Have you seen “EM Heat” on your thermostat and wondered what it does? Emergency heat, often abbreviated EM Heat on thermostats, is designed to keep you warm when your main system can’t keep up. Let’s clear the confusion so you know exactly when to use emergency heat and when other solutions are necessary.
What Does Emergency Heat Do?
Emergency heat is basically your HVAC system’s plan B. Most homes with heat pumps rely on moving heat from the outdoor air into your home to keep you warm. When the heat pump can’t do its job, the emergency heat kicks in, bypasses the heat pump entirely, and uses a secondary heat source to generate warmth.
Think of it like a spare tire on your car. It’s useful when you need to use emergency heat, but it’s not reliable for the long-term. It’s just a temporary fix until you can get your primary system back up and running.
How Emergency Heat Works with a Heat Pump
Heat pumps are fantastic at efficient heating, but they have physical limits. When temperatures drop extremely low, extracting heat becomes harder. Usually, your system automatically triggers auxiliary heat to help the pump along. This acts as a temporary boost to keep the temperature steady without shutting off the main pump.
When you manually switch to Emergency Heat, you force the system to ignore the heat pump completely. Instead, it relies 100% on the backup heating strips (electric) or furnace (gas). But it’s important to know when this is necessary.
When to Use Emergency Heat
So, when should you use emergency heat? You really only need it in specific scenarios.
- Heat Pump Failure or Malfunction: If your main unit stops running or sounds like it’s breaking, switch to emergency heat to stay warm while you call for repairs.
- Extremely Cold Outdoor Temperatures: If it’s well below freezing and your heat pump is completely iced over or struggling to maintain any warmth, this setting can help temporarily.
- After Severe Weather or System Damage: If a tree branch hits your outdoor unit or a storm damages it, turn on EM heat to prevent further damage.
- Temporary Use While Waiting for Repairs: If a technician is scheduled but hasn’t arrived yet, emergency heat can keep your home livable in the meantime.
When Not to Use Emergency Heat
It might be tempting to use this setting to make your house toasty fast, but don’t do it! Using it incorrectly can cost you.
- Normal Cold Weather Conditions: Your heat pump is designed to handle standard winter days. Let it do its job efficiently.
- To Heat the Home Faster: While the air might feel hotter coming out of the vents, it is much more expensive to run than your standard heat pump cycle.
- Long-Term or Everyday Heating: Relying on emergency heat for days or weeks will cause your electric bill to skyrocket due to the high energy consumption.
- When the Heat Pump is Still Functioning Properly: If the outdoor unit is working, let it run. It is far more efficient than the backup electric strips.
Signs Your Emergency Heat Indicates a Bigger Problem
Sometimes, your thermostat switches to emergency or auxiliary heat on its own. While occasional use is normal during a freeze, constant use is a red flag. If you spot these signs when your house uses emergency heat, you might need to call a professional to check out your systems.
Emergency Heat Running Constantly
If the light never goes off, your heat pump might be broken, or the thermostat might be wired incorrectly. The system shouldn’t rely on the backup source 24/7.
Sudden Spike in Energy Bills
Emergency heat strips use a large amount of electricity compared to the heat pump. A surprise bill often means the backup heat is running too much.
Home Not Warming Properly
If the emergency heat is on but you are still shivering, you might have a problem with the backup strips or furnace ignition.
Warning Lights or Thermostat Alerts
Modern thermostats often tell you when something is wrong. Don’t ignore those flashing icons or error codes, as they usually point to specific system failures.
Triad Mechanical: Trusted Repair When You Need It Most
Heating issues can be stressful, especially when the temperatures drop. If you’re not sure when to use emergency heat or why your emergency heat is running, don’t guess and risk a high bill. At Triad Mechanical, our skilled technicians are available 24/7 to restore warmth and comfort to your home. We can diagnose the issue quickly and get your main system running.
Contact us today to ensure your heating system is ready for whatever winter brings.