Oil tanks store fuel oil for heating systems on commercial and residential properties. They can be above-ground or underground, but even if you can see yours, you may be asking yourself, "How do oil tanks work?" Let's take a closer look at oil tank parts and how they work together to help heat your home.

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Tank

Oil tanks are durable enough to last for years in a variety of different weather conditions. Depending on their size and the energy needs of the building, they can hold anywhere from 250 to 1,000 gallons of heating oil. Tanks are typically either steel or plastic and can be indoors, outdoors or even underground.

There are three different types of tank: single-skin, double-skin or integrally bunded tanks. These categories refer to the exterior of the container, and often to its durability as well. Bunded tanks' design prevents any fuel leaks from escaping into the environment, and can hold 110 percent of the tank's contents. These are often built around the tank, but an integrally bunded model has a bund built right into the exterior of the tank.

Tank leaks don't happen often, but a variety of factors could affect the lifespan and durability of the tank, including the location, the climate, the material of the tank and its age. Nearby vegetation can also affect a tank's lifespan.

Gauge

The gauge on an oil tank works like the gas gauge in your car, letting you know how much oil is in the tank. If the tank is empty, it will usually read E or 0 and will prevent your furnace from working. Try refilling the tank and restarting the furnace. If it doesn't restart after a refill, you may need to call a technician.

You can check to see if your oil gauge is working by paying attention to the levels as you use oil or as you refill the tank. You should also inspect the gauge regularly to make sure it's not cracked or loose.

Vent Pipe

The vent pipe provides ventilation as heating oil moves from your tank into your furnace. The ventilation enables the fuel to run smoothly and evenly without getting hung up in the pipes. It will usually be between one and two inches wide with a mushroom-shaped cap to prevent any debris from falling into your fuel pipes. Underground tanks will often have a vent that will stand between six and 12 inches above the ground, with the same cap.

Vent Whistle

Have you ever accidentally overfilled your car's gas tank? You end up spilling fuel on the ground and the side of your vehicle, which isn't good for the environment or your car's paint. A vent whistle will prevent your tank from overfilling by whistling when your tank is getting close to full. It will sound as soon as you start filling the tank, and will stop whistling when the oil is one to two inches from the top of the tank.

The whistle makes filling your tank safer and reduces the chances of overfilling and spilling oil onto your yard. Depending on your oil company, they may refuse to fill your tank if you don't have a functioning vent whistle.

Fill Pipe

As its name suggests, your oil delivery company uses the fill pipe to fill your tank. It will be secured by a cap to keep water from getting into the oil and can either stand a few inches above the ground or sit flush with the surrounding earth.

Shutoff Valve

Again, as its name suggests, this valve shuts off the flow of oil between your tank and furnace. It is essential to have a functioning shutoff valve on your tank for several different reasons. You don't want oil flowing into the furnace when it's undergoing repairs or routine maintenance. If there's an emergency, you can use the valve to quickly shut off the flow of heating oil to prevent more significant problems.

It's also useful for changing out the tank filter, which we'll discuss in a moment. Turning the shutoff valve will allow you to change the filter without wasting oil as it continues to try to flow into the house.

Tank Filter

You'll usually be able to find the tank filter just after the shutoff valve. Its design helps trap dirt and other particles that might make their way into your tank, preventing them from clogging up your furnace. These filters do fill up after a while, though, and will need replacing. A dirty fuel filter will restrict the flow of oil and make it harder for your furnace to heat your home.

It's a best practice to change your filter once a year, but you may need to change it more often depending on things like the quality of the fuel, the quality of the tank, the quality of the filter itself and how much you're using your furnace.

Fuel Line to Furnace

Fuel lines will run from your oil tank to your furnace, providing it with the oil it needs to heat your home. These lines are easy to damage if you're not careful when walking around your furnace.

Take time to inspect the lines regularly to ensure they're not developing any leaks. If they appear to be damaged or are leaking, get them replaced as soon as possible.

Tank Legs

A fuel tank needs to sit on a level surface, which can be difficult if you don't have a flat spot in your yard. Tank legs help keep the tank level, regardless of the surface where they sit.

Inspect these legs regularly to ensure that they're not bent, rusted or buckling. Make sure that the leg brackets are still securely attached to the tank.