If your furnace breaks down, it can be inconvenient and uncomfortable, especially during colder months. Here’s a step-by-step guide on what to do if your furnace stops working:

1. Check the Thermostat: Make sure the thermostat is set to the desired temperature and is in “Heat” mode. Sometimes, the issue might be as simple as a thermostat setting.

2. Check Power Supply: Ensure that the furnace is receiving power. Check the circuit breaker or fuse box to see if the circuit for the furnace is tripped or if a fuse is blown.

3. Reset the Furnace: Some furnaces have a reset button. If you’re comfortable doing so, you can try resetting the furnace by following the manufacturer’s instructions.

4. Inspect the Pilot Light (Gas Furnace): If you have a gas furnace, check the pilot light. If it’s out, follow the manufacturer’s instructions to relight it. If the pilot light doesn’t stay lit, there could be a more significant issue that requires professional attention.

5. Check the Air Filter: A clogged air filter can lead to poor airflow and overheating. Check the filter and replace it if it’s dirty or clogged.

6. Look for Error Codes: Some modern furnaces have LED displays that provide error codes. Refer to your furnace’s manual to understand what the error codes mean.

7. Check Gas Supply (Gas Furnace): If you have a gas furnace, make sure the gas supply to the furnace is turned on. If you suspect a gas leak, leave your home immediately and call your gas provider.

8. Inspect Vents and Exhaust: Ensure that air vents and exhaust pipes are clear of debris and snow, especially if your furnace is located outside.

9. Call a Professional: If you’ve tried the above steps and your furnace still isn’t working, it’s time to call a professional HVAC technician. Attempting to fix complex issues on your own can be dangerous and may cause further damage.

10. Stay Warm: In the meantime, dress warmly, use blankets, and consider using space heaters to keep warm until the furnace is repaired.

Remember that furnace repairs can be complex and potentially dangerous, especially if you’re dealing with gas furnaces. It’s best to leave the diagnosis and repair to trained HVAC technicians. Regular maintenance can also help prevent breakdowns, so consider scheduling annual maintenance checks to keep your furnace in optimal condition.