Accidentally Turned on Emergency Heat: How it Differs from Regular Heating

Brief Explanation of Emergency Heat

When you turn up the heat on your thermostat, you expect your primary heating system to kick in and keep you warm. However, what happens when outside temperatures do drop too low for your primary heating system to operate effectively? This is where emergency heat comes in.

Emergency heat, also known as “em heat” or backup heat, is a secondary source of heat that kicks in when the primary heating system can’t keep up. It is typically used with a heat pump system, which operates differently from heat pumps from an electric furnace or other types of heating systems.

Personal Anecdote of Accidentally Turning on Emergency Heat

Last winter, I experienced an unexpected increase in my electricity bill and couldn’t figure out why. Things started to make sense when I realized that I had accidentally turned on the “aux heat” setting on my thermostat.

Little did I know, this setting activates the electric heat strip – aka emergency backup heating – instead of my primary system. I soon discovered that this mistake was going to cost me dearly in terms of a higher electricity bill.

Emergency heat uses more energy than regular heating due to its reliance on electric resistance heating instead of a more efficient heat pump, but it can also cause costly repairs if overused or used improperly. Knowing how to properly operate and identify emergency backup heating can save you from unwanted costs and headaches during cold temperatures.

What is Emergency Heat?

Defining and Explaining Emergency Heat

Emergency heat is a common feature in most heat pump systems. It is also known as “auxiliary heat” or “second-stage heating”. The primary purpose of emergency heat is to provide additional warmth when the outside air temperature drops below freezing and the main heat pump or system can no longer extract enough heat from the outside air to warm up your indoor air.

When you turn on your heating system, it usually operates in normal heating mode using a reversing valve that extracts heat from the outside air and circulates it to both heatings and through your indoor unit. However, if for any reason, such as extreme cold, defrost mode, or a malfunctioning outdoor unit, your system cannot extract enough warmth from the outside air to meet your thermostat’s designated temperature setting, then emergency heat automatically activates.

The Purpose of Emergency Heat

The main purpose of emergency heat is to provide extra warmth when the normal heating process won’t suffice. When temperatures drop below freezing and there isn’t enough warm air from the outdoors to keep homes at comfortable temperatures, many heating systems fail when they reach their maximum capacity.

This is where emergency or auxiliary heating comes into play. One important aspect of emergency heat is that it uses only secondary sources of energy (such use emergency heat such as electric resistance coils) instead of relying on gas furnaces as most normal heating setups do.

This feature makes this type of system more efficient and less expensive overall.

Difference between Normal Heating vs. Emergency HeatIt’s important to understand that while both normal heating and emergency/auxiliary heating share some similarities in their function (i.e., they both work toward keeping your home warm), there are some key differences between them. Normal heating runs on a reversing valve mechanism that extracts warmth directly from outdoor air even in cold weather, while emergency heat relies on a secondary heat source, heating elements or backup systems to supplement the main heating source. Emergency heating is designed to be used during times of extreme cold or when there are issues with the outdoor unit.

How to Identify if Emergency Heat is On

Checking Thermostat Settings:

The first step in identifying if emergency heat is on is to check the thermostat settings. If your thermostat has a separate “aux heat” or “emergency heat” setting, make sure it is turned off.

This setting should only be used in extremely cold weather when normal heating isn’t enough to keep your home warm. Using emergency heat as a primary heating source can significantly increase your electricity bill and cause damage to your HVAC system.

Listening for Unusual Sounds from the HVAC System:

Another way to identify if emergency heat is on is by listening for unusual sounds coming from your HVAC system. When emergency heat mode is activated, your secondary system will kick in and use a different source of heat, like electric resistance coils or gas burners, to generate warmth. This can cause the indoor unit of your HVAC system to make loud clicking or buzzing noises that are not present during normal heating mode.

Feeling for Warm Air Coming from Vents:

If you’re still unsure whether the emergency heat is on, try feeling for warm air coming from the vents. During normal heating, warm air should be blowing steadily through all the vents in your home.

However, when emergency heat is activated, you might notice that some rooms are warmer than others or that there’s not enough warmth coming from certain vents. This can happen when the reversing valve doesn’t switch properly between cooling mode and heating mode or when there’s an issue with the outdoor unit of your HVAC system.

Overall, it’s important to check for these signs of emergency heat activation regularly during cold weather months so that you can stay warm without causing damage to your HVAC system or running up expensive electricity bills unnecessarily. If you’re still unsure if the emergency heat is on after checking these indicators, consider consulting an HVAC professional or technician for advice and guidance.

Consequences of Running Emergency Heat

Increased Energy Consumption and Cost: When it comes to the emergency heat feature, it’s important to remember that it is intended only for use in extremely low temperatures when the primary heating system can’t keep up. This means that running your HVAC system using emergency heat over an extended period can lead to a significant increase in your electric bill. As the name suggests, this option should be reserved for emergencies only.

Potential Damage to HVAC System: Another consequence of running emergency heat is potential damage to your HVAC system. The electric or gas furnace being used during emergency heating puts a lot of strain on the system, which can result in issues such as burnt-out capacitors or damaged compressors. In addition, using emergency heat too frequently or for extended periods can result in the shortened lifespan of your entire HVAC system.

Reduced Comfort due to Uneven Heating: While using emergency heat may seem like a quick fix, be aware that it usually results in uneven heating throughout your home. The primary function of an HVAC system is to maintain a desired temperature throughout your home by cycling through cooling mode and heat mode as needed. However, when you accidentally turn on emergency heat, you’re bypassing the traditional cycle and kicking on secondary heating mechanisms like backup heat strips or electric resistance coils instead – which will usually cause some rooms to become warmer than others. All things considered, accidentally turning on emergency heat should be avoided if possible – not only because it can lead to increased energy costs, potential damage to your HVAC unit or system, and reduced comfort due to uneven heating but also because it defeats the purpose of having a backup system in place should you need it. If you do need to use this feature from time to time during winter months when temperatures are very low and conventional heating doesn’t suffice – make sure you know how long to run it to avoid unnecessary costs and damage. As always, be sure to double-check your thermostat settings and know the difference between the em heat setting and the aux heat setting.

How to Turn Off Emergency Heat

Have you accidentally turned on emergency heat and now your electric bill is through the roof? Don’t worry, turning off the emergency heat is a simple process.

First, locate your thermostat and manually switch it to “heat” mode. Next, find the button that says “aux heat” or “emergency heat” and press it until the indicator light turns off.

This will disable the secondary heating system at the source and allow your primary heating system to take over again. If you have a heat pump system, you may need to go outside and check the outdoor unit as well.

Some systems have a separate switch that controls emergency heat for the outdoor unit. Simply flip this switch back to its original position to turn off the emergency heat completely.

Tips for Preventing Accidental Activation in the Future

Accidentally turning on the emergency heat can be frustrating and costly, but there are steps you can take to prevent it from happening again in the future. First and foremost, familiarize yourself with your HVAC units and their settings. Make sure you know which buttons control emergency heat so that you don’t accidentally press them.

Another tip is to keep an eye on the temperature outside. If it’s not cold, there’s no need for auxiliary heating unless your primary system isn’t working properly.

Make sure your thermostat is working correctly by regularly testing it in different modes. By following these tips, you can avoid costly repairs and keep your electric bill under control while still staying warm during freezing temperatures.


Accidentally turning on the emergency heat can be frustrating, but it’s not the end of the world. Following these simple steps for turning off auxiliary heating sources like emergency or aux heat settings along with taking measures to avoid accidental activation in future cases will help save costs of energy bills while ensuring comfort during freezing temperatures with primary systems like natural gas and heat pump systems.

Recap of Key Points

In this article, we’ve learned about emergency heat – what it is, how to identify if it’s on, the consequences of running it, and how to turn it off. Emergency heat is a secondary system that operates differently from your primary heating system.

It is designed to be used in particularly cold temperatures or when your primary heating system is not working properly. However, running emergency heat for an extended period can result in increased energy consumption and cost, potential damage to your HVAC system, and reduced comfort due to uneven heating.

Reminder to be Cautious When Adjusting Thermostat Settings

One lesson we can take away from accidentally turning on the emergency heat is the importance of being cautious when adjusting thermostat settings. It’s easy to make a mistake or unintentionally hit the wrong button, especially if you’re not familiar with your HVAC system.

Take the time to read through your thermostat manual and understand what each button does before making any adjustments. It’s also helpful to pay attention to outdoor temperatures and adjust your thermostat setting accordingly.

If temperatures drop significantly overnight, you may need to adjust your thermostat so that your HVAC system can maintain a comfortable indoor temperature without relying on emergency heat. And remember – always set your thermostat back when you leave the house or go to sleep to save money on your electric bill.

An Optimistic Spin

While accidentally turning on the emergency heat can be frustrating and costly, it’s also an opportunity for us all to learn more about our heating and cooling systems. By understanding how our air handlers work in different modes (heating vs cooling vs defrost), we can improve our comfort levels at home while also saving money on our electric bills. So let’s embrace these moments as opportunities for learning and growth – who knows what other HVAC tricks we might discover along the way!

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Frequently Asked Questions:

Is it detrimental to leave emergency heat on for an extended period?

Keeping emergency heat on for an extended period can be disadvantageous due to its higher energy consumption and potentially higher utility costs.

Does using emergency heat lead to increased utility bills?

Yes, using emergency heat can result in higher utility bills due to its less energy-efficient nature compared to the primary heating method.

Does a heat pump automatically transition to emergency heat mode?

Heat pumps do not automatically switch to emergency heat mode. It usually requires manual activation or a specific setting adjustment.

What is the process for deactivating emergency heat?

To turn off emergency heat, you typically need to adjust the thermostat settings or switch back to the regular heating mode. Consult your specific thermostat manual or seek professional assistance if needed.

If you found this article enjoyable, you might also find these related articles or resources of interest:

Surviving the Cold: Your Ultimate Guide to Emergency Heating Solutions

Surviving the Chill: A Comprehensive Guide to Emergency Heat in Heating Systems.

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