What Is Emergency Heat Setting on Thermostat and Why Should You Use It for Home Safety?

What Is Emergency Heat Setting on Thermostat?

The emergency heat setting on a thermostat is a backup heating system that is used when the primary heat fails in keeping the house warm.

It is often found in homes with a heat pump as well as a gas, oil, electric, or hot-water backup system.

This setting is activated automatically when the temperature dips too low and works with the primary heating system.

It should only be used temporarily until the heating system can be fixed, as emergency heat is more expensive to run than using the heat pump alone.

It is recommended to avoid using emergency heat unless necessary and to call a heating technician for maintenance and repairs.

Key Points:

  • Emergency heat setting on thermostat is a backup heating system
  • Common in homes with a heat pump and backup system
  • Activated automatically when temperature drops too low
  • Should only be used temporarily until primary heating system is fixed
  • More expensive to run than heat pump alone
  • Recommended to call technician for maintenance and repairs instead

Did You Know?

1. The emergency heat setting on a thermostat is a backup option that activates when your primary heating system malfunctions or cannot keep up with the desired temperature. It ensures that you have a source of heat in case of emergency.

2. Emergency heat is usually fueled by electric resistance heating. This means that it uses electric coils to generate heat instead of relying on a gas or oil furnace. It can be an energy-intensive option compared to your primary heating system.

3. The emergency heat setting is particularly useful in extremely cold weather conditions when your primary heating system may struggle to maintain a comfortable temperature. It provides an immediate and powerful source of heat to warm your home rapidly.

4. In some cases, the emergency heat setting is referred to as “auxiliary heat” or “back-up heat” on thermostats. The terms can be used interchangeably and serve the same purpose.

5. It is important to remember that the emergency heat setting should only be used when necessary, such as during malfunctioning of your primary heating system or during extremely cold temperatures. Relying on emergency heat for prolonged periods can lead to higher energy consumption and increased utility expenses. Therefore, it is advisable to have your primary heating system inspected and repaired as soon as possible when it encounters issues.

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What Is Emergency Heat Setting?

The emergency heat setting is a common feature in heat pump systems. It serves as an alternative heating source when the heat pump is unable to effectively warm the home. By activating a secondary heating system, like a furnace, it generates more heat than the heat pump alone. The emergency heat setting can be manually enabled or disabled based on the thermostat’s configuration.

How Does Emergency Heat Setting Work?

When the temperature outside drops below 35° Fahrenheit, the heat pump may struggle to extract enough heat from the outdoor air to warm the house. In such cases, the emergency heat setting is triggered. This setting allows the secondary heating system, usually located indoors, to take over and provide the necessary warmth.

The activation of the emergency heat setting can occur automatically when the heat pump detects the temperature has reached the predefined threshold. Additionally, homeowners have the option to manually turn on the emergency heat when they feel the heat pump alone is insufficient to meet their heating needs.

When To Use Emergency Heat Setting?

Emergency heat should only be used when the heat pump is unable to warm the home adequately. For example, if the heat pump is malfunctioning, frozen, or broken, activating the emergency heat setting can provide a temporary solution to maintain a comfortable temperature indoors. It is crucial to note that the emergency heat setting is not intended for regular use or to replace proper maintenance and repairs of the heat pump system.

Homeowners should avoid relying on emergency heat unless it is absolutely necessary. Regular usage of the emergency heat setting can significantly increase energy consumption and lead to higher heating bills. Instead, if the heat pump is not functioning properly, it is recommended to contact a heating technician for maintenance and repairs.

Pros And Cons Of Emergency Heat Setting

The emergency heat setting offers some benefits, but it also comes with certain drawbacks. Understanding the pros and cons can help homeowners make informed decisions when using this feature.


  • Provides a backup heating source when the heat pump is unable to meet heating demands.
  • Ensures the home remains warm and comfortable during emergencies, such as heat pump malfunctions or extreme weather conditions.
  • Can be manually activated or automatically triggered, depending on the thermostat’s configuration.
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  • Emergency heat is more expensive to run than using the heat pump alone, which can result in higher energy bills.
  • Reliance on emergency heat can indicate an underlying issue with the heat pump that requires maintenance or repairs.
  • Continuous use of the emergency heat setting can put additional strain on the secondary heating system, potentially leading to increased wear and tear.

Understanding The “Em Heat” Setting

The “EM heat” setting is commonly found on thermostats and is an abbreviation for emergency heat. This setting serves as a backup heating system when the primary heating source fails to maintain a comfortable indoor temperature. It is particularly useful in homes that have a heat pump, paired with a secondary heating system such as a gas furnace, electric heat strip, oil, or hot-water system.

This feature activates the secondary heating system, ensuring that the indoor temperature remains cozy even when the primary heating source is unable to perform effectively.

Key points:

  • “EM heat” stands for emergency heat
  • Activates the backup heating system
  • Used when the primary heating source fails
  • Commonly found in homes with a heat pump and secondary heating system

Please note that the use of the “EM heat” setting should be limited to emergency situations and not relied upon as a primary heating solution.

Tips And Recommendations For Emergency Heat Setting

Here are some tips and recommendations to keep in mind when using the emergency heat setting on your thermostat:

  1. Limit the use of emergency heat to genuine emergencies, such as a malfunctioning heat pump or extreme weather conditions.
  2. Regularly maintain and service your heat pump to reduce the need for emergency heat activation.
  3. If you need to use emergency heat, monitor your energy consumption and be prepared for higher heating bills.
  4. Contact a qualified heating technician if your heat pump is not functioning correctly or if you are experiencing frequent emergency heat activations.
  5. Seek professional advice to determine the appropriate temperature threshold for emergency heat activation based on your climate and heating system.

By understanding the emergency heat setting and its purpose, homeowners can better utilize this feature for their safety and comfort, while also minimizing energy usage and expenses.

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Frequently Asked Questions

When should I use emergency heat on my thermostat?

Emergency heat should be used on your thermostat when the outside temperature drops below the range of 30 to 35 degrees Fahrenheit. This setting enables an alternate heat source to be activated, allowing your home to stay warm even when the normal heating system is unable to pull in and heat the air effectively. Using emergency heat in such extreme cold conditions ensures that your home remains comfortable and prevents the risk of pipes freezing or other weather-related issues.

What happens when you put your thermostat on emergency heat?

When you switch your thermostat to emergency heat, your system essentially disregards the heat pump and relies solely on the backup element. While this may provide heat in emergency situations where the main heat source is not functioning, it should be used sparingly due to the strain it puts on the backup element. This component is designed to handle extreme circumstances for brief periods of time, so continuous use of emergency heat can potentially lead to excessive wear and tear on the system. Therefore, it is important to exercise caution and only utilize emergency heat when necessary.

Is it OK to run emergency heat?

No, it is not advisable to run emergency heat unless your regular heating system fails. Using emergency heat mode unnecessarily will significantly increase your energy bills. Therefore, it is important to only resort to emergency heat when your primary heating method is no longer functioning effectively in heating your home.

Why is it called emergency heat?

Emergency heat is referred to as such because it serves as a backup solution when the primary heat pump system is not functioning properly. It is called “emergency” heat because it is used as a last resort in situations where the regular heating system has failed or is unable to adequately warm the home. This alternative electric heating mode, although essentially the same as the auxiliary element, is activated in a different configuration to provide immediate and temporary heat, ensuring the homeowner’s comfort during unexpected system failures.

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