Dirty tubes kill efficiency and no matter what type of fuel is used, soot will quickly accumulate in boiler fire tubes. As much as 1/8" of soot can build up on tubes in only two weeks. This buildup reduces boiler tube efficiency and wastes dollars. Soot on boiler tubes has five times the insulating value of asbestos. The heat transfer loss in a dirty boiler tubes rises tremendously as the layer of soot builds up. Boiler efficiency can be monitored through stack temperature readings. For every 40°F rise in stack temperature, fuel consumption increases by 1%. An increase in stack temperature is an indication of dirty tubes and a signal to clean the boiler tubes with Goodway tube cleaner.