Primus
Primus Ulti Stove System 1.7L
- Weight: 2/10 How much it adds to your pack.
- Fuel use: 5/10 How much fuel it burns to boil a litre in calm air: less fuel to carry.
- Boil speed (calm air): 8/10 How fast the maker says it boils 1 litre in calm air.
Two or three people on winter or high-altitude trips who share one large pot
- Fuel
- Gas
- Weight
- 690 g
- Pot size
- 1.7 L
- Boil 1 L, calm air
- 3:30
- Fuel per litre
- Not published
Packed size 17 cm long and 15.2 cm across Compare with a 2-litre bottle
Shorter than a 2-litre bottle and about one and a half times as wide. Drawn to scale.
Where to buy
Alpinetrek £257.48 In stock. Free delivery. Free delivery from £85. Price includes duties and taxes; choose the 1.7 l size on the page. Delivery time shown: 5-7 working days.
View at shop: AlpinetrekUltralight Outdoor Gear £274.99 In stock. Free delivery. Free tracked UK delivery on all orders. List price £314.99 on its page.
View at shop: Ultralight Outdoor GearPrimus £314.99 In stock. Free delivery. Free delivery over £49, £6 under (Primus UK shipping policy page).
View at shop: PrimusPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Weight
From maker's figures 2/10How much it adds to your pack. 2: A weak point.
Primus gives 690 g (specification table), in the 650 g and over band. Justin Outdoors says it weighs almost 700 g; Ultralight Outdoor Gear lists 713 g without the bag.
Fuel use
Estimate from maker's specs: fuel type (no fuel use figure published) 5/10How much fuel it burns to boil a litre in calm air: less fuel to carry. 5: Does the job. Average for wild-camping gear.
Estimate from maker's specs
Boil speed (calm air)
From maker's figures 8/10How fast the maker says it boils 1 litre in calm air. 8: Clearly better than most.
Primus says 1 litre in 3 min 30 s (210 s): its specification table gives 3:30 without a volume, and its copy for this size says the burner 'boils 1 litre of water in just 3.5 minutes', the same figure as the 1.0 L. That is in the 210-269 s band and right on the line. Justin Outdoors timed 4 min 21 s for 1 litre at about -8 °C with the canister inverted and very little wind.
In short
Good for
- Two or three people on winter or high-altitude trips who share one large pot
- Cold camps: the canister can be inverted, and Justin Outdoors tested it at about -8 °C
- Melting snow or boiling water for freeze-dried meals, not frying
Strengths
- Flameless radiant burner under a heat-exchanger pot; Primus says it is its most windproof stove
- Primus quotes 1 litre in 3 min 30 s
- Justin Outdoors boiled 1 litre in 4 min 21 s at about -8 °C using 14 g of fuel, against 11 min 20 s and 29 g for an MSR WindPro II with a titanium pot
- Remote canister on a hose with an inverted-canister mode for deep cold
- Pots nest: Chris Woollard shows the 1.0 L pot fitting inside the 1.7 L
- Primus sells it for 'high altitudes and extreme cold' and for melting snow, so we mark it winter-ready from Primus's own words
Weaknesses
- 690 g for burner and pot is heavy for solo use
- Only one reviewer has tested this size, so ease has no score; the wind score comes from reviews of the 1.0 L burner
- Chris Woollard's first Ulti, a 1.0 L, melted in use with a Coleman propane-butane canister. Primus replaced it with this 1.7 L, and the updated instructions he shows in the box name only its Power Gas or Winter Gas (propane and isobutane); Primus's page says not to use butane gas
- Primus gives no litres-per-canister figure
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (6)
- Primus: Ulti Stove System 1.7L product page (specification table: weight, boil time, size)
- Justin Outdoors (YouTube): I Test Unbelievable New Winter Camping Gear (Ulti 1.7 L boil test at about -8 °C)
- Chris Woollard (YouTube): Primus Ulti Replacement Review (1.7 L unboxed; his 1.0 L melted with propane-butane gas)
- UKC Gear (Dan Bailey): Primus Ulti Stove System - Finally, a rival to the Reactor? (1.0 L tested)
- GearJunkie (Will Brendza): Primus Ulti Stove 1.0 Review (1.0 L tested)
- Chef Corso (YouTube): The ultimate backpacking stove showdown: MSR Reactor vs Primus Ulti (1.0 L tested)