Best Battery Backup for Gas Furnaces
Gas furnaces rely on electricity to power the igniter, control board, blower fan, and safety systems. When the power goes out, your furnace stops working—even if you have a steady gas supply. A battery backup keeps your furnace running during outages, preventing frozen pipes, maintaining safe indoor temperatures, and avoiding costly damage. This guide highlights battery systems that deliver clean AC power, handle motor startup surges, and provide enough runtime for multi-hour heating continuity.
Below is our top pick for most gas furnace setups, followed by four additional options that excel in different scenarios. Each recommendation includes specs, pros and cons, and real‑world review insights to help you choose the right backup for your furnace.
🔋 EcoFlow DELTA 2 – Best Overall Battery Backup for Gas Furnaces
The EcoFlow DELTA 2 delivers pure sine wave output and strong surge handling, making it ideal for powering gas furnaces during outages. It supports blower motors up to 700W and handles startup surges up to 2700W. The LiFePO4 battery lasts over 3000 cycles, and the unit recharges quickly via AC or solar.
Key Specs
- Capacity: 1024Wh (expandable)
- Output: 1800W continuous / 2700W surge
- Waveform: Pure sine wave
- Best for: Single-stage and two-stage gas furnaces
Pros
- Handles blower motor startup surge
- Long runtime for multi-hour outages
- Fast recharge and expandable battery
- Quiet and safe for indoor use
Cons
- Higher cost than DIY inverter setups
- Requires outlet access near furnace
Customer Review Highlights
Homeowners report successful furnace operation during outages using the DELTA 2, with runtimes ranging from 4 to 10 hours depending on furnace duty cycle. Many mention quiet operation and seamless startup without flicker or overload.
View EcoFlow DELTA 2 on Amazon
More Great Battery Backups for Gas Furnaces
These options deliver clean power, surge protection, and enough runtime to keep your furnace running safely during outages.
📦 Bluetti AC180
The Bluetti AC180 is a powerful LiFePO4 power station with 1800W output and 2700W surge handling. It’s ideal for mid-size furnaces and offers fast AC recharge.
Specs
- 1152Wh capacity
- 1800W continuous / 2700W surge
- Pure sine wave inverter
Pros
- Excellent surge handling
- Long-life battery chemistry
- Quiet and compact
Cons
- Heavier than smaller units
- Premium price
🔋 Jackery Explorer 1000 Plus
The Jackery Explorer 1000 Plus offers 1264Wh of capacity and 2000W surge handling, making it suitable for most residential gas furnaces. It’s lightweight and expandable.
Specs
- 1264Wh capacity
- 2000W surge
- Pure sine wave output
Pros
- Expandable battery options
- Quiet and portable
- Safe for indoor use
Cons
- Not ideal for large multi-zone systems
- Slower recharge than EcoFlow
View Jackery Explorer 1000 Plus
🌐 APC Smart-UPS 1500VA
The APC Smart-UPS 1500VA is a pure sine wave UPS designed for sensitive electronics. It can power small furnaces during short outages and supports USB monitoring.
Specs
- 1500VA / 1000W
- Pure sine wave
- LCD screen, AVR, USB monitoring
Pros
- Reliable APC build quality
- Great for short outages
- Quiet operation
Cons
- Lead-acid battery requires replacement
- Limited runtime for blower motors
💡 EcoFlow River 2 Pro
The EcoFlow River 2 Pro is a compact option for small furnaces or short outages. It’s lightweight, fast-charging, and uses long-life LiFePO4 cells.
Specs
- 768Wh capacity
- 800W continuous / 1600W surge
- Pure sine wave output
Pros
- Affordable LiFePO4 option
- Fast AC recharge
- Lightweight and portable
Cons
- Not ideal for blower motors over 600W
- Shorter runtime than 1kWh+ units
How to Choose a Battery Backup for Gas Furnaces
1. Choose pure sine wave output. Furnace control boards and motors require clean power to operate safely.
2. Check surge capacity. Blower motors often spike 2x their running wattage at startup.
3. Size your battery correctly. Most furnaces draw 400–700W during operation.
4. Prefer lithium power stations for long outages.
