My 02 cents on the Wallas. It's the perfect solution for heating/cooking on a C-Dory...when it works. It'll often fail when you really need it. Returning it for service is expensive and time consuming. Most problems are fuel-related.
My suggestion: Service it yourself.
Get out your digital camera. In the comfort of your home or shop, disassemble the burner.Take lots of pictures from every angle (index and label all the fasteners if you like). When you do you'll see the glow primer and the fuel vaporizer(wick). Replacing either/both is easy(my replcement wick kit comes with a special hex wrench). Remove any carbon deposits with Scotch Brite, emory cloth, or sandpaper. Scan also recommends blowing out the fuel line from the pump end to remove any chance of recontamination. Reassemble and your done.
Now that you've seen how easy it is you'll want to carry a spare wick and glow plug on the boat. You'll also need whatever tools you used (spanner(s), phillips screwdriver, side-cutters or scissors for the zip ties), several zip ties, and fresh fuel. Remember all those pictures you took ? Copies of the best ones will help guide you if you get lost. Next time you're out on the water and your stove quits, instead of simply freezing and cursing you'll be ready.
In under an hour you should be able to remove, service, and replace your Wallas. It can be worked on atop your dinette table.