Few things are more stressful than waking up to a freezing house in the middle of winter. While a complete furnace shutdown can be alarming, there are a few safe steps homeowners can take before calling for emergency service.
Step 1: Check the Thermostat
It sounds simple, but thermostats are often the culprit. Make sure:
- It’s set to Heat
- The temperature is above room temp
- Batteries are not dead
Step 2: Inspect the Air Filter
A severely clogged filter can cause the furnace to overheat and shut off. If it’s dirty, replace it immediately.
Step 3: Check the Breaker Panel
Sometimes the furnace loses power due to a tripped breaker. Reset it once – if it trips again, stop and call a professional.
Step 4: Look at the Exhaust Vent
Heavy snow or ice can block furnace exhaust pipes, forcing a shutdown. Carefully clear any visible obstruction.
Step 5: Use Backup Heat Safely
If the home temperature continues to drop:
- Use space heaters with auto shut-off
- Keep heaters 3 feet from objects
- Never use ovens or grills indoors
When To Call A Professional
If none of these steps restore heat, it’s time for emergency service. Avoid DIY internal furnace repairs. Modern systems involve gas lines, electrical components, and safety switches that require trained handling.
Final Thoughts
Most furnace failures have warning signs before they fully stop. Regular maintenance dramatically reduces the risk of middle-of-the-night emergencies. When heat fails, safety comes first – comfort comes second.

