I just got off the phone with Karl from Scan Marine. I told him I had a few questions for him. I told him I had been using the Wallas stove / heater for 4 years and have had no problems. I asked if it was OK to leave the heater control wide open with the lid closed for a long time. He said how long are you talking about. I told him 3 or 4 hours and he said no problem. Also I asked if it was a problem when you open the lid and you can see a red tint on the left hand burner, again no problem. Also, was it a good idea to leave the stove temp. control wide open when shutting it down, again he said it was a good idea to keep it from sooting up. Finally I asked him about fuel. I told him the first year I used diesel and noticed some residue in the bottom of the tank at the end of the season. I then switched to K-1 kerosene and have had no problems since. I also added Stabil to the K-1 and it has stayed clear for 6 months so far. I asked about Klean Heat and his comment was to use diesel or K-1. He did not know anything about Klean Heat but thought that K-1 was a fine fuel for the stove. I also asked about the lubrication of the stove with the different fuels and he said that their are no moving parts that require lubrication. His final advice was if the stove works fine don't do anything until I have a problem. I'm sure most of this is common knowledge amount C-dory owners but it made me feel better.