Help! There’s Sludge in My Oil Tank!

Here’s what Causes Oil-tank Sludge—and How to Prevent It

You just had your spring maintenance on your heating system, and the tech found signs of an oil sludge problem. Now what? First of all, don’t ignore the warning.

Ignoring a sludge problem can result in your oil storage tank corroding from the inside out and lead to a tank failure, which can be very costly to remediate.

Even before the problem becomes bad enough to corrode your tank, heating oil sludge is the leading culprit of many heating system problems. It’s a thick, black mixture of dirt, rust, and oxidized fuel that can clog filters, forcing your equipment to work harder to provide heat, reducing efficiency—and driving your energy costs up.

Where Does Heating Oil Sludge Come From?

If your heating oil tank sits empty in the warm summer months, condensation forms on the interior walls of the tank. Because water is denser than heating oil, it drips down and sinks to the bottom of the tank, where it becomes an ideal environment for bacteria and other microorganisms to turn it into sediment or sludge that corrodes your tank.

The line that draws oil to your furnace is located several inches above the bottom of the tank to avoid pulling sludge into the supply line. However, when you get a fuel delivery, it can stir up the sludge from the bottom of the tank and it can get drawn into your system. The good news is that you can prevent oil tank sludge.

How to Prevent Tank Sludge

While it’s possible to get rid of sludge, it’s far easier to prevent it. Here are three measures to stop or slow the formation of sludge in your tank.

  1. Get a fill up in the spring. In the winter, your tank doesn’t stay empty long, and condensation is less likely to form in colder temps. But in summer, especially if your tank is outside, condensation forms quickly, which accelerates the growth of sludge-forming bacteria.
  2. Choose a reputable heating oil supplier. Cheap fuel isn’t always a great value. Discount fuel companies commonly offer fuel that is less refined and contains more contaminants.
  3. Get professional heating maintenance every year. The best way to stay on top of a sludge problem is to have a heating system tune-up every year. A heating system tune-up includes a filter change and helps technicians to spot a sludge problem early, before too much damage is done.

Removing Heating Oil Sludge

Over time, some sludge will accumulate in your tank. If enough sludge accumulates, you’ll need to get rid of it. Your best option is working with a waste-oil contractor. They can drain your tank quickly and safely, saving you money on repairs, improving performance and preventing bigger problems.

If your tank is very old, you may want to consider replacing it. Older tanks are made of steel and have varying thicknesses, some with only single-wall construction. They are much more susceptible to corrosion. Newer tanks are made from plastic and fiberglass and are designed to last 50 years or more.

Need to schedule a spring fill up or end of season maintenance? Contact the team at Southville today.