Environmental pollution and solid residues left over by the oil refining
process are the main causes of unwanted deposits at the bottom of
the fuel tank.
Accumulation of such deposits at the bottom of the tank may grow up
to the level of the supply pipe, which would in turn cause damage
to the burner. It can also cause erosion to the tank itself, in which
case the tank may require replacement.
For all the above reasons, it is necessary that the fuel tank
be cleaned during the summer months when its content is at a low level.