08/01/2025
What should I do if I find water in my oil tank? Answered and Solved.
Finding water in your oil tank is a common problem. If you think you have water in your oil tank, there are several things you should do to prevent the issue from getting worse and causing irreversible damage. Understanding how water enters your tank and why it is a problem is the best way to prevent contamination and know how to respond if you discover water in your oil tank.
How does water get into your oil tank?
Once you know how water can get into your oil tank, it will be easy to spot the signs and prevent it from happening. Water can find its way into your oil tank in a number of ways, and can be due to physical damage, ageing or even manufacturing faults. Some of these ways include rainwater getting into loose or poorly fitted filter caps, poorly fitted or damaged vents, and fluctuations in temperature, which can cause condensation build-up within your tank.
Why is water in your tank a problem?
Water in your tank can cause all sorts of problems; it can affect the longevity of your tank, the everyday running of your appliances and, therefore, the effectiveness of your heating system.
If water is left in the tank for too long, it will cause corrosion, which then creates issues such as a failing system and splits, bulges or cracks in your tank, further leading to leakages and failures. Corrosion also creates the perfect environment for bacteria to grow, which can then contribute to water contamination. This mess then builds up in your tank, becoming what is better known as sludge. Sludge in your oil tank can cause lots more problems. Similar to corrosion, water creates rust when it comes into contact with metal, which can cause an oil tank’s integrity to decrease as it is abrasive to the oil tank parts and equipment.
In winter, the water that has contaminated your tank and is now sitting at the bottom can also freeze, blocking the pipes. Water can also freeze if it gets in the oil, creating hard particles that clog fuel filters, enhance corrosion, and wear out the fuel systems.
Can you prevent water from getting into your oil tank?
There are several steps you can take to help prevent the risk of water contamination in your oil tank.
1. Checking your tank regularly
Having annual oil tank inspections and checking your tank yourself regularly can help prevent water from entering. Checking for cracks, splits, and bulges can prevent minor damage from turning into water contamination.
2. Keep it full
Another way to prevent oil tank contamination is to keep your oil tank topped up to full as often as possible. In summer, when the temperature fluctuates, condensation can form in the gap of air between the tank and your oil level; keeping your oil tank full prevents this.
3. Consider the positioning
Before installing your tank, consider its positioning and how that can reduce your risk of oil tank contamination. Putting your tank in a sheltered place or under a roof or shed can stop rain or snow from getting into your oil tank, therefore preventing the risk of water getting into your oil tank.
4. Clear the area
If your oil tank is in a location with densely populated vegetation, water can easily drip off of trees or bushes and into it. Removing these or simply installing your tank away from these types of risks can ensure its dryness and therefore longevity.
5. Install a bunded oil tank
Having a bunded oil tank can help prevent water from getting inside and contaminating your oil. The aim of the second skin is to act as a containment area, catching oil. If water is somehow dripping into your tank and into the secondary skin, though it is preventing water from getting into your main tank, you must drain it to prevent overflowing in the occasion of an oil spill.
What do you do if you find water in your oil tank?
If you think there is water in your oil tank, you need to act immediately. There are three main steps in this situation: Test for water, Remove the water, and Dispose of the water. There are different extremes to this situation, and if it is very obvious that your oil tank is highly contaminated, you should call an OFTEC Technician for emergency services.
1. Test for water
Water detection paste is one of the simplest ways to check for water in your oil tank at home. To use the paste, dip a long stick into it and carefully put the stick into the tank until it reaches the bottom. It’s essential to reach the bottom because this will also help you determine the water level in your oil tank. Keep the stick in place for about 30 seconds to 1 minute. If water is present, the paste will change colour during this time. Water detection paste is available in red and green, with the specific colour change being detailed in the instructions.
If you get a positive water test result, it is important to immediately shut off your appliances attached to the tank, as it can harm them and cause more damage.
2. Remove the water
When it comes to removing the water from your oil tank, we strongly recommend hiring a professional technician, especially if you believe there is a lot of water in your tank or if you can see the water contamination is due to a damaged oil tank. When water contamination is minimal, it is possible you can remove the water yourself, but it is important to remember that water contamination could be the symptom of a much larger problem.
Water absorbent tool
Placing a water-absorbent tool in your tank, such as a water-absorbing sock or sponge, will instantly absorb any water contamination, preventing the issue from turning into a bigger one.
Valve
Older steel tanks have sludge valves at the bottom, where you can drain water from the container, as the water will sit at the bottom of the tank.
Pumps
Plastic and newer metal tank models don’t have valves at the bottom, but a hand pump can remove small amounts of water from oil tanks.
3. Dispose of the water
Water extracted from your oil tank must be disposed of safely, as it is contaminated; never pour this water down the drain. Instead, take it to a local waste disposal site that has a designated waste oil collection tank specifically for the proper disposal of contaminated water.
Contact your local council:
Check with your local authority to find out the correct disposal method for oil-contaminated water in your area.
Professional help for large amounts:
If your oil tank contains a significant amount of water, it’s best to contact a professional oil tank engineer to safely remove and dispose of it.
Do not flush your drain:
Water from an oil tank is considered contaminated and should never be flushed down a drain.
For oil tank emergencies, such as finding water in your oil tank, contact a member of our team on 01638 598175.
FAQ’s:
Help! I have an underground oil tank. What happens if water gets in it?
Removing water from an underground oil tank is more complex than from an above-ground tank due to access challenges, safety concerns, and potential environmental risks. The process involves draining the oil, separating water from the oil using specialised equipment, and cleaning out any sludge or contaminants. Accessing the tank may require excavation, and professionals must ensure the tank is not corroded or leaking. Water must be disposed of properly, and the tank and fuel lines are typically inspected for damage. Underground tanks are more prone to rust and leaks, and the removal process may involve additional steps like soil remediation if corrosion has occurred. Regular maintenance, such as installing a water drain valve, can help prevent future issues.
Can I remove the water from my oil tank by myself?
It is possible to remove water from your oil tank, provided it is minimal. There are three methods you can use to remove water from your tank yourself.
- Water absorbent tool – Placing a water-absorbent tool in your tank, such as a sock or sponge, will instantly absorb any water contamination.
- Valve – Sludge valves are located at the bottom of some tanks, where you can drain water from the container.
- Pumps – Hand pumps can remove small amounts of water from oil tanks.
Though it is possible to remove small amounts of water from your tank, seek a professional for anything more than what can be absorbed by a stock or any water contamination that has clearly occurred due to physical damage to the tank.
