What Is Emergency Heat on Thermostat? – Revealing Its Vital Role

Welcome to a comprehensive exploration of an important feature in modern thermostats “Emergency Heat.” As the winter chill settles in, understanding how this function works can make all the difference in keeping your home warm and cozy.

In this guide, we’ll uncover what is emergency heat on thermostats and the secrets behind emergency heat, focusing on its purpose, operation, and when it’s best to use it.

Whether you’re an experienced homeowner or a newbie to thermostat technology, Let’s begin on this journey to the world of emergency heat and learn how to manage it effectively for optimal comfort and energy efficiency.

What is Primary Heating System on Thermostat?

At the heart of your home’s heating infrastructure is the primary heating system. This system is responsible for generating and distributing heat throughout your living space, ensuring a cozy environment when the temperature drops. 

The primary heating system can vary based on the type of energy source used and the heating mechanism employed. Some common types of primary heating systems include:


Furnaces use gas, oil, or electricity to produce heat. They operate by heating air and then distributing it through ductwork to various rooms in your home.


Boilers heat water, which is then circulated through radiators, baseboard heaters, or underfloor pipes to warm your home.

Heat Pumps

Heat pumps extract heat from the outside air or ground and transfer it indoors. They can both heat and cool your home, making them versatile systems.

Electric Resistance Heaters

These heaters directly convert electrical energy into heat, making them common in areas with milder climates or as supplemental heating.

Each primary heating system has its advantages and limitations, and homeowners choose the system that best suits their needs, local climate, and energy preferences. 

While these systems are designed to effectively heat your home, they can face challenges during extreme weather conditions, system malfunctions, or maintenance issues. 

This is where the concept of Emergency Heat comes into play, providing an extra layer of comfort and protection during such situations.

What is Emergency Heat on Thermostat?

In the world of thermostat operation, Emergency Heat serves as a reliable backup plan when your primary heating system encounters difficulties. It’s like a safety net that ensures your home remains warm, even in adverse conditions. But what exactly is Emergency Heat, and why does it matter?

Emergency Heat, often referred to as “auxiliary heat,” is a feature found on many modern thermostats. It’s designed to activate an alternative heating source when the primary heating system struggles to maintain the desired indoor temperature. 

This alternative source of heat can include electric resistance heating elements, which can provide rapid and powerful heating in case of emergencies.

The term “emergency” doesn’t necessarily imply that your primary heating system has completely failed. Instead, it covers scenarios where the primary system may not be able to keep up with the demand due to extremely cold weather, maintenance issues, or other factors. 

Emergency Heat ensures that your home remains warm and comfortable when you need it most.

To put it simply, Emergency Heat is your thermostat’s way of saying, “I’ve got you covered” when standard heating methods might not be sufficient. It’s a feature that provides peace of mind during chilly winter nights and unexpected heating system glitches. 

As we delve deeper, we’ll explore how Emergency Heat works, when to use it, and how to optimize its benefits while being mindful of energy consumption.

When Is Emergency Heat Used on Thermostat?

Emergency Heat on a thermostat comes into play during specific situations when your primary heating system faces challenges in maintaining a comfortable indoor temperature. 

While it’s not an everyday feature, knowing when to activate Emergency Heat can be crucial for ensuring your home remains warm and cozy. Here are some scenarios where using Emergency Heat might be necessary:

Extreme Cold Weather

During exceptionally cold weather conditions, your primary heating system might struggle to keep up with the demand for warmth. Emergency Heat can be engaged to provide an extra boost of heat and ensure your home remains comfortable even in the face of frigid temperatures.

Primary Heating System Malfunction

If your primary heating system experiences a malfunction or requires repairs, Emergency Heat can act as a temporary solution to keep your home warm while you address the issue.

Heat Pump Defrost Cycle

Heat pumps can occasionally enter defrost cycles during colder weather to prevent frost buildup on the outdoor unit. During this cycle, the heat pump briefly switches to cooling mode, which can lead to a temporary drop in indoor temperature. 

Activating Emergency Heat during the defrost cycle ensures that your home remains warm during this period.

Vacation or Extended Absence

If you’re away from home for an extended period and have set your thermostat to a lower temperature to save energy, activating Emergency Heat can help maintain a comfortable temperature in your absence.

Primary System Maintenance

When performing routine maintenance or repairs on your primary heating system, Emergency Heat can provide a backup source of warmth for your home while the main system is temporarily unavailable.

How EM Heat Works on Thermostat?

“EM heat” or Emergency Heat operates as a secondary heating source that kicks in when your primary heating system struggles to maintain the desired indoor temperature. It’s designed to provide a reliable and efficient solution to keep your home warm during challenging situations. Let’s take a closer look at how Emergency Heat works:

Thermostat Detection

Your thermostat is equipped with sensors that monitor both indoor and outdoor temperatures. When the indoor temperature drops significantly below your set comfort level or when your primary heating system is unable to keep up, the thermostat recognizes the need for additional heating.

Activation of Emergency Heat

Once the thermostat detects that the primary heating system isn’t meeting the demand, it triggers the activation of Emergency Heat. This can involve turning on electric resistance heating elements that generate heat quickly and effectively.

Rapid Heating

Electric resistance heating elements are known for their ability to provide almost instant heat. When Emergency Heat is engaged, these elements start producing warmth immediately, raising the indoor temperature to your desired level.

Maintaining Comfort

While Emergency Heat is active, it ensures that your home remains at a comfortable temperature, even in the face of harsh weather conditions or primary heating system issues.

Energy Considerations

It’s important to note that while Emergency Heat is a reliable solution, it can be energy-intensive. Electric resistance heating tends to consume more energy compared to other heating methods. As such, it’s recommended to use Emergency Heat judiciously and consider it a temporary solution until the primary heating system is back to optimal operation.

How to Identify EM Heat on Thermostat?

Recognizing when em heat is active on your thermostat is essential for understanding your heating system’s status and ensuring effective usage. While different thermostats may have slightly varying indicators, there are common ways to identify when Emergency Heat is engaged:

Display Indicators

Many thermostats have a display screen that shows relevant information. When Emergency Heat is active, you might see a clear indicator on the screen, such as the term “Emergency Heat” or an icon that signifies its activation.

Temperature Setpoint

If you notice that the indoor temperature displayed on the thermostat is rising faster than usual or is significantly higher than your set temperature, it could be an indication that Emergency Heat is providing additional heating.

Auxiliary Heat Indicator

Some thermostats use the term “Auxiliary Heat” to refer to Emergency Heat. If you see this label or indicator, it means that the secondary heating source is in operation.

Heating Element Noise

Electric resistance heating elements can produce a distinct sound when they’re active. If you hear a noise similar to a low hum or a fan-like sound coming from your heating system, it might indicate that Emergency Heat is in use.

Consulting the Manual

If you’re unsure about how to identify Emergency Heat on your specific thermostat model, refer to the user manual. It should provide information about indicators, symbols, or messages related to the activation of Emergency Heat.

7 Benefits of Using Emergency Heat on Thermostat

Emergency Heat on a thermostat offers several key benefits that can enhance your comfort and peace of mind, particularly during challenging situations. Understanding these advantages can help you make the most of this feature while ensuring the well-being of your home and loved ones:

Reliable Heat Source

When your primary heating system encounters difficulties, Emergency Heat serves as a dependable backup source of warmth. It ensures that your home remains comfortable even in extreme weather conditions or during system malfunctions.

Quick Response

Electric resistance heating elements, often used for Emergency Heat, generate heat rapidly. This quick response can help raise the indoor temperature to your desired level swiftly, preventing discomfort due to chilly conditions.

Consistent Comfort

By activating Emergency Heat, you’re ensuring that your home’s temperature remains stable and consistent. This is especially crucial during cold spells when maintaining a comfortable environment is essential for well-being.

Peace of Mind

Knowing that you have a backup plan in the form of Emergency Heat can offer peace of mind. You can rest assured that your home will stay warm even if unexpected issues arise with your primary heating system.

Temporary Solution

Emergency Heat serves as a temporary solution until the underlying problems with your primary heating system are addressed. It allows you time to schedule repairs or maintenance without compromising your immediate comfort.

Protection for Your Home

Keeping your home at a reasonable temperature, even when the primary heating system struggles, can help prevent issues like frozen pipes or damage to sensitive materials that are sensitive to temperature fluctuations.


Emergency Heat provides flexibility in managing your home’s heating needs. You can activate it when necessary and deactivate it when your primary heating system is back to full functionality.

Potential Drawbacks of Emergency Heat on Thermostat

While Emergency Heat serves as a valuable tool for maintaining indoor comfort during challenging times, it’s essential to be aware of its potential drawbacks. Being mindful of these drawbacks can help you use Emergency Heat more effectively and make informed decisions about when to activate it:

Energy Consumption

Electric resistance heating elements, commonly used in Emergency Heat, can consume more energy compared to other heating methods. 

Relying heavily on Emergency Heat without addressing the underlying issues with your primary heating system can lead to increased energy bills.

Higher Operating Costs

As Emergency Heat utilizes energy-intensive heating elements, using it extensively can result in higher operating costs. 

It’s recommended to explore other solutions, such as addressing maintenance issues promptly, to reduce the need for Emergency Heat.

Environmental Impact

Increased energy consumption associated with Emergency Heat contributes to a larger carbon footprint. Using it sparingly and efficiently can help mitigate its environmental impact.

Potential Overuse

It’s important to avoid using Emergency Heat as a long-term solution. Depending on it extensively can delay necessary repairs or maintenance for your primary heating system, leading to increased costs and energy waste.

Limited Availability

Some homes might not have Emergency Heat capability, especially in regions where extreme cold weather is less common. In such cases, relying solely on the primary heating system’s functionality becomes crucial.

Lack of Detection

In certain cases, the thermostat might not accurately detect the need for Emergency Heat, leading to its unnecessary activation. Regular thermostat maintenance and calibration can help mitigate this issue.

Additional Tips for Using Emergency Heat Wisely on Thermostat

Using Emergency Heat judiciously can help you maintain indoor comfort without excessively driving up energy consumption. Here are some practical tips to ensure you make the most of this feature while being mindful of energy usage:

Address Underlying Issues

Instead of solely relying on Emergency Heat, address the root causes of why your primary heating system isn’t functioning optimally. Regular maintenance and timely repairs can reduce the need for Emergency Heat.

Activate Temporarily

Use Emergency Heat as a temporary solution while you work on resolving primary heating system problems. Once the primary system is back in proper working condition, switch back to it to minimize energy usage.

Adjust Temperature Settings

If you activate Emergency Heat, consider adjusting your thermostat’s temperature settings to slightly lower than usual. This can help reduce energy consumption while still providing adequate warmth.

Limit Usage During Milder Weather

Reserve Emergency Heat for extreme cold weather situations, and rely on your primary heating system during milder temperatures to avoid unnecessary energy expenditure.

Programmable Thermostats

If you have a programmable thermostat, set schedules that optimize energy efficiency. During periods when you’re away or sleeping, adjust the temperature to reduce the reliance on Emergency Heat.

Regular Maintenance

Ensure your heating systems are well-maintained and serviced to prevent emergencies that trigger the use of Emergency Heat. Regular check-ups by professionals can catch potential issues before they escalate.

Insulation and Sealing

Proper insulation and sealing of your home can help retain heat better, reducing the need for Emergency Heat even during colder weather.

Monitor Weather Forecasts

Keep an eye on weather forecasts to anticipate colder spells. Preemptively adjusting your thermostat settings can help your primary heating system better handle temperature drops.

Energy-Efficient Appliances

Consider upgrading to energy-efficient heating systems or appliances that can help reduce energy consumption during colder periods.

Educate Household Members

Ensure everyone in your household understands the purpose and operation of Emergency Heat. This can help prevent unnecessary activation and overuse.

Preventive Measures for EM Heat on Thermostats

Preventing the need for Emergency Heat begins with proactive measures aimed at maintaining the optimal functioning of your primary heating system. By taking preventive steps, you can reduce the likelihood of encountering situations that require the activation of Emergency Heat. Here are some preventive measures to consider:

Regular Maintenance

Schedule routine maintenance for your primary heating system. Professional inspections can identify potential issues before they escalate, minimizing the risk of sudden breakdowns.

Replace Filters

Clean or replace filters regularly to ensure efficient airflow and prevent strain on your heating system. Clogged filters can lead to reduced performance and increased energy consumption.

Clean Vents and Ducts

Ensure that air vents, registers, and ducts are clean and unobstructed. This promotes even heating distribution and helps your system operate smoothly.

Check Thermostat Batteries

If your thermostat uses batteries, regularly check and replace them. A malfunctioning thermostat can lead to inaccurate temperature readings and inefficient heating.

Seal Leaks

Inspect your home for drafts and seal any gaps or leaks around windows, doors, and other openings. Proper insulation prevents heat loss and reduces the workload on your heating system.

Monitor for Unusual Sounds

Pay attention to any unusual sounds coming from your heating system. Clanking, rattling, or other noises can indicate potential issues that require prompt attention.

Adjust Thermostat Settings

During milder weather, adjust your thermostat settings to lower temperatures to reduce the strain on your heating system. Use programmable thermostats to set energy-efficient schedules.

Emergency Heat Testing

Periodically test Emergency Heat to ensure it’s functioning correctly. This practice can help you identify any issues with the backup heating system before they become critical.

Upgrade Aging Systems

If your primary heating system is outdated and prone to frequent malfunctions, consider upgrading to a more energy-efficient model. Newer systems are often more reliable and cost-effective in the long run.

Frequently Asked Questions (FAQ’s)

Is Emergency Heat energy-efficient?

Emergency Heat is effective but can be energy-intensive due to the use of electric resistance heating. While it’s a reliable backup, using it wisely and addressing primary heating system issues promptly helps optimize energy efficiency.

Can Emergency Heat be used for an extended period?

While Emergency Heat can provide warmth in emergencies, it’s not designed for prolonged use. Relying on it excessively can lead to increased energy consumption and higher utility bills. Focus on resolving primary system issues for long-term comfort.

How can I identify when Emergency Heat is active on my thermostat?

Look for display indicators, terms like “Emergency Heat” or “Auxiliary Heat” changes in temperature setpoints or distinctive heating element noises. Your thermostat’s user manual can provide specific details for your model.

Can I prevent the need for Emergency Heat activation?

Yes, by taking preventive measures such as regular maintenance, addressing system issues promptly, sealing leaks, and using energy-efficient practices, you can reduce the likelihood of relying on Emergency Heat.


In the realm of home heating and comfort, Emergency Heat on a thermostat stands as a reliable guardian against the chill of extreme weather and unexpected system challenges. This feature, often referred to as auxiliary heat, steps in to ensure your living space remains warm and inviting even in the face of adversity.

Remember that EM Heat is a temporary solution. Regular maintenance, preventive measures, and professional inspections contribute to the efficient functioning of your primary heating system. 

As you navigate the intricacies of thermostat operation and heating systems, armed with a clear understanding of Emergency Heat, you’re better equipped to maintain comfort and coziness within your living space, even in the harshest of conditions.

Scott Maupin