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Home › Guides › Running a furnace on a generator · Checked Nov 15, 2026

Can I run my furnace on a generator?

The short answer

Yes, if you connect it the safe way. A gas furnace burns gas for heat, but its blower and controls need electricity. It’s hardwired, so an extension cord won’t reach it.

~500 Wtypical furnace fanHomeGuide
Hardwiredneeds a panel connection
Electric heatoften means the 40-amp device or a standby

Three safe ways to connect

  2. Interlock + inletAny utility
  3. Transfer switchAny utility, wired circuits

Never backfeed a plug. DTE’s FAQ says its device runs anything in your panel up to the generator’s capacity, including electric baseboard heat. (DTE FAQ)

More detail

Gas or electric?

Gas furnace

  • The blower is the main load
  • A 30-amp portable setup usually has room for it plus the fridge and sump
  • Some control boards are picky about generator power: ask your HVAC company

Electric furnace or baseboard

  • Check the nameplate watts first
  • Can outgrow 7,200 W fast
  • Often the standby case

Winter checklist

  1. Clear snow from the furnace’s outside vents. (CPSC)
  2. CO alarms on every level. Battery or battery backup.
  3. Generator outside, 20+ feet away. Exhaust pointed away from the house.
  4. Furnace first, then the rest. Turn circuits on one at a time.

Questions people ask

Can I run my gas furnace on a portable generator?

Yes, through a safe connection to your panel: DTE’s meter plug, an electrician-installed interlock and inlet, or a transfer switch. HomeGuide lists a furnace fan at about 500 watts.

What size generator do I need to run a gas furnace?

The furnace fan is about 500 running watts in HomeGuide’s chart. Add your other must-haves; furnace, fridge, sump and lights together usually fit a 7,200-watt setup.

Can I plug my furnace into a generator with an extension cord?

Most furnaces are hardwired, so no. Use a safe panel connection. Never use a double-male cord in an outlet.

Can I run an electric furnace on a generator?

Sometimes, but electric heat can need several thousand watts. Check the nameplate. Many homes with electric heat are a better fit for a standby.

Keep reading

Two rules that save lives

Never run a generator in a garage, porch or near a window. Keep it 20 feet out, exhaust away.

Never backfeed through a dryer outlet. A ‘double-male’ cord can electrocute a lineman down the street. Your plan uses only safe, legal ways to connect.

Not sure which fits your house? A few taps about your home and what has to stay on. Free, and no email needed to see your plan.

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Sources (checked Nov 15, 2026)

Lights Back On is not affiliated with DTE Energy. Educational content only; not electrical advice.