When the temperature plummets and your heating system starts acting up, the question "should i use emergency heat" can trigger immediate anxiety. This setting is often labeled in red on your thermostat and accompanied by a warning symbol, suggesting that it is a last resort rather than a standard function. Understanding when this drastic measure is necessary—and when it is better to simply call a professional—can save you from unexpected energy bills and potential system damage.
Understanding Emergency Heat Mode
Emergency heat is not a feature designed for convenience; it is a backup protocol for when your primary heating source fails. Typically found on heat pump systems, this setting bypasses the outdoor unit entirely. Instead of extracting warmth from the cold air outside, the system relies solely on internal electric resistance strips or secondary fossil fuel sources. Because this process consumes significantly more energy to generate the same amount of heat, it is intended for true emergencies only.
Identifying True Emergencies
You should evaluate the situation based on the severity of the failure. A true emergency exists when your primary heat pump is completely non-functional due to factors like a refrigerant leak, a faulty reversing valve, or a total power loss to the outdoor unit. If the system is running but struggling in extreme cold, that usually does not qualify as an emergency requiring the emergency heat setting. In these cases, the heat pump is often still doing 80% of the work, and switching to emergency mode actually makes the system work harder and less efficiently.
The Energy and Cost Implications
Using the emergency heat setting has a direct and significant impact on your utility bill. Standard heat pumps are efficient because they move existing heat rather than creating it. However, electric resistance heat—the method used in emergency mode—works exactly like a space heater. It generates heat by forcing electricity through coils, which consumes up to three times more energy. If you activate this setting for an extended period without addressing the underlying issue, you could face a substantial spike in costs by the time the repairman arrives.
Heat pumps typically operate at 300-400% efficiency under normal conditions.
Emergency electric resistance heat operates at nearly 100% efficiency, but requires much more electricity to produce the same heat.
The average cost to operate emergency heat can be double or triple the cost of standard heating.
Operational Risks and System Strain
Beyond the financial cost, constantly asking the question "should i use emergency heat" puts immense strain on your system's components. The heating elements are not designed to run continuously for hours on end. Prolonged use can cause the safety limit switches to overheat and shut down, potentially leading to a complete burnout of the auxiliary heat strips. Furthermore, the sudden shift in operations can cause pressure imbalances in the refrigerant lines, risking further damage to the core components that the emergency setting was meant to protect.
When to Use It (and When Not To)
The decision tree for using this setting is straightforward. You may consider using emergency heat only if a certified HVAC technician has explicitly instructed you to do so while they are on their way. If your heat pump is blowing cold air because of a power surge or a tripped breaker, and the technician confirms the outdoor coil needs to thaw, a short activation might be appropriate. However, if your system is noisy but still producing warm air, turning on emergency heat is unnecessary and wasteful.
The Professional Alternative
Rather than relying on the emergency setting, the most effective strategy is prevention and rapid response. Schedule regular maintenance before the winter season to ensure your defrost cycle and refrigerant levels are optimal. If your system does fail, the best course of action is to turn the thermostat to the "off" position and contact a professional. This prevents the system from cycling incorrectly and allows the technician to diagnose the root cause without the added stress and expense of emergency heat usage.
