At DuctOwl.com, one of the most common points of confusion we see is the difference between EM Heat and regular Heat on a thermostat. They are not interchangeable, and understanding when each setting should be used can help homeowners avoid higher energy costs, unnecessary system strain, and inconsistent indoor comfort. In this guide, we break down the difference with clear, practical insight so you can make smarter thermostat decisions and better protect your heat pump system.
TL;DR Quick Answer
EM Heat vs Heat on a Thermostat: What Homeowners Actually Need to Know
Heat is the normal setting for a heat pump system. It runs the system as designed for everyday heating efficiency.
EM Heat means Emergency Heat. It switches your system to backup heat only and usually shuts off the outdoor heat pump unit.
What homeowners should know:
- Use Heat for daily heating
- Use EM Heat only if the heat pump is not working properly
- EM Heat usually costs more to run
- Leaving EM Heat on unnecessarily can raise energy bills
At DuctOwl.com, our practical view is simple: if your home is heating normally, keep the thermostat on Heat. Save EM Heat for system trouble, freezing conditions, or when your HVAC technician tells you to use it.
Top Takeaways
- Heat is the standard setting.
- It is best for everyday heating.
- It is usually the most efficient option.
- EM Heat means Emergency Heat.
- It uses backup heat only.
- It is not meant for normal daily use.
- Use Heat when your heat pump is working normally.
- Use EM Heat only during system trouble or if a technician recommends it.
- Avoid leaving EM Heat on longer than needed.
- EM Heat can raise energy costs.
- It may also put unnecessary strain on your system.
- Knowing the difference helps you:
- protect comfort
- improve efficiency
- avoid avoidable HVAC issues
Table of Contents
EM Heat vs Heat on a Thermostat
For most homeowners, the difference between EM Heat and regular Heat comes down to normal operation versus backup operation. The Heat setting is what your thermostat should use for everyday comfort. In this mode, your heat pump runs as designed, pulling heat from outside air and moving it indoors as efficiently as possible. It is the standard setting for routine heating and usually the most cost-effective choice.
EM Heat, or Emergency Heat, is different. It tells the system to rely on the backup heat source instead of the heat pump. This setting is typically used only when the heat pump is not working properly, the outdoor unit is iced over, or a technician recommends switching to backup heat during a problem. Because backup heat often uses more energy, leaving EM Heat on when it is not needed can lead to higher utility bills.
Homeowners do not usually need to switch to EM Heat during normal cold weather if the heat pump is operating correctly. In most cases, the thermostat should stay on Heat and let the system manage heating the way it was designed to. Understanding this difference helps prevent confusion, avoids unnecessary energy costs, and supports better overall HVAC performance.
Bottom Line
Use Heat for normal daily heating. Use EM Heat only when your heat pump cannot operate properly or when an HVAC professional advises it. For most homes, knowing when not to use EM Heat is just as important as knowing what it means.
“At DuctOwl.com, we often find that homeowners assume EM Heat is just a stronger version of regular Heat, but in real-world HVAC use, it is a backup setting that should be used with care. From our perspective, the smartest approach is to keep your thermostat on Heat for normal operation and treat EM Heat as a temporary solution when the heat pump cannot do its job efficiently.”
Essential Resources
At DuctOwl.com, we prefer resources that help homeowners make smarter thermostat decisions without sending them down a rabbit hole of mixed advice. The list below leans on official thermostat support pages, government guidance, and energy-efficiency resources so readers can move from confusion to clarity with confidence.
1. Google Nest Help: Get a Clear Definition of Emergency Heat
This is one of the best starting points for homeowners with a heat pump. It explains that Emergency Heat is a backup mode, not your normal heating setting, and helps clarify when the option appears on compatible thermostats.
URL: https://support.google.com/googlenest/answer/9276120?hl=en
2. Google Nest Help: Understand Why Backup Heat Should Be Used Carefully
This resource adds important context around efficiency and thermostat behavior, which matters when comparing EM Heat with regular Heat. It is especially useful for readers trying to understand why backup heat can be more expensive and why thermostats try to manage it carefully.
URL: https://support.google.com/googlenest/answer/9244728?hl=en
3. Honeywell Home Support: Learn What the EM HT Switch Means
If your thermostat actually shows EM HT, this manufacturer support page gives a direct explanation of what that setting means and why it is typically used only until the heat pump issue can be addressed. From a homeowner standpoint, it helps turn a confusing label into a practical next step.
URL: https://www.honeywellhome.com/blogs/support/prestige-hd-7-day-programmable-thermostat-4
4. ecobee Support: See How Auxiliary Heat Is Controlled in Real Life
One of the biggest points of confusion we see is the difference between Aux Heat and EM Heat. ecobee’s threshold settings page is valuable because it shows how smart thermostats manage auxiliary heat automatically, which helps readers better understand what regular Heat mode is doing behind the scenes.
URL: https://support.ecobee.com/s/articles/Threshold-settings-for-ecobee-thermostats
5. U.S. Department of Energy: Understand How Heat Pumps Work Before Comparing Settings
Before deciding when EM Heat makes sense, it helps to understand how a heat pump system is supposed to heat a home in the first place. This Department of Energy guide gives homeowners a reliable foundation for understanding normal heat pump operation and energy efficiency.
URL: https://www.energy.gov/energysaver/heat-pump-systems
6. U.S. Department of Energy: Put EM Heat in the Bigger Home-Heating Picture
This resource is helpful for readers who want a broader view of heating costs, comfort, and system efficiency. At DuctOwl.com, we like this kind of source because it helps homeowners make better decisions beyond just one thermostat setting.
URL: https://www.energy.gov/energysaver/home-heating-systems
7. ENERGY STAR: Compare Heat Pump Efficiency and Long-Term Operating Value
For homeowners thinking beyond thermostat labels, this ENERGY STAR resource is a strong next read. It helps connect the EM Heat vs Heat conversation to overall energy performance, equipment quality, and money-saving potential.
URL: https://www.energystar.gov/products/air_source_heat_pumps
Bottom Line
From the DuctOwl.com perspective, the best next resources are the ones that help homeowners understand what EM Heat is, how it differs from normal Heat, how thermostats manage backup heat, and why efficiency matters before switching settings. These seven sources do that with a strong mix of official product guidance and U.S. energy-efficiency information.
Supporting Statistics
At DuctOwl.com, we believe the numbers should help homeowners make smarter thermostat decisions. These statistics show why Heat is usually the right everyday setting and why EM Heat should be used with care.
Key Supporting Stats
1. Heat pumps can cut heating electricity use by about 50%.
- The U.S. Department of Energy says modern air-source heat pumps can reduce electricity use for heating by about 50% compared with electric resistance heating.
- This helps explain why normal Heat mode is usually the more efficient choice.
- Source: U.S. Department of Energy
- URL: https://www.energy.gov/energysaver/air-source-heat-pumps
2. Heat pumps can deliver 2 to 4 times more heat energy than the electricity they use.
- DOE states that a properly installed air-source heat pump can deliver 2 to 4 times more heat energy than the electricity it consumes.
- That efficiency is a major reason homeowners should not treat EM Heat as a better everyday option.
- Source: U.S. Department of Energy
- URL: https://www.energy.gov/energysaver/air-source-heat-pumps
3. Backup heat misuse is a known efficiency issue.
- DOE notes that energy codes require controls to prevent unnecessary electric resistance backup heat operation.
- DOE also identifies this as one of the most commonly violated heat pump installation practices.
- In simple terms, unnecessary backup heat can waste energy and reduce system efficiency.
- Source: U.S. Department of Energy
- URL: https://www.energy.gov/energysaver/air-source-heat-pumps
4. Many homes do not need emergency-style heating above 40°F.
- DOE explains that a home’s heating balance point is usually well below 40°F in code-built homes.
- That means cold weather alone does not automatically justify switching to EM Heat.
- Source: U.S. Department of Energy
- URL: https://www.energy.gov/energysaver/air-source-heat-pumps
5. Americans spend about 90% of their time indoors.
- EPA reports that Americans spend roughly 90% of their time indoors.
- That makes heating decisions more important because they affect comfort where people spend most of their lives.
- Source: U.S. Environmental Protection Agency
- URL: https://www.epa.gov/report-environment/indoor-air-quality
6. Indoor pollutant levels can be 2 to 5 times higher than outdoor levels.
- EPA says some indoor pollutant levels are often 2 to 5 times higher than typical outdoor levels.
- Efficient, steady heating supports a healthier and more comfortable indoor environment.
- Source: U.S. Environmental Protection Agency
- URL: https://www.epa.gov/report-environment/indoor-air-quality
What These Statistics Mean
- Heat is usually the best setting for everyday efficiency.
- EM Heat is a backup option, not a daily-use mode.
- Using the wrong setting can:
- increase energy costs
- reduce system efficiency
- affect indoor comfort
Bottom Line
The data supports a simple takeaway:
- Use Heat for normal daily heating.
- Use EM Heat only when the heat pump cannot operate properly or when a professional recommends it.
- For most homeowners, the smartest move is to protect the efficiency advantage their heat pump is designed to deliver.
Final Thought & Opinion
The difference between EM Heat and Heat is simple.
- Heat is for normal daily use.
- EM Heat is a backup setting for specific system problems.
For most homeowners, Heat is the right choice. It lets the heat pump work the way it was designed to work.
A Practical Opinion From DuctOwl.com
At DuctOwl.com, we believe one of the most common mistakes homeowners make is thinking EM Heat is a stronger or better version of regular heat.
It is not.
In real-world use, turning on EM Heat too soon can:
- raise energy bills
- reduce efficiency
- put unnecessary strain on the system
What Homeowners Should Remember
- Leave the thermostat on Heat when the system is working normally.
- Use EM Heat only when the heat pump is not operating properly.
- Treat EM Heat as a temporary backup, not a comfort upgrade.
Bottom Line
The smartest approach is usually the simplest one:
- Use Heat for everyday heating.
- Use EM Heat only when needed.
- Let the system do its job unless there is a clear problem.
That mindset helps protect:
- comfort
- energy efficiency
- long-term HVAC performance
FAQ on “em heat vs heat”
Q: What is the difference between EM Heat and Heat?
A:
- Heat = normal daily heating mode
- EM Heat = backup heating mode
At DuctOwl.com, we see Heat as the default setting for everyday comfort.
EM Heat is the backup option when the heat pump cannot work properly.
Q: When should I use EM Heat?
A: Use EM Heat only in specific situations, such as:
- The heat pump is not working
- The outdoor unit is iced over
- An HVAC technician tells you to use it
Do not use EM Heat just because it feels cold outside.
Q: Does EM Heat cost more than regular Heat?
A:
- Yes, EM Heat usually costs more
- It relies on backup heat
- Backup heat is often less efficient than normal heat pump operation
In simple terms, leaving EM Heat on too long can raise your energy bill.
Q: Is EM Heat the same as Aux Heat?
A:
- No, they are not the same
- Aux Heat often turns on automatically
- EM Heat is usually turned on manually
- EM Heat tells the system to use backup heat only
This is one of the most common thermostat misunderstandings homeowners have.
Q: What is the biggest mistake homeowners make with EM Heat?
A:
The biggest mistake is thinking EM Heat is a stronger or better everyday setting.
At DuctOwl.com, our practical view is simple:
- Heat is for normal use
- EM Heat is for temporary backup use
- EM Heat is not an upgrade
Bottom Line
- Use Heat for everyday heating
- Use EM Heat only when needed
- Keep EM Heat temporary
- Avoid unnecessary energy costs
- Let the heat pump do its normal job whenever possible
Take the Next Step With EM Heat vs Heat on a Thermostat: What Homeowners Actually Need to Know
Learn how to use the right thermostat setting with confidence so you can protect comfort, avoid wasted energy, and prevent costly mistakes. Explore the next step today and make smarter heating decisions for your home.