Heating care
What Is Emergency Heat?
Emergency heat is a manual heat-pump setting that turns off the outdoor heat pump and uses the system’s backup heat source instead. It is meant to keep the home warm while a heat-pump problem is being addressed, not to give the system extra power on an ordinary cold day.
Emergency heat uses backup heat on its own
A heat pump normally moves heat from outside air into the home. Emergency heat changes that operation by taking the heat pump out of the heating cycle and relying on a backup source. As Lennox explains in its heat-pump support guidance, that backup may be electric heat from the indoor unit, or it may be another source such as gas, oil, or hot-water backup.
The setting only applies to homes with a heat pump. If your home uses a conventional furnace with air conditioning, you will not have an emergency-heat mode to select. Thermostat labels vary, but you may see Emergency Heat, EM Heat, or a similar option in the system mode menu.
Auxiliary heat can be normal, emergency heat is different
Auxiliary heat and emergency heat both involve backup heating, which is why the labels are easy to confuse. Auxiliary heat can switch on automatically when a heat pump needs help keeping up, including during cold conditions or a defrost cycle. The outdoor unit can still be part of the heating process.
Emergency heat is the manual override. It tells the system to stop using the heat pump and use the backup heat by itself. That distinction matters because a healthy system may use auxiliary heat from time to time without needing a repair, while manually selecting emergency heat points to a reason the primary heat-pump operation should be checked.
Emergency heat is for a heat pump that cannot operate normally
Emergency heat can be a short-term way to maintain warmth when the outdoor unit has stopped operating, has visible damage, or cannot run without concern. The goal is to keep the home comfortable while arranging a professional diagnosis, not to keep the backup system running indefinitely.
If you are unsure whether the setting is appropriate for your equipment, use the thermostat and system documentation for your specific model. The right backup source and controls differ from one system to another, so a general online instruction should not replace the manufacturer’s guidance for your home.
Cold weather alone is not a reason to switch it on
A heat pump is designed to manage normal winter operation with its controls and, when needed, automatic auxiliary heat. Manually turning on emergency heat because the temperature has dropped can take a functioning heat pump out of service when it is still able to contribute to heating the home.
Backup heat may use energy differently from the heat pump’s normal operation. The practical response to a cold house is to notice what the system is doing, avoid repeated thermostat changes, and schedule service if the home is not reaching the setting or the outdoor equipment is not operating as expected.
What to note before you call for heating service
You do not need to diagnose the system before calling. A few details can make the conversation clearer: whether the thermostat shows an alert, whether the outdoor unit is running, when the comfort change began, and whether the problem affects the whole home or only part of it. Those observations help a technician begin with the right questions.
Avoid opening equipment panels or trying to bypass thermostat controls. Heating equipment, electrical components, and system settings need to be considered together. If the system is not behaving normally, leave detailed inspection and repair to a qualified professional.
A heating visit can clarify the right next step
Preventive Home Solutions provides heating service for Northern Utah homes, including heat-pump, furnace, and boiler concerns. The team can review what the system is doing, explain the available solutions, and help you decide whether the issue calls for repair, maintenance, or a different next step.
Emergency heat is a useful backup when it is used for its intended job. Knowing the difference between automatic auxiliary heat and manual emergency heat can help you describe the problem clearly and avoid treating a normal cold-weather cycle like an equipment failure.
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Frequently asked questions
Is emergency heat the same as auxiliary heat?
No. Auxiliary heat can come on automatically to help a heat pump meet the thermostat setting. Emergency heat is a manual setting that relies on the backup heat source by itself.
Does every heating system have emergency heat?
No. Emergency heat is a heat-pump setting. A home with a standard furnace and air conditioner does not use this thermostat mode.
Should I use emergency heat during a cold spell?
Not simply because the weather is cold. A properly operating heat pump can use auxiliary heat automatically when needed. Emergency heat is for a heat pump that cannot operate normally while you arrange service.
