Furnace Oil have Viscosity of 1500 Sec Redwood No. 1 at 100 Deg F with a fall in temperature this viscosity goes further up making oil to flow extremly difficult. To meet this demand tank suction heaters have been designed. These heaters are installed at little above the tank bottom. The beauty of the heater is that it does not heat entire tank filled with oil it only heates the oil that flows through the heater thus cutting down the kilowatt(KW) rating which otherwise may require to heat entire oil tank. The operation is smooth and safe.