I was without the Aqua-Hot in our RV for almost 2 weeks while traveling to Anchorage Alaska. It started to blow black smoke while in Windsor Colorado and a day or two later quit working altogether. The shops in Calgary could not fit me into their schedules so I had to wait until reaching Anchorage. They worked on the unit, replaced the Websato Control Module, $800, replaced the burner nozzle, etc. over three hours of shop labor, total bill was well over $1200. Two months later while staying in Fairbanks, the Aqua-Hot diesel burner stated blowing black smoke again but this time much worse. It was so much that it set off the smoke alarm I have in my front run electrical bay on the same side of the coach that the Aqua-Hot exhaust is located. After returning back to the lower 48, I had Roger Berke of Sacramento look at the Webasto diesel burner and he found many parts that were well worn and needing replacing along with a very old style burner nozzle. The combustion chamber was also choked up with carbon chunks. Needless to say, after another almost $600 of well needed parts, the burner is now in tip top shape. The so called Aqua-Hot trained technicians at Karen's RV service really don't know what they are doing and do not have a clue when it comes to maintaining an Aqua-Hot system. I will NEVER go back to them again. If when in Alaska and I have a Webasto burner problem, I will send the unit to Roger Berke in Sacramento for his expert rebuilding service. He is one of the BEST Aqua-Hot service technicians in the country. Very poor and expensive for what they did which was basically nothing. I contacted them directly after having the unit worked on and fully repaired by Roger Berke in Sacramento CA. I asked them for an explanation of their poor Aqua Service and told them what had to be done to get the unit working correctly. All they said was to return to Anchorage so they could see what I was talking about. Sure, I am going to drive 3000 miles so they can tell me sorry, it's not their problem. I will NEVER go to them for anything, even supplies. I will mail order if necessary while in Alaska.