Hi, neighbor! Bert Miskell here from BPM Heating & Cooling in Frederick, MD. Let’s clear up the mystery behind that “EM Heat” setting on your thermostat. Whether you’re facing a chilly morning or troubleshooting a heat pump issue, understanding emergency heat can save you time, money, and stress.
What Is Emergency Heat (EM Heat)?
Emergency Heat, or EM Heat, is a backup heating mode on your thermostat used with heat pump systems. It’s designed to kick in when your heat pump can’t keep up with demand or is malfunctioning.
Key characteristics of EM Heat:
- Uses electric resistance or gas-powered heating elements
- Bypasses the heat pump entirely
- Consumes significantly more energy than normal heat pump operation
- Provides immediate but costly heating backup
When Should You Use Emergency Heat?
Only use EM Heat when necessary. It’s a short-term solution, not a daily heating method.
Turn on EM Heat if:
- Your outdoor heat pump unit is not working
- You notice system shutdowns during freezing weather
- Your heat pump is in defrost mode but the home stays cold
- You’re waiting for heat pump repairs and need temporary warmth
Avoid using EM Heat during mild winter days or as your primary heating source unless instructed by an HVAC technician.
EM Heat vs. Heat Pump Mode
| Feature | Heat Pump Mode | EM Heat Mode |
| Energy Efficiency | High (uses outdoor air) | Low (electric resistance only) |
| Usage Frequency | Daily primary heating | Emergency or temporary only |
| Operation Temp Range | Effective above 35°F | Effective in sub-freezing temps |
| Cost to Operate | Low | High |
EM Heat vs. Aux Heat
Though both serve as backups, they operate differently:
Aux Heat activates automatically when the heat pump needs extra support. EM Heat is a manual override used when the heat pump isn’t working.
If you’re constantly relying on either, it may signal that your system needs a tune-up or repair.
How to Activate EM Heat
Most thermostats allow you to manually turn on EM Heat. Here’s how:
- Digital or Smart Thermostats: Navigate to “Settings” and select “Emergency Heat”
- Manual Thermostats: Flip the switch labeled “EM Heat” or “Emergency”
- Touchscreen Displays: Use the on-screen menu to enable EM Heat mode
Always monitor the thermostat screen for confirmation and shut off EM Heat when it’s no longer needed.
Why EM Heat Is So Expensive
Because EM Heat bypasses your energy-efficient heat pump and uses electric resistance coils, it can cost 2-3 times more to operate.
Cost Comparison:
- Heat pump: ~$0.13/hour
- EM Heat: ~$32/week (for light use)
Prolonged EM Heat usage can cause a spike in your utility bills. Use it only when necessary.
Signs You May Need Emergency Heat
- The outdoor unit is frozen or malfunctioning
- Indoor temperature is well below the thermostat setting
- System won’t cycle or shuts down repeatedly
- Ice buildup on the heat pump and defrost cycle isn’t working
If these symptoms occur, switch on EM Heat temporarily and call BPM Heating & Cooling for service.
Final Thoughts: Use EM Heat Wisely
Think of EM Heat as your home’s backup generator: vital in emergencies, but costly and unsustainable for long-term use. If you’re finding yourself needing EM Heat often, it’s time to schedule a maintenance check.
At BPM Heating & Cooling, we specialize in diagnosing heat pump issues and ensuring your backup systems work when you need them most. We offer free quotes, repairs, and full system installs for homes and businesses across Frederick, MD.
Call us at (240) 200-0887 or visit bpmhvac.com to schedule service. Our expert team is here to keep you warm, no matter how cold it gets.
