These pictures, of the inside of the boiler, were taken Jan13/2003, a little over one year after the Fitch Fuel Catalyst unit was installed. The two pictures to the left show the very small amount of soot formation. It was very white and wiped away very easily. The last picture to the right is after a wire brush was passed quickly in and out. It was stated that the whole boiler could be cleaned in less than 1/2 hour. It was plain to see that that there was very very minimal build up inside the boiler, after running this long with the Fitch Fuel Catalyst.