How To Detect Water in Your Fuel Tank

Water in your fuel tank can spell disaster if it’s not sorted. Water contamination can lead to a whole host of problems including microbial growth, diesel bug, and tank erosion, so it’s important to address it as soon as you’re able. 

Thankfully, it’s fairly simple to test for water yourself, and even easier to get a professional out to test for you. A professional can also perform a fuel polishing service to remove contaminants from the fuel, leaving it in optimal condition. 

Are you interested in learning how to detect water in fuel? We’ll explain what causes water contamination, why you should test your fuel, and how to test for water in this post.

Causes of water in fuel tanks

There are a number of reasons that lead to water contaminating your fuel. 

Damaged and old tanks

If your tank is aged and suffering from deterioration, or damage by nature, an accident, or even vandals, then there is a risk water will get in.

Severe weather

Flash floods and heavy storms can result in excess water that may infiltrate your fuel storage tanks. This can happen in various ways, including condensation caused by rapid temperature changes and storming. A rise in temperature causes water droplets to form inside the tanks through condensation.

Unsealed or open filler caps

If the cap has been left open then the fuel is bared to the elements. Equally, a broken seal allows water to seep in and contaminate the fuel. 

Fueling process

On rare occasions, water can get into a tank during the fueling process, possibly if water happens to be found within the fuel pump itself.

What happens if water gets into the fuel?

When water meets fuel, it creates the ideal breeding ground for bacteria. Bacteria in your fuel, known as microbial contamination, release acid. This acid will cause the corrosion of the tank, the fuel filters, and the fuel lines, allowing for even more contamination. The acid will also result in a sludge-like substance that will settle at the bottom of the tank. 

Corrosion is caused by rust, created by water within your tanks. As this begins inside the tank, you won’t know anything is wrong until it is possibly too late. This is why it’s crucial to schedule regular oil and tank maintenance so you can catch these problems early. Rust will cause abrasive wear to any iron or steel surfaces within the tank, and also results in sediment and bacteria build-up.

Water freezes at 0°, so if there’s water in your tank, it’ll cause damage when the temperatures drop very low. Ice crystals form when water freezes, which can expand in hairline cracks, slow fuel flow and block filters, and cause abrasive damage to equipment and surfaces. 

Why should I test my tank for water?

Water in fuel causes all of the above-mentioned issues: corrosion, microbial contamination, abrasive wear, and the consequences that come with them. These will eventually lead to breakdowns and damage in your engines and systems because of contaminated fuel use. 

Testing for water is incredibly important as it allows you to get ahead of the problem before it worsens. You’ll have the time to schedule a fuel polishing service and potential tank replacements or repairs, saving you a lot of trouble, and money, in the future. 

How to test your fuel for water

Schedule routine fuel maintenance checks and ensure water testing is on the maintenance list.

To test your tanks for water yourself, use a water detection paste. There are many pastes on the market, so you will be able to find one to suit your needs. The paste works by turning a different colour when it comes into contact with water.

First, cover a long piece of weighted string or a stick in the paste. Next, lower it into the tank until you feel it hit the bottom. Wait for 30 seconds, then slowly bring the string or stick back up.

If there is water in your tank then the paste on your instrument will have changed colour, typically towards the bottom as water is heavier than oil. The amount of colour change on your instrument also indicates how much water sits at the bottom of your tank.

If you don’t feel comfortable testing fuel yourself or would rather be certain of the results, contact a professional.

They will use advanced equipment to test your fuel for all contaminants, including water, and then advise on the next steps. It may be that your fuel needs polishing and your tank needs a clean. It could be that your oil needs replacing if it’s too contaminated. There are several outcomes, and a professional will know exactly which route to take.

Schedule a fuel service with Fuelsource

To arrange for a professional to visit you at your site and test your fuel for contaminants like water, give us a call. We’ll organise for an expert to perform the service to give you complete peace of mind. If tank cleaning, repairing, or replacing must follow the test, or your fuel must be polished, we can arrange those services for you too. 

As industry professionals, you can trust us to answer any questions you may have regarding fuel, fuel services, and fuel deliveries. Our friendly, experienced team is on hand to help, so give us a call on 0207 846 0255 or use our simple online form to get a quote.