is usually the culprit if your home is toasty but still requires auxiliary heating.

When Should You Call A Professional?

If you cannot diagnose the reason why your auxiliary heater is still running, or if you feel like there’s something you’re not seeing, then you should call a professional. After all, HVAC systems are fairly complex and should not be seen as a simple fix in most cases. Whenever you need a more thorough inspection, a professional is going to be the best possible.

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Related Questions

How can you tell if your auxiliary heat is on?

Finding out if your auxiliary heating is on is a cinch. All you have to do is take a look at your thermostat’s face. If you have a heat pump heating system, then you will have an auxiliary heat system that will be signified by a light labeled “AUX.” This stands for “Auxiliary.”Just look at the light to find out what’s up. If the AUX light is on, then your auxiliary heating system is currently turned on and is providing your heat. If it’s off, then your auxiliary heating system isn’t adding heat to your home.

Should I get a house with a heat pump heating system?

Heat pump heating systems are best left for places that have high temperatures year-round. This is because heat pumps literally pump heat from the outdoors into your home. If you live in an area that’s generally warm year-round, such as Texas or Florida, then a heat pump HVAC system is a great way to save money on heating.However, heat pumps are not for every home. Houses built in areas that are prone to cold don’t fare well with these systems. So, if you live in Michigan or New York, you might want to check out other options. Furnaces and boilers might be a better choice.

How long should I expect a thermostat to last?

This all depends on the type of thermostat you have as well as the type of usage you’re looking at. Most thermostats should be able to last a bare minimum of 10 to 15 years before they need replacement. This, of course, assumes that you are capable of maintaining the thermostat and that you aren’t doing things that could contribute to their deterioration.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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