How long will an EcoFlow DELTA 3 run a gas combi boiler?
About 12 hours — 12 h typically, from 11 h 18 min in the worst case to 12 h 43 min at best. That assumes a gas combi boiler pulling 85 W for 60% of the time (average 51 W), plus the station's 11 W AC mains socket overhead — 62 W in total out of 744 usable watt-hours.
The gas makes the heat, so a battery only has to run the fan, pump and controls. Most boilers are wired into a fused spur rather than a plug, and some will not light on a station’s ungrounded output — read the boiler guide before relying on it.
Before you rely on it
The battery is the easy part. Most boilers are wired into a fused spur with no plug, and some will not light on a station's floating output because they sense the flame through earth. The boiler guide explains both problems and who can fix them.
The numbers
| Setup | Average draw | Cautious | Typical | Best case |
|---|---|---|---|---|
| 1 × gas combi boiler, UK 230 V | 62 W | 11 h 18 min | 12 h | 12 h 43 min |
| 2 × gas combi boiler, UK 230 V | 113 W | 6 h 12 min | 6 h 35 min | 6 h 58 min |
| 1 × gas combi boiler, US 120 V | 62 W | 11 h 18 min | 12 h | 12 h 43 min |
- 1.5 nights of eight hours, or 0.5 days of continuous running.
- Usable energy: 744 Wh of the 1,024 Wh on the box, after chemistry, inverter losses and the reserve.
- To keep it going for a full 24 hours you would need about 2,048 Wh of rated capacity — 2× this station.
- Start-up: the gas combi boiler asks for 85 W at switch-on against this station's 3,600 W peak — comfortable.
Buy the EcoFlow DELTA 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 | 11 h 2 min | -8% |
| The pack is five years old | 9 h 36 min | -20% |
| It is −10 °C outside | 10 h 12 min | -15% |
| You run it flat, no reserve | 13 h 20 min | +11% |
| You keep 20% back | 10 h 40 min | -11% |
If you need it to run longer
These run a gas combi boiler for at least twice as long as the EcoFlow DELTA 3 does, cheapest first.
| Station | Wh | Typical | Indicative price |
|---|---|---|---|
| Dabbsson DBS2300 | 2,330 | 26 h 28 min | £1,499 / $1,599 |
| Bluetti Apex 300 | 2,764 | 29 h 59 min | £1,799 / $1,699 |
| Anker SOLIX F3000 | 3,072 | 33 h 19 min | £1,899 / $1,999 |
| Bluetti AC300 + B300 | 3,072 | 32 h 22 min | £2,499 / $2,699 |
The cheapest step up: Dabbsson DBS2300
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.
Smaller options that still work
| Station | Wh | Typical | Weight | Indicative price |
|---|---|---|---|---|
| Goal Zero Yeti 1000 | 998 | 11 h 42 min | 16 kg | — / $1,200 |
| EcoFlow RIVER 2 Pro | 768 | 9 h 9 min | 7.8 kg | £499 / $549 |
| Bluetti AC70 | 768 | 9 h 9 min | 10.2 kg | £449 / $359 |
| Anker SOLIX C800 Plus | 768 | 9 h 9 min | 10.7 kg | — |
Did this match what you measured?
Nothing is sent anywhere unless analytics is switched on, and no text is collected.