Do You Have to Relight Furnace After Power Outage

Do You Need to Relight Your Furnace After a Power Outage?

Power outages can disrupt home heating systems, leaving many homeowners wondering if they need to relight their furnace once electricity is restored. This article explores how furnaces operate during and after power interruptions, common furnace types, relighting procedures, and safety tips to ensure your home stays warm and secure without unnecessary hassle.

How Different Furnaces React To Power Outages

Most homes in the U.S. use either electric furnaces or gas furnaces with various ignition systems. Understanding the type installed helps determine if relighting is required after an outage.

Electric Furnaces

Electric furnaces rely entirely on electrical power. When the power goes out, the furnace stops functioning immediately. The good news is that once power is restored, electric furnaces usually start without any manual intervention. Users may want to check their thermostats to ensure settings remain correct.

Gas Furnaces With Electronic Ignition Systems

Modern gas furnaces often use electronic ignition or intermittent pilot systems. These systems automatically reignite the burner after power is restored because the control module saves the ignition sequence. In most cases, homeowners do not need to relight anything themselves. However, if the furnace does not restart, checking power interruptions, circuit breakers, and the control board is advised.

Gas Furnaces With Standing Pilot Lights

Older gas furnaces use a continuously burning pilot light to ignite the main burner. A power outage by itself does not typically affect the pilot light, since it is fueled by gas, not electricity. However, if the outage was accompanied by a draft, vibration, or gas supply disruption, the pilot light might go out. In this case, the homeowner must manually relight the pilot light following safety procedures.

Steps to Safely Relight a Furnace After a Power Outage

If you have a gas furnace with a standing pilot light and need to relight it, follow these basic safety steps. Always consult your furnace’s user manual as models differ.

1. Turn off the furnace and gas supply.
2. Wait at least 5-10 minutes to allow any gas to clear from the area.
3. Locate the pilot light assembly and gas valve.
4. Turn the gas valve to “pilot” and press the knob to release gas.
5. Use a long lighter or match to ignite the pilot while holding the knob.
6. Keep the knob pressed for 30-60 seconds to allow the thermocouple to heat up.
7. Release the knob and verify if the pilot stays lit.
8. Turn the valve back to “on” and restart your furnace.
9. If unsure, or the pilot won’t stay lit after several attempts, call a professional technician.

When to Call a Professional Technician

Safety is paramount when dealing with gas appliances. If the pilot light does not stay lit, there is a strong gas odor, or the furnace shows abnormal behavior after a power outage, contact a certified HVAC technician immediately. Improper handling of gas lines and pilot lights can lead to leaks or fire hazards.

Additionally, electronic ignition issues after power restoration might require professional inspection to rule out damaged control boards or faulty ignition components.

Useful Tips For Maintaining Furnace Functionality During Power Outages

• Install a generator or battery backup for uninterrupted power supply to your furnace.
• Keep your gas furnace well maintained, including pilot lights or ignition system checks.
• Learn to manually relight the pilot light safely as a precaution.
• Test your furnace immediately after power returns to ensure proper operation.
• Keep a carbon monoxide detector in the furnace area for early warning of leaks.
• Ensure your thermostat has fresh batteries to maintain settings during outages.

Summary Table: Furnace Relighting Requirements After Power Outages