Q.How can I identify defective kerosene (altered kerosene, impure kerosene)?

FAQ / Laser FF Heater (Direct Vent)

A.You can identify it by color.

Prepare two cups. Pour the water in one cup and kerosene in the other one. Then, put the white paper behind the two cups and compare them. If kerosene has a color, it might be altered kerosene. Altered kerosene has slightly yellow color and smells sour. (Depending on storing condition, the kerosene may become altered even though it does not have a color.) Also, in the case of water-mixed impure kerosene, the water accumulates down and separates with kerosene.