CB is and has been UL listed for many years now. UL stickers are right on the side. I have had no problems with CB as a company, their dealers or their products. Quite the contrary. I recommend them highly. Also this is from personal experience, not something I heard from a guy who knew a guy that had talked to some other guy. I designed and installed a CB 4436 unit at my ex's house, and it is still in operation. It runs pretty much flawlessly. Their factory people were courteous, informed, spoke English, knew what I was asking about when sizing flat plate Hx and retro-fitting the system into an existing solar hot water sytem and electric hydronic floor heating sytem. They were good at helping with a very unusual design, and one that still works really really well. We had a bad controller unit the first year, and they replaced it under warantee, no problem. They also gave us a free gallon of corrosion inhibitor becasue the boiler had boiled over when the controller failed. They also gave us a new damper door that had banged into a weird position for some reason that we never figured out. They did not quibble, they just replaced anything that went wrong. The unit will be paid for in displaced electric bills by about this time next year. I expect it to last for at least 25 years.
One thing to note about buying an OWB in New England, the Mid Atlantic states, Washington State, Ohio and the like is that soon they will require that you install an OWB that is EPA approved. There are not too many OWB companies out there that are EPA approved. CB has 2 units that are approved, and they are both gassifier units. They are more efficient than their older style OWBs, they burn hotter and they smoke a lot less. Not that the old ones smoke that much, but there has been a HUGE stink in the mid-Atlantic and New England states about OWBs. New York and Ohio are probably the two worst states regarding anti-OWB legislation. At any rate, it is something to consider when buying an OWB in Ohio.
Also another thing to note: it is highly unlikely that you will find a traditional OWB that has a burn time of anything over 24 hours when it gets below about 15 degrees. Many people talk about long burn times, but I have never seen anything over 24 hours myself, in many different systems that I have observed personally. Oregon is rather mild in winter, compared to the midwest and northeast. We got 24+ hour burn times only when temps were above 40 degrees. Typically we loaded the OWB twice a day, and with the least amount of wood that we could get away with becasue they are more efficient with less wood in there. If you fill them full all the time, the wood at the top of the stack starts to turn to charcoal when the damper is closed, and you loose a lot of energy potential out the stack as a reult of charcoaling the wood before it burns. It is a contradiction in a starved-air OWB system that the more wood you load in there for longer burn times, the less efficient they become, and hence they then require more wood for the same amout of heat. We bought the smallest system tht CB had at the time, and it was sized correctly for our needs. We could have paid more and bought a much larger system and gotten longer burn times. However, stuffing a large OWB full and making charcoal is not a very efficient process.