Winter storm power outage: keeping the heat on for 3 days
What it actually takes to keep a furnace, sump pump, and fridge running through a 3-day outage, and how to do it safely. Figures as of 2026-10-28.
Plan first, buy second. Ready.gov's advice is to list what in your home needs electricity, plan backup for it, install battery-backup CO alarms, and know where local warming centers are (Ready.gov, Power Outages, page updated 06/04/2026, read 2026-10-28). Run the winter storm scenario in the calculator →
Why this winter
NERC, which oversees North American grid reliability, scheduled its 2026–2027 Winter Reliability Assessment for release on November 18, 2026 (NERC schedule). We'll add its findings when it's out. Earlier this month, DOE issued emergency Order No. 202-26-50 to PJM, the grid operator for 13 states and DC, on October 12, effective October 13–16, 2026, so PJM could run specified units and call on backup generation as a last resort (DOE 202(c) orders). That order did not mean outages happened; it is a tool to prevent them.
1. The furnace blower: the key load
Most gas and oil furnaces won't heat without electricity, because the blower fan, controls, and igniter need power. A 1/2 HP furnace fan runs 300–800 W and needs up to 1,600 W to start (Champion Power Equipment wattage chart, as of 2026-10-25). Your furnace's label has its own number; use that if it differs.
Estimate At the 550 W midpoint and 12 hours of runtime a day, the blower uses about 6.6 kWh/day, or about 19.8 kWh over 3 days. Colder weather and leakier homes mean more hours.
A furnace has to be connected through a listed transfer switch or interlock installed by a licensed electrician, never a backfed outlet. Transfer switch vs interlock →
2. Sump pump
Snowmelt and freezing rain can keep a sump pump busy. A 1/3 HP pump runs 500–800 W with about 1,600 W to start; a 1/2 HP runs 800–1,050 W with 2,150 W to start (Champion). Assumption Our calculator defaults to 4.8 hours of pumping a day, which you should change to match your basement.
3. Space heaters: what they really need
A plug-in space heater draws 750–1,500 W (Champion). That's more than a furnace blower, for one room.
| Power station (capacity) | 1,500 W heater | 750 W heater | 550 W furnace blower |
|---|---|---|---|
| Anker SOLIX C1000 (1.056 kWh) | ≈0.6 h | ≈1.2 h | ≈1.6 h |
| Jackery Explorer 2000 v2 (2.042 kWh) | ≈1.2 h | ≈2.3 h | ≈3.2 h |
| EcoFlow DELTA Pro 3 (4.096 kWh) | ≈2.3 h | ≈4.6 h | ≈6.3 h |
| Jackery Explorer 5000 Plus (5.04 kWh) | ≈2.9 h | ≈5.7 h | ≈7.8 h |
Runtime = capacity × 0.85 usable ÷ watts Assumption. Capacities from HomeGridHQ and Home Battery Report, October 2026. Never leave a space heater running unattended, and plug it straight into the station or wall, not a power strip.
4. A sample 3-day winter plan
Estimate Fridge (8 h/day), furnace blower (12 h/day), 1/3 HP sump pump (4.8 h/day), Wi-Fi router, six LED bulbs, and phone charging come to about 12.8 kWh/day, or about 45 kWh for 3 days after the 0.85 usable factor. That's in the range of an installed battery bank or a generator, not a single portable station. Dropping the sump pump and running the blower 8 hours cuts it to about 7.5 kWh/day.
Ways to make it last: heat fewer rooms and close doors, keep the fridge and freezer shut (Ready.gov: a fridge keeps food cold for about 4 hours, a full freezer about 48 hours), and charge devices in the daytime. Try your own numbers →
5. Carbon monoxide: the real risk
- CDC: never use a generator inside your home or garage, even with doors and windows open, and only use it more than 20 feet from windows, doors, and vents (CDC, CO basics).
- Ready.gov: generators and fuel go outdoors, at least 20 feet from windows, doors, and attached garages, and never heat your home with a gas stove or oven (Ready.gov).
- Install battery-operated or battery-backup CO alarms on every level and near sleeping areas, and test them monthly (CPSC).
- CPSC found 43% of engine-driven tool CO deaths in 2011–2021 happened November through February, and weather outages from ice, snow, and storms were a leading reason people were running generators (CPSC report).
Battery power stations make no exhaust, which is one reason people use them indoors. If you'd feel cold or unsafe, Ready.gov's advice is to go to a community location with power.
Will your backup last 3 days? Check in the calculator → · Compare power stations · Standby generator costs
FAQ
Will my gas furnace work during a power outage?
Usually not. Most modern gas furnaces need electricity for the blower fan, controls, and igniter. A 1/2 HP furnace blower runs about 300–800 W and can need about 1,600 W to start (Champion Power Equipment wattage chart). Check your furnace's label or manual for its exact rating.
Can a portable power station run my furnace?
A station rated above the blower's starting watts can run the fan, but it has to connect through a listed transfer switch or interlock installed by a licensed electrician, or a furnace made to plug in. At a typical 550 W for 12 hours a day, the blower alone uses about 6.6 kWh per day, more than most single portable stations hold.
How long will a power station run a space heater?
Not long. A plug-in space heater draws about 750–1,500 W (Champion). A 2.04 kWh station like the Jackery Explorer 2000 v2, with 85% usable, runs a 1,500 W heater for about 1.2 hours. Heating one room by running the furnace blower is usually a better use of stored energy.
Is it safe to run a generator in the garage with the door open?
No. CDC and CPSC say never use a generator inside a home or garage, even with doors and windows open. Ready.gov says to keep generators at least 20 feet from windows, doors, and attached garages.
Can I heat my house with a gas oven or stove?
No. Ready.gov says never use a gas stovetop or oven to heat your home because it raises your carbon monoxide risk.
Backup power, before the next outage
A short email when it matters: outage-season prep checklists before summer storms and winter freezes, state and utility rebates that open, change, or run out of money, and real price drops on the power stations in our data.