> glad I own the Coleman. With no pumping necessary, it is easy to set up and get cooking. However, at sub zero temps one time it did not work well. The flame hardly got higher than a simmer. It looked like the can was low on fuel even though it was not.
I see that the 'sub-zero' was actually -19 F (-28 C). Well, that is cold! However, if the Powermax canister had been used correctly (previously) it should still have had some propane it it to pressurise it, as propane boils at -40 F (-40 C), so it should work.
I suggest several possibilities.
1) The canister was low on propane for whatever reason, and this meant the pressure inside the canister was very low. However, this is unlikely.
2) The canister had cooled down a lot further, lowering the pressure. You did mention to not touch the freezing fuel canister?
3) The valve or the jet had got a little blocked in the extreme cold.
4) The canister was not properly attached.
But I don't know which one(s) of these might have been significant in your case.
Going on from here:
You should NOT have wrapped the canister in foam. Instead position it so it warms up from radiation from the stove, and sit it on the foam off the ground. As long as you can keep your hand on the canister it is not too hot. I can be quite adamant about this as I know what the safety test requirements are for the canisters. A cool-to-warm canister is a Good Thing!
IF the valve was gummed up you can usually fix this by getting the canister warm to raise the pressure and then cycling the valve wide open and shut a few times fairly quickly. I have met this problem once with another stove – it is rare but can happen.
If the jet was blocked then a field strip is required. This is a pain, but can be done if you have the tools. I don't think Coleman supply a jet spanner with the Xtreme – which I think is reasonable as I have never had any problems with mine. However, I do usually carry a very small light sheet metal spanner with every stove 'just in case'. This is for the jet. Oh yes – also a bit of very fine spring wire which is fine enough to act as a 'pricker' for the jet. This must be VERY fine – check before you leave. Do NOT force a bigger wire into the jet hole.
How to field strip the Xtreme? Place the base of the stove in the palm of your hand and pull the 'windshield-cup' down with your fingers. It will move a little. Then twist the burner head anti-clockwise – it will unscrew. It may be tight the first time. Watch carefully as you unscrew the burner as the bits can go everywhere! Doing this over a t-shirt or something to catch the bits is a good idea. Then unscrew the jet and hold it up to the light. You should be able to see light through the hole. Clean only IF necessary. Now reassemble – carefully! :-) Practice this once or twice at home first; don't rely on doing it the first time in failing light in bad weather in freezing conditions …
Technique for very advanced users, to be tried OUTSIDE ONLY with NO flames around. When the jet is off, try attaching the canister and cracking the valve open briefly. There should be a whoosh of gas – you will smell it. If there is not then you have a problem with valve or the attachment.
Now, the attachment possibility. This is a known problem, but does not always happen. Even Coleman have heard about it, but they can't reproduce it in the lab.
There is a little O-ring on the spigot on the valve (have a look). This presses on the top of the nipple on the canister, and gets compressed to make a seal. Never try to use the stove without this O-ring!!!
In extreme cold it can be difficult to push the canister against the valve hard enough (before you twist it) to get a proper attachment. Known problem. I sometimes suspect the O-ring of being frozen solid, but I don't KNOW.
If the O-ring is not sufficiently compressed the central spigot on the valve assembly does not get pushed far enough into the nipple on the canister. It HAS to be pushed in to open the valve in there. If it is not pushed in far enough the valve may be only partially opened, or not opened at all. I know people have had this problem.
If you suspect this is happening, disassemble and warm the canister and the valve inside your clothing, then try reassembling the valve onto the canister, with a determined squeeze.
I would be interested in whether the stove worked OK when you got back home. Test?
Cheers
Roger Caffin