FPPF Chemical Co 00161 16 OZ HOT 4-in-1 Heating Oil Treatment (2 Bottles)

There is always water in fuel oil, but some people downplay the existence of water and the problems it can create. Oil pumped from a cold delivery truck's tank into a warm basement tank causes condensation. Also, water can enter a tank when it is being filled during a rain or snow storm. When water interfaces with fuel oil, algae is produced in the form of sludge. Water pulls the gum from the fuel oil which builds up on the burner parts as varnish. Filters are meant to get rid of dirt. That leaves the water for you to contend with.