How long will an EcoFlow RIVER 3 run a gas furnace?
It will not. A gas furnace draws 600 W and the EcoFlow RIVER 3's inverter is rated at 300 W, so the station will refuse the load rather than run it slowly. Capacity is irrelevant here — you need a bigger inverter, not a bigger battery.
The gas makes the heat, but the blower that pushes warm air through the ducts is a real motor with a real start-up surge — far more than a British combi boiler. Variable-speed (ECM) blowers usually draw less.
Before you rely on it
A furnace blower is a real motor with a start-up surge, and most furnaces are hard-wired with no plug. Some will not light on a station's floating output because they sense the flame through ground. The furnace guide explains all three problems and the safe way to connect one.
The numbers
| Setup | Average draw | Cautious | Typical | Best case |
|---|---|---|---|---|
| 1 × gas furnace, UK 230 V | 308 W | — | — | — |
| 2 × gas furnace, UK 230 V | 608 W | — | — | — |
| 1 × gas furnace, US 120 V | 308 W | — | — | — |
- Usable energy: 178 Wh of the 245 Wh on the box, after chemistry, inverter losses and the reserve.
- To keep it going for a full 24 hours you would need about 10,171 Wh of rated capacity — 41.5× this station.
- Start-up: the gas furnace asks for 1,500 W at switch-on against this station's 600 W peak — not enough.
Buy the EcoFlow RIVER 3
Where to buy
Amazon and approved-programme links are affiliate links; the site may earn a commission at no extra cost to you. Links marked “official site” are untracked. Prices and stock change constantly — check before you buy.
If this is for a power cut
Heating is what a battery does worst. In a power cut, warming people rather than rooms goes much further, and none of this needs a socket.
Without a power station: a 20,000 mAh power bank runs a USB heated throw for about 7 h 24 min. See the power bank numbers.
Hot water bottle and a vacuum flask. Boil water while you still can, keep it hot in a flask, and refill the bottle through the night.
Look for: A bottle made to BS 1970 in the UK, and a flask of a litre or more.
Hand warmers. Air-activated packs give hours of heat with no power at all, and a pocketful helps children and older relatives.
Look for: Long-duration packs, and the expiry date on bulk boxes.
Amazon links are affiliate searches for a type of product, not endorsements of a model; the site may earn a commission at no extra cost to you.
More: How to keep warm in a power cut, and the power cut essentials list (US edition).
What changes the answer
| If instead… | Typical runtime | Change |
|---|---|---|
| The pack is two years old | — | -9% |
| The pack is five years old | — | -21% |
| It is −10 °C outside | — | -16% |
| You run it flat, no reserve | — | +10% |
| You keep 20% back | — | -12% |
If you need it to run longer
These run a gas furnace for at least twice as long as the EcoFlow RIVER 3 does, cheapest first.
| Station | Wh | Typical | Indicative price |
|---|---|---|---|
| DJI Power 500 | 512 | 1 h 12 min | £399 / $449 |
| Jackery Explorer 1000 v2 | 1,070 | 2 h 31 min | £419 / $549 |
| Bluetti AC70 | 768 | 1 h 48 min | £449 / $359 |
| EcoFlow RIVER 2 Pro | 768 | 1 h 48 min | £499 / $549 |
Smaller options that still work
Nothing smaller than the EcoFlow RIVER 3 runs a gas furnace for a useful length of time.
Did this match what you measured?
Nothing is sent anywhere unless analytics is switched on, and no text is collected.