The Role Of Auxiliary Heat In Efficient Heat Pump Systems

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By Debarghya Roy


Auxiliary heat is also called “emergency heat” or “secondary heat.” It helps when the outside temperature drops too low for your heat pump to keep your home comfortable.

Thermostats decide when they should turn on. Electric resistance heating or a supplementary unit transfer heat from one area to another.

Auxiliary heat is usually more expensive than the primary source of heating. To prevent this, set your thermostat correctly according to the outdoor temperature. Check insulation and weatherstripping too to make sure they are in great shape.

Understanding auxiliary heat lets you have a comfortable and energy-efficient home. Take action today to get the benefits.

If the heat pump goes on vacation, the auxiliary heat will make sure your home stays warm.

heat pump auxiliary heat

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What is Heat Pump Auxiliary Heat and How Does it Work?

To understand how auxiliary heat works for your thermostat in your heat pump system, let me explain it briefly. 

When the temperature drops outside and your heat pump cannot produce enough heat to keep your home warm, auxiliary heat kicks in automatically to help heat your home more quickly. 

This includes electric resistance heating and a heat strip inside your secondary heating source.

Electric Resistance Heating

Electric Resistance Heating is a non-combustible type of heat. It works by running electricity through a heating element, creating resistance and generating heat. This warmth is spread evenly in the room.

It’s become popular since it offers precise temperature control and energy efficiency. However, in cold weather or when thermostats are set too low, additional heating sources like oil-fired boilers or gas furnaces may be needed.

Invented by Thomas Edison in 1882, its use spread after WWII when energy and construction became accessible to the public.

Heat Strip Inside Your Secondary Heating Source

The heat strip is in inside your secondary heat source and it is an auxiliary heat strip. This activates when the temperature outside drops and the primary heating system can’t handle the load. 

It is made of metal coils that get hot from electric currents. Air flows across the hot coils, picking up the energy and becoming warmer. Then, this warm air is pumped through ducts around your home.

It’s important to note that auxiliary heat should only be used when necessary. It consumes more energy than the primary heating source and can raise your electricity bills. Set up a programmed thermostat to determine when to use this type of heat.

Regularly maintaining your HVAC system is necessary, especially during cooler months, so you don’t have to rely on auxiliary heat too often. Even auxiliary heat needs help sometimes, especially with extreme temperatures and HVAC malfunctions.

Factors Affecting Auxiliary Heat

To understand the factors affecting auxiliary heat, let me share with you some information about outside temperature and thermostat settings, as well as how heat is transferred from one area to another. 

These are crucial sub-sections that will offer you insights on how to maintain a comfortable temperature in your home despite weather changes and prevent higher energy bills from the overuse of auxiliary heat.

Outside Temperature and Thermostat Setting

Outdoor temp and thermostat settings have a big effect on auxiliary heat use. 

Low outside temperature and a high thermostat can mean more auxiliary heat, leading to higher energy use. Milder outside temp and lower thermostat settings may not need auxiliary heat at all.

Insulation, window efficiency, and house layout can also affect auxiliary heat use. Good insulation and windows reduce heat loss and cut down the need for auxiliary heat. Bigger, more open houses need more heating and so, more aux heat.

To reduce auxiliary heat and save energy, regularly maintain heating systems. Clean ducts, replace air filters and check for leaks or malfunctions. Keeping heating systems running well helps manage energy use.

Pro Tip: Invest in a programmable thermostat to save energy in winter and keep home comfy. Change settings based on time of day and temp changes!

Transfer Heat from One Area to Another

Transferring thermal energy from one region to another is affected by many things. Usually, heat goes from hotter to colder areas, changing the temperature difference. 

The speed and direction of this process depend on the medium it travels through. For instance, factors such as permeability and conductivity.

Airflow, humidity, and pressure also play a role in how heat moves around. These can slow down or speed up the rate of energy transfer. Even the external environment can affect how much heat is exchanged. On cold days, if the outside is still and dry, heat will escape faster from buildings than if it were windy or humid.

As an example, take a home with a broken thermostat. The auxiliary heating constantly turns on when not needed, resulting in higher bills. 

A technician discovers leaking vents are letting out heat before the rest of the house is warmed up. This makes the thermostat pump more energy than needed, without anyone noticing. Auxiliary heat is almost like extra warmth calling for help, only in this case, you pay for it.

When and Why to Use Auxiliary Heat

To ensure efficient heating in your home with a heat pump, it’s essential to use the right heating mode at the right time. 

In this section on “When and Why to use Auxiliary Heat,” we’ll cover the three main situations where you should activate the auxiliary heat on your thermostat. 

These include cases where the heat pump fails to produce enough heat, the temperature inside your home is too low, and there is a need for additional heating from a secondary heat source.

The heat Pump Cannot Produce Enough Heat

When the outdoor temperature drops, a heat pump may not produce enough heat for your home. Figure out why. It could be an undersized system. Then, you may need an extra source of heat. Electric resistance heaters and gas furnaces provide temporary heating. But they can drive up energy costs.

Operating an undersized system without auxiliary heat wears down the equipment. This leads to expensive repairs in the long run. Your HVAC system needs routine maintenance by a professional. This helps detect issues early and prolongs the life of the equipment.

Don’t let inadequate heating ruin your comfort in colder months. Contact a certified technician today. They’ll identify any underlying issues and explore solutions to improve efficiency. Proactive measures save money and prevent potential disasters.

Temperature Inside Your Home

Achieving a cozy atmosphere in your home can be tricky, especially during extreme weather. When the inside temperature drops below the set level, the heating system will start up. 

Depending on the system, you may also have auxiliary heat. This additional warmth is usually more powerful and energy-consuming than the main heat source and is designed to quickly lift indoor temperature.

When using auxiliary heat, make sure all windows and doors are closed tightly. Also, adjust or update the thermostat depending on outdoor temperatures. You may need a professional to assess your home’s insulation system for better energy efficiency and to minimize conflicts between main and auxiliary heat sources.

Not all homes have auxiliary heat, as it comes with added costs. But in regions with cold winters, having auxiliary heat could mean better comfort compared to using space heaters, which can be dangerous due to lack of power regulation. Auxiliary heat is like a secret lover and it only gets called upon when the primary fails.

Secondary Heat Source

Auxiliary heat is an alternative heating source that can either supplement or replace your main heating system. Essential if you experience cold weather conditions or power outages. It can prevent discomfort and property damage caused by freezing pipes or extreme temperatures.

Using auxiliary heat can also reduce energy costs. You can switch off your primary heating system and use a more efficient supplementary device. This lowers your utility bill and minimizes your carbon footprint.

It’s great for large households too. Makes sure warmth is evenly distributed throughout the house. Portable space heaters, electric blankets, and fireplaces are common examples of secondary heat sources.

It’s important to consult a professional technician or HVAC specialist before using any form of auxiliary heat. Improper installations and devices can lead to hazardous situations, such as carbon monoxide poisoning or fires.

U.S Energy Information Administration (EIA) states that households in the US consume approximately 21% of their total energy consumption towards space heating.

The Role of Thermostat in Auxiliary Heat

To manage your home’s heating system, you rely on your thermostat to communicate with your heat pump.

To ensure that you stay comfortable, your thermostat activates auxiliary heat when the temperature drops too low. 

Two important aspects of decision-making for your thermostat include understanding when it is necessary to turn on auxiliary heat and utilizing the auxiliary heat indicator on your thermostat to ensure you are using your system correctly.

Determining When to Activate Auxiliary Heat

Activating the auxiliary heat depends on many things. Indoor and outdoor temperature, desired indoor temperature, thermostat settings, and HVAC system type are all factors. Auxiliary heat usually turns on when primary heating can’t keep up.

To use backup heat efficiently and save money, better understanding of the factors that influence its activation is key. Homeowners should review these inputs often and make adjustments for significant cost savings.

Auxiliary Heat Indicator on Your Thermostat

The thermostat’s auxiliary heat indicator plays a major role in keeping indoor temperatures warm during cold weather. When the primary heating system fails, the thermostat triggers the auxiliary heat source, releasing extra heat and consuming more energy.

This indicator also helps monitor energy efficiency. If auxiliaries stay active for too long, this could mean maintenance or insulation problems. So, homeowners can lower energy bills by identifying areas that need repair.

Different thermostats have unique features that offer various auxiliary heat options. Some provide manual control to decide when and how much auxiliary power to use. Others depend on outdoor sensors to turn auxiliaries on automatically.

Thermostats have come a long way since the 1800s. Today, they include smart-home integration, and user-friendly interfaces that allow remote control through smartphone apps.

It’s important to understand the auxiliary heat indicator’s role. It supports backup plans and monitors energy usage, allowing homeowners to stay comfortable without breaking the bank.

Differences Between Auxiliary Heat and Emergency Heat

To understand the difference between auxiliary and emergency heat, let’s explore how these two heat sources work in your heat pump system. 

Using your source as emergency heat can lead to high energy costs, while air exchange and geothermal heat pumps offer more sustainable alternatives. In this section, we’ll take a closer look at these sub-sections to help you make an informed decision about which heat source is right for your home in case of emergency.

Auxiliary HeatEmergency Heat
What is it?Auxiliary heat is supplementary to the main heating system. It turns on when the primary system can’t keep up with the heating demand.Emergency heat is used when the primary heating system fails entirely. It’s a secondary heating system designed to be used temporarily until the primary system is fixed.
Energy ConsumptionModerate. It’s designed to support the primary heating source, and therefore, doesn’t consume as much energy as the emergency heat.High. It consumes more energy as it’s designed to replace the primary heating system when it fails.
CostRelatively less costly due to moderate energy consumption.Potentially high cost if used for extended periods due to its high energy consumption.
When to use?When the primary heat source cannot maintain the desired temperature and needs additional help.Only to be used when the primary heating system fails completely.
Manual/Automatic switchThe switch can be done either manually or automatically depending on the system setup.Usually requires manual switching.
Impact on comfortHelps in maintaining comfortable temperature when the primary system is not sufficient.Ensures the temperature doesn’t drop to uncomfortable or dangerous levels when the primary system fails.

How to Manage Auxiliary Heat

To manage your heat pump’s auxiliary heat, turn off the auxiliary heat when it’s not required to save energy costs, Learn how to set your thermostat correctly to keep your home at a comfortable temperature without overworking the auxiliary heat. You may find these useful tips helpful in managing your aux heat and saving money on electricity bills.

Turn Off the Aux Heat

Maximizing your home heating? Here’s some tips to manage your auxiliary heat.

  1. Program your thermostat – Align the temperature with your routine. Lower when not home, higher when you are.
  2. Check the filter – Clean or replace regularly for optimal air flow and reduced usage.
  3. Eliminate drafts – Check doors and windows and seal them up. Retain warmth without auxiliary heat.
  4. Insulation – Check attics, walls and flooring for sufficient insulation. This will reduce heat loss and increase efficiency.

Talk to an HVAC pro to tailor these tips to your home’s needs!

29% of energy used in US households is for heating according to the EIA. So, don’t be afraid to get cozy.

Setting Your Thermostat Correctly

The ideal room temperature is between 68°F and 72°F. This range keeps you comfortable and saves energy. 

Setting your thermostat schedule according to your daily routine could save up to 10% on yearly heating bills. 

Thermostats can read temperatures differently in various spots. Avoid placing near drafts, wall sockets or sunlight as these may make readings incorrect and cause energy waste. Smart thermostats provide automated scheduling for easy, efficient management.

A traveller on vacation forgot to adjust her thermostat, returning home to a sky-high bill. Adjusting your thermostat accurately could prevent such problems. 

Troubleshooting Issues and It’s Solutions Regarding Auxiliary Heat

To troubleshoot your auxiliary heat, with the focus on stopping auxiliary heat from coming and performing heat pump repair effectively, you may need to examine the thermostat settings, outdoor temperature, and the heat source

In this section, we’ll provide tips on how to ensure that your auxiliary heat is still operating effectively and how to stop it from turning on unnecessarily

Additionally, we’ll cover some common heat pump repair strategies that could address any issues that arise in the auxiliary heating system.

Common IssueCausesSolution
Auxiliary Heat Coming On Too OftenInefficient primary heating system,improper thermostat settings, clogged air filters,leaks in ductwork,uneven room temperatures, poor insulation.Check and adjust thermostat settings,replace clogged air filters, seal any leaks in ductwork, balance ventilation for consistent room temperatures, use curtains/window shades to improve insulation. Consult with an HVAC professional if needed. A programmable thermostat can also improve the overall heating system’s efficiency.
Heat Pump Not Heating ProperlyIncorrect thermostat settings, dirty filters or fan blades, disrupted airflow,refrigerant leaks.Check thermostat settings, ensure filters and fan blades are clean to maintain proper airflow and heat exchange. For power issues or refrigerant leaks, professional help may be necessary.
High Running Costs of Heat PumpThe inefficient operation, excessive use of auxiliary heat, and improper scheduling.The inefficient operation, excessive use of auxiliary heat,improper scheduling.


Winter is coming. Heat pumps help to keep your home warm. But in freezing temperatures, they may not be enough. This is where auxiliary heat comes in. It can add extra warmth to keep you and your family comfortable. Auxiliary heat turns on when the temperature inside your home drops below the thermostat setting. It can be electric resistance heating strips or another secondary heating source. Having a backup source is important. It helps if the primary source can’t produce enough energy. Sometimes the main source fails and needs repairs. Waiting for technicians to fix it can be risky. That’s why having an emergency plan with a secondary source is useful. In conclusion, having aux heat is essential during winter. Make sure you have a suitable backup before winter arrives. That way, your comfort is secure no matter what weather winter brings.

Frequently Asked Questions

What is auxiliary heat on a heat pump?

Auxiliary heat, also called aux heat, is an additional heating system in a heat pump. When the outside temperature drops below the heat pump’s optimal range, auxiliary heat will kick in to keep your home warm.

How does auxiliary heat work with a thermostat?

When the thermostat in your home calls for heat and the heat pump can’t produce enough heat, the thermostat will automatically turn on the auxiliary heat. This is an essential backup heat source to keep your home warm.

What is the difference between auxiliary heat and emergency heat on a heat pump?

Auxiliary heat is a secondary heating source that kicks in when the heat pump cannot keep up with the desired temperature. On the other hand, emergency heat is a manual setting that turns on the backup heating system when the heat pump cannot operate at all.

How can I stop the auxiliary heat from coming on too often?

One way to stop auxiliary heat from coming on too often is to set your thermostat to a lower temperature. This way, the heat pump will work longer and harder to keep your home warm before turning on the auxiliary heat.

Is it necessary to have an auxiliary heating system in a heat pump?

Yes, auxiliary heat is an essential backup heating source to keep your home warm in case the heat pump cannot operate efficiently. It is especially important during colder temperatures when the heat pump may struggle to produce enough heat.

How does the heat pump transfer heat between the inside and outside of a home?

Heat pumps transfer heat from one area to another through air exchange or the use of geothermal heat pumps. The system works by extracting heat from the outside air or ground and transferring it to the inside of your home using a refrigerant.

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