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Reviews > Cook Gear > Stoves > Optimus Nova White Gas Stove > Test Report by S. Nelson

OPTIMUS NOVA+ STOVE
TEST SERIES BY STEVE NELSON

INITIAL REPORT October 21, 2007
FIELD REPORT January 8, 2008
LONG-TERM REPORT April 9, 2008



TESTER INFORMATION

Name: Steve Nelson
Email: nazdarovye at y..oo.com
Age: 47
Location: Kentfield, CA
Gender: M

I've been backpacking since I was a kid, starting in the Adirondacks of upstate New York and in nearby Quebec. I now live in California, backpacking in all four seasons there, with occasional trips back to the east coast and elsewhere. I like hiking fast, and transitioned to lightweight backpacking over the past few years. I also enjoy skiing, snowshoeing, canoeing, and aviation in addition to backpacking, so my gear gets exposed to a wide variety of uses and conditions. As a design and usability expert, I love analyzing and improving products; backpacking provides a rich arena for that.


INITIAL REPORT

October 21, 2007

PRODUCT INFORMATION & SPECIFICATIONS

Manufacturer: Optimus
Year of Manufacture: 2007
Manufacturer's Website: www.optimus.se
Listed Weight: 15 oz (425 g) "with pump"
Measured Weights:
Stove 10.7 oz (300 g)
Pump 4.0 oz (115 g)
Total Base Weight: 14.7 oz (415 g) with the pump
Bottle 3.45 oz (100 g)
Cap .55 oz (15 g)
Windscreen 1.65 oz (45 g)
Tool 1.35 oz (40 g)
Supplies .25 oz (7 g)
Pouch 2.65 oz (75 g)
Grand Total Weight: 24.6 oz (697 g) for the whole kit

Other details: can burn white gas or kerosene with no issues, supports use of diesel and unleaded gasoline with caveats including increased chance of clogging and potential exposure to unhealthy additives

INITIAL IMPRESSIONS

The Nova+ comes packaged as a complete kit includng the stove body (with rounded, folding legs and a metal fuel line with the Powerline control valve and a quick-connect fitting); a metal pump with the mate for the quick-connect on the fuel line; a green 450 ml (15 oz) fuel bottle with a black plastic cap; a multi-wrench with integrated magnet (used to clean the stove's jet by moving a needle from outside the stove); an aluminum windscreen; a spare parts kit (o-rings and lubricant); and an unusual compartmented black nylon pouch with a zipper around three sides plus an open top with a cinch cord. Here is the full kit, laid out next to an architect's scale:

Nova+ in bag


I own the older Nova model and have used it successfully for years, so much about the new Nova+ was familiar. The main stove components exude quality and are all well-made and most are smooth to operate.

One very minor note: the compartments in the nylon pouch seem not quite the right size for the components as provided; in particular, the windscreen is slightly too large to fit in the compartment designated for it, stressing the seams a bit. That said, everything does fit in the pouch with a bit of effort, and it looks to be a fairly convenient, if somewhat heavy, way to carry the stove and its bits. Here's a picture of it packed in its pouch, next to its fuel bottle and the architect's scale:

Nova+ packed in bag


READING THE INSTRUCTIONS

The Nova+ comes with a small, illustrated instruction booklet, as well as an insert giving an additional caution about tightening the stove's valve too far and use of the multitool if it sticks. The instructions cover setup and lighting of the stove, as well as basic troubleshooting, maintenance and use of the included cleaning magnet and tool. The instructions don't cover use of the windscreen or the zippered pouch—I figured out how best to pack the stove and its components into the latter by looking at a picture on the Optimus website.

All instructions are also available—in several languages—for download as PDF files from the website, though on a couple of occasions the website did not respond and could not be contacted by my browser (specifically the Optimus.se site—no problems loading others).

TRYING IT OUT

I gave the stove an initial tryout on our patio, using white gas as the fuel. I filled the fuel bottle up to a bit less than the maximum fill line, screwed in the pump, set up the stove on the ground, and connected the stove to the pump with the quick-connect valve. All of this worked just like it does with the older Nova I own.

The big difference on the Nova+ is the new remote Powerline control valve. I was surprised to discover that this valve works by rotating the entire fuel line. A knurled green plastic lump is fused to the line near the fuel bottle and rotates the line to open and close the valve at the stove body. This also exposed my first issue with the design of the stove: the fuel line has to be quite straight for it to be able to turn and adjust the flame. I fear I'll no longer be able to position the fuel bottle anywhere that is convenient, if that placement bends the line (more on that in a moment).

Lighting the stove was easy—especially given that I own the previous model and this one lights the same way. Pump up the fuel bottle, turn the valve open for a couple of seconds, close it, and light the fuel on the wick under the burner. Wait until it just about goes out, then crank open the valve again and make sure it lights correctly. Here it is priming:

Nova+ during priming


In this case, after priming, the stove lit right up with a beautiful, clean, almost invisible but very strong blue flame.

With the stove lit, and while adjusting the flame, I noticed the next surprise: the burner assembly was tipped off the ground at an angle; a slight bend in the fuel line forced it up as shown in this picture (in which, by the way, the stove is running at full blast):

Nova+ lit and running


Note that the right-hand legs of the stove are about half an inch (1 cm) off the ground. While setting a full pot on this would probably pin it down, I'm concerned about the stove being a bit tippy during lighting and when adjusting the flame (which, in this test, made the stove tip back and forth as I rotated the line to adjust the flame, due to the curvature of the line even at its straightest).

I turned the stove off as per the instructions (again, same as the older Nova): flip the fuel bottle over and let the flame burn out, then disconnect the stove line from the pump without closing the valve. When I disconnected the line from the pump, I was surprised to find a fair bit of residual fuel. I also noted a tiny bit of fuel staining around the pump shaft at the top of the fuel bottle. The former rarely happened, and the latter never, with the older model, so I will keep an eye on this in the future (and also make sure I have let all fuel and pressure bleed out of the line). I disassembled the pump and examined it, and could find no obvious issues that would cause a leak around the pump stem; the leather cup was fully lubricated and I saw no flaws in the threads. Consulting the troubleshooting section of the manual, I discovered that this could be a symptom of a faulty valve in the pump, so I plan to contact the manufacturer at this point for advice and will report back.

In any case, after my test, the stove cooled quickly, and it only took a moment to pack it into the nylon pouch.

SUMMARY

After my initial test, I felt that the Nova+ looked to be like a fine upgrade to the venerable Nova, and I was particularly impressed by the effortless priming and extremely hot, efficient flame the first time I lit it. I had some concerns about the new fuel line and valve design, and looked forward to exploring those while enjoying using this stove extensively in winter conditions.


FIELD REPORT

January 8, 2008

LOCATIONS AND CONDITIONS

Due to issues with the pump and time involved in getting replacements from Optimus, I only took the stove out once during the field test period, using the pump from my older Nova (not the plus model). The one use was in the eastern Sierra, near the entrance to the Ansel Adams Wilderness outside of Bishop, CA. Temperatures were in the 40s F (around 5°C), and conditions were sunny and near calm.

FIELD OBSERVATIONS

I contacted Optimus about the leaky pump noted in my initial report, using an email address I found on their web site. Within about a week, I received a response, which was that I likely had a defective "pump valve" (aka drain valve, as previously guessed). They said that they would send a replacement, and in just over a week, I received an envelope from Sweden containing the valve in a plastic pouch (quite fast, considering where the package originated). Unfortunately, it came with no instructions—so I contacted Optimus once again via email, and within less than a week, received an email noting that the valve should be installed "dry" using the included white washer, and that the original one could be removed using a long screwdriver.

Using a screwdriver as instructed, I attempted to remove the original drain valve; this involved taking out the pump's plunger and inserting the screwdriver down into the pump, fairly blindly, to try to find a small notch on the inside end of the valve. I did eventually get everything lined up right, and discovered that the original pump was on so tight that it would not budge. Eventually, the notch in the original pump failed and part of it broke off as I attempted to loosen it.

Wanting to continue testing without further delay, I pulled out the pump from my older Optimus Nova stove, which I've used for years without problems. It has exactly the same mechanical design as the one on the Nova+; the only difference seems to be that the new pump has a black finish on the knurled aluminum block at its top. Confirming that all worked with the old pump just as it did with new, I decided to keep testing with the old pump while later following up with Optimus on how best to get the new pump working.

My one use of the Nova during this period was to test it with kerosene to boil water in the eastern Sierra Nevada at an elevation of approximately 7500 ft (2290 m). As expected, priming was a little sootier than with white gas, and the stove took a few seconds longer to get to a stable burn, but once stable, the flame was hot and strong, and the water boiled quickly. The Nova+ deals well with kerosene as a fuel. On this trip I also attempted to simmer food on the stove; as expected, this worked well—the Nova+ flame can be adjusted down to quite a low level and it simmers quite usefully. Unlike many expedition stoves I've used, the Nova+ (and older Nova, for that matter), has a full range of adjustability.

I found the Nova+ easy to set up and take down, including deploying its included windscreen. The QuickConnect fitting makes it easy to snap the line into place, and the "flip over the bottle" shutdown procedure means that there's little fuel leakage when disconnecting the line.

However, my earlier concerns about placement of the bottle and needing to avoid bending the valve/fuel line were proven valid in the field; the bottle has to be positioned so that the line is as straight as possible. Even with that, the stiffness of the line tends to tip the stove up off of a leg or two, making it unstable until a heavy (meaning, generally, full of water or other material) pot is set on it.



LONG-TERM REPORT

April 9, 2008

LOCATIONS AND CONDITIONS

I used the stove for five days and four nights on a couple of trips during this period. One was a multi-day trip at Yellowstone National Park in February, with temperatures ranging from 28°F (-2°C) to an incredibly chilly -14°F (-26°C); weather ranged from calm to moderately windy, and there was light snow on one day. Another was an overnight snow camping trip near Butte Lake at Lassen National Park in Northern California, with temperatures ranging from 45°F (7°C) down to 22°F (-6°C), and mild winds with no precipitation.

LONG-TERM OBSERVATIONS

I'll state some important positives upfront: the basic operation and design of this stove are excellent. As with the original Nova I own, it primes easily, burns efficiently with varying types of fuel, and can be adjusted to anything from a light simmer to full-blast snow melting. Its flame and mechanics—with one important exception I'll note in a moment—are strong and reliable, and it's easy to maintain in the field. I find no differences in these fundamental qualities between the Nova+ and its older sibling that I own and have used extensively.

However, the new valve design, in my opinion, does have some issues that need correcting. Let me elaborate:

On the Yellowstone trip, we faced some daunting conditions—extreme cold, in particular. I used the stove primarily to melt snow for water and boil water for preparation of food. However, after the second use, as night was falling, I ran into a problem: I couldn't get the stove's valve to open. Because of the notice that came with the stove noting to never turn it off too tightly, I've been quite careful to turn it off only until there was slight resistance, and I doubted that this was the issue. The effect of the cold should have been to contract metal parts, not expand them, so additional friction due to that seemed unlikely, but possible, depending on which parts were affected.

Whatever the cause, the valve was stuck, and the Nova+'s new valve design—the cable with plastic knob—could not gain enough leverage to open it back up. This was exacerbated by that I couldn't see any way for the multitool to turn the valve, just the brass fitting around it—though a pair of pliers might have been able to do the job. The next day, I set the stove out in the sun, and eventually was able to get the valve to turn; my best guess is that some water from snow melting got onto the valve and froze it in place. Perhaps warming the valve with a lighter would have helped release it the prior day—but that would have been a risky step had there been any leaks, and in any case, there's no way to know if that would have released the valve.

It was later pointed out to me that there is a small dimple in the fuel line/valve where it enters the stove inside the brass fitting, and a small notch on the multitool that can be used to turn the valve tube. The design of the dimple and tool, plus the relatively soft metal of the valve, mean that not a leverage is available, but it could very well have been enough to break open the frozen valve; I'll test this in the future.

After my Yellowtone trip I received a replacement pump in the mail from Optimus' U.S. distributor, Katadyn. They were quick to respond to my email regarding the problems with replacing the drain valve and sent a replacement pump at no cost to me—much appreciated. However, the pump appeared to be a used, refurbished one (much wear on its components; glue and/or varnish stuck to the drain valve at the bottom; and a dirty leather cup inside the pump, including flecks of metal), and was of an older design (no black finish on the block).

While the state of the pump I was sent did not instill full confidence, I took it on my next trip, which was to Lassen National Park in Northern California. I used the stove there with white gas to melt snow for water and to boil water for food and beverage preparation over two days. As before, the stove lit and burned well. The replacement pump, despite its appearance, did seem to function just fine (I had lubricated the leather cup with mineral oil prior to the trip, which it most definitely needed). I still found the valve and line a bit awkward to operate, requiring careful placement of the bottle, but beyond that had no complaints about the operation of the stove, which was an efficient snow melter and boiler throughout the trip.

Nova+ melting snow at Lassen National Park

A few other notes from my long-term use:

The stove is easy to maintain; the multitool has the tools necessary to tighten or adjust all components, and it's easy to clean the jet by waving the tool's magnet underneath the stove. (Doing so while the stove is running, however, may result in the flame going out—do take care.) The pouch that comes with the stove is slightly undersized—I've had to work to cram things into place and zip it up on a few occasions—but otherwise well-designed, and holds all components including the multitool and spare parts. I like the green fuel bottle that came with the stove (from an aesthetic standpoint), and the windscreen is effective and easy to pack down with the stove. The legs worked well with pots ranging in size from just under a quart (.9 l) to 4+ qt (4 l), and materials including stainless steel, aluminum and titanium, providing a stable platform and adequate grip.

LONG-TERM SUMMARY

My overall feelings about the Nova+ are mixed: I love the basic stove design, which I've used for years via the original Nova model (which I happily paid for and from which I have gotten way more than my money's worth). I also like the new aesthetics of the green bottle, green knob, and black coating on stove legs and pump block. I was not overly concerned by the defects in the pump from the stove I was shipped, as Optimus and Katadyn addressed the problems quickly and generously (though I would have preferred to have received a new replacement pump for a new stove, not a refurbished one).

However, I cannot recommend the new valve design as it currently stands—I find it unreliable and problematic. With a few small changes, the new design could be made more reliable, and perhaps even exceed the effectiveness of the original design. Being able to adjust the flame remotely, outisde of a wind screen and away from the flame, would be a useful upgrade if the design can be modified to address the problems of sticking and kinking of the current knob and fuel line.

Perhaps it would be possible to revisit the design of the knob and line to provide additional leverage, and ideally also work while bent at an angle. Another minor improvement would be to change the design of the dimple on the valve and associated spike on the tool to one that uses a more conventional pair of flattened surfaces, which would give more leverage for turning the valve should it stick or freeze. I'll look forward to seeing how the folks at Optimus evolve this design.

Should the Nova+ design be upgraded to address the issues I noted in testing, I would use it in preference to my original Nova. However, at this point I will stick with my original Nova stove, which is the most reliable and effective winter stove of all I've ever used (out of a long list, from many brands). That original Nova model is also still sold by Optimus, with some of the cosmetic changes noted earlier, and I highly recommend it.

My thanks to Backpackgeartest.org and to Optimus and Katadyn for including me in this test.



This report was originally created with the BackpackGearTest.org Report Writer Version 1, then modified by hand thereafter. Copyright 2007-8. All rights reserved.

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