What is That Sludge in My Oil Tank?


Have you ever been told that there’s sludge in your oil tank? Or, have you seen the unpleasant substance yourself?  It’s not uncommon to end up with some sort of sludge or thick, viscous “stuff” at the bottom of your heating oil tank, but there are ways to prevent it from building up.

What is Sludge?

When water vapour condenses in the tank, it collects on the interior and causes rust to form. Both water and rust fall into the tank and sink to the bottom to form a layer there. This is a space where microbes or bacteria can grow very well and these microbes actually survive off the oil. As they eat the oil, they break it down and create that dark sediment that is called sludge.

You’ll get sludge in just about every home heating system and it’s impossible to completely prevent it. However, there are a number of ways to ensure it doesn’t actually cause issues with your heating system, including how the tank is designed. The oil for the boiler is taken from a few inches off the bottom of the tank to avoid sucking in that sludge and is filtered to eliminate any particles that may wreak havoc on the heating system.

How to Reduce Sludge

To avoid sludge build-up to the point where it’s actually a problem, use the following methods:

Replace your filters. Every year, you should replace the oil filters to make sure the boiler never receives tainted oil. It will also keep the oil flowing properly through the system.

Fill your oil tank. Generally, it’s accepted that oil tanks should be refilled when they are down to a quarter of a tank of fuel. Not only does this ensure you never run out of oil, but it also prevents the sludge from being sucked into the boiler because it’s the only thing left.

Keep tanks full when not using them. Is it too warm out to heat your home? Now is the time to top off the tank so you have minimal space for water vapour to form. Keep it full when you’re not using the tank.

Add an emulsifier. You can purchase sludge emulsifiers to break down the sludge and spread the particles throughout the remaining oil. Ask your oil provider, though, since some companies use this as a matter of course.

Use high-quality oil. The cheaper the oil, the more likely it is to become sludge. Select your oil provider with great care. Cheap oils are often more contaminated than the more expensive ones, so opt for one that is cleaner to avoid problems.

Are you looking for a better fuel provider? At D&SL Fuels & Lubricants, we offer high-quality, clean fuel with clean combustion. Get your free quote today!


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