Why Do Oil Tanks Fail?

Internal corrosion is the main cause of aboveground home heating oil tank failure. Water is the primary culprit. Moisture condenses inside all tanks and settles to the bottom. It combines with sediment, bacteria and sulfur from the oil to form a crude acid.

The acid on the tank bottom causes electrolysis, whereby electrons are removed from the steel tank shell. This electrolysis causes focused pitting at random sites on the tank interior, within the area that is covered by the sludge and water. The corrosion pits are often quite small in diameter, which is why tank leaks commonly occur as weeping wet spots or slow drips.

What's the Best Way to Protect Oil Tanks?

You need to deal with the water on the tank bottom. Even with bottom outlet tanks, the sludge and sediment holds moisture, so there is water inside every tank.

The only effective way to protect a tank against internal corrosion is to treat it with a corrosion inhibitor, like TANK-GUARD®, that mixes with the water and sludge - not with the oil. TANK-GUARD® is chemically engineered to fight the electrolysis and corrosion on the tank bottom.

Liquid TANK-GUARD® is formulated specifically for use in fuel oil tanks. It is a concentrate that is heavier than fuel oil. It goes to the bottom of the tank and reacts only with moisture and acids - not with the oil. It neutralizes acidity and protects the inside of the tank bottom against further rusting and corrosive pitting. Annual treatment with TANK-GUARD® can result in longer tank life and reduced service problems.

TANK-GUARD® is safe and is easily installed through the fill pipe once a year during a regular oil delivery or service. If TANK-GUARD® should be carried through the oil line to the burner, it will simply be burned with no harmful consequences.

Remember that the oil is floating on top of the water and sludge. Additives that mix with oil can't have any effect on the tank bottom. Only a chemical that mixes with water can attack the real problem. It's the best preventive medicine for oil tanks.

If you don't treat the water, you are just waiting for the tank to leak.