Hi Valcan, That was me who mentioned the ceramic heater (small cubical heater). I discovered this by mistake. At shut down time, I pulled the stove pipe off. Capped the smoke outlet, and plugged the bottom of the hopper. I then temporarily stuck the small cubical heater in the ash pit till I had time to properly clean the inside of boiler. When that time finally came, I noticed the heater wasn't running. At closer observation, I realized the heater's dial thermostat (set on low) had shut the heater off. The water temp gauge read about 30*. No rust, No dampness, and no corrosion. It was working so good, I never did clean the boiler that summer. Come time to fire up the boiler again in fall, I pulled the heater from ash pit. The inside of the boiler was as if I never shut down. It worked so good, I purposely did the same thing this last past summer, with GREAT results. This is now my yearly shut down practice for the boiler. As for the metal chimney, and stove pipe; I rinse clean with garden hose. Then spray mixture of baking soda & water. Baking soda & water works GREAT on metal chimney, and stove pipe (Another yearly practice).vulcan wrote:I wasn't happy with the results after the water and baking soda cleaning this past spring either. I have decided when I shut the koker down this spring I will dry vac it then place one of the small ceramic heaters in it for the summer. I saw that previously posted here by someone but can't remember who. It seems like a good idea and probably doesn't use much more power than a light bulb.