A build-up of sludge in your heating oil tank is not great news! It can lead to significant problems if left to fester and not addressed, potentially affecting both the performance and longevity of your oil-fired central heating system.
As well as reducing efficiency, a build-up of sludge can clog pipework, damage or corrode your system leading to increased maintenance costs and even system failure, and potentially shorten the lifespan of your heating oil boiler and tank if the problem is not addressed. Not to mention the environmental impact of increased emissions and poor air quality due to poor combustion!
Prevention is always better than cure, so in this blog, we’re going to take a look at good tank management and maintenance, and what you can do to prevent the build-up of sludge in your heating oil tank.
So firstly, what is sludge?
It's a dark, gooey substance that builds up over time and settles at the bottom of a heating oil tank. It’s a mix of dirt and debris, rust and corrosion particles from the inside of the tank itself, asphaltenes which are sticky residues that form when heating oil breaks down, bacteria and fungi, and water which promotes microbial growth. Microorganisms flourish in the damp, dark heating oil tank environment, producing waste products that accumulate at the bottom of the tank.
Sludge can form through sedimentation where particles settle at the bottom of the tank over time, through oxidation where the heating oil reacts with oxygen (more likely when your tank is not full), and microbial activity. Then when your tank is refilled, sludge can get disturbed, mixed with the new fuel, and fed through to your boiler.
What are the signs I’ve got sludge in my tank?
You may have noticed that your heating system is less effective than usual – or that you’re using more fuel than expected. This could be a sign of sludge in your tank, which could be clogging the oil filters and nozzles, and reducing the flow of oil to your boiler.
Maybe you’ve noticed unexpected noises coming from your system. Spluttering or banging sounds can be a sign of sludge as it obstructs the fuel supply causing the system to work harder. And if you’re having to change the oil filter more frequently, this could be due to sludge clogging the filter.
If you suspect that you have sludge in your tank, an OFTEC registered heating oil engineer will be able to take a sample from the bottom of the tank and confirm if there’s presence of sludge.
Regular maintenance and tank inspections
As part of your annual boiler service, your fuel storage tank, fuel supply pipework and all ancillary fuel supply components should be visually inspected, as well as the tank dip-tested to determine if any water contamination is present. Your heating oil engineer will report any observations and advise on action to be taken.
Routine inspections can identify problems so they can be addressed before they become too severe. In addition to your annual service, inspect your tank on a regular basis yourself, and look for signs of physical damage such as rust or corrosion, and cracks, for heating oil leaks, and check the supporting structure is in a safe condition. And changing the fuel filter regularly will help maintain a clean fuel flow.
If you have any concerns, contact your local OFTEC registered technician who will be able to advise on how to remove any sludge from your tank, or assist if you've spotted physical damage and may need a new oil tank.
Water Management
Water promotes microbial growth, as well as contributes to rust and corrosion inside your tank, so the problem of sludge can be aggravated when there’s water present in a tank. It’s important, therefore, to do what you can to prevent water from getting into your tank.
There are two main ways in which water can get into your tank, the first being through rainwater ingress. This could be due to a badly fitting tank lid, so the first thing to do if you suspect you have water your tank is to ensure all lids and caps fit securely. Also, check for corroded seals, a split in the tank itself, or a damaged vent.
The second way that water can get into a tank is through the build-up of condensation. It’s more common for this to happen in spring and summertime when the weather starts to warm up and your heating oil tank's internal temperature is lower than the outside temperature, causing condensation to form.
Whilst a few water droplets are harmless, as water accumulates over time it can damage your entire heating system, costing you money and leaving you without heating. Check out our recent article to find out how to prevent water in your oil tank and how to remove it.
Additives
Using additives that are designed to break down sludge in your tank can help keep your fuel system clean. There are a number of different ones available, some of which are intended for oil central heating systems and other which are more specifically designed, for instance those for oil fired range cookers such as AGA’s.
Additives keep your heating system running efficiently whilst preventing a build-up of sludge in your tank so your fuel remains at it best and doesn’t cause any long-term damage to your central heating boiler. They also reduce corrosion in your tank, with a dispersant that gradually clears away any existing sludge.
Our Premium Heating Oil is regular kerosene with an additive already added.
Not only does it prevent the build-up of sludge, Premium Heating Oil is also cleaner burning, up to 15% more efficient, and more economical than regular kerosene. Available to purchase online, or as one of the benefits of our Premium Package*, it reduces boiler breakdown and servicing problems too.
Keep your tank topped up
Did you know that an empty heating oil tank can promote the build-up of condensation? A nearly empty tank is a breeding ground for sludge, whereas keeping your tank topped up minimises the amount of air inside and reduces the chance of condensation forming. The Northern Energy Automatic Refilling Service keeps your tank topped up, and provides the peace of mind that you’ll never run out of heating oil, providing convenience and peace of mind.
What should I do if there’s sludge in my tank?
Oil tank cleaning should be carried out by a professional, qualified technician so contact your OFTEC registered heating oil engineer.
Regular servicing shouldn’t be overlooked as it can increase the working lifespan of your tank. Of course, summertime is the ideal time, and we would recommend you clean your fuel tank at least once a year.
So as you can see, the presence of sludge can cause additional strain. and wear and tear on pumps, valves and other moving parts, cause blockages in fuel lines, and cause corrosion inside the tank itself. Professional cleaning by an OFTEC registered oil heating engineer to remove sludge will ensure the longevity of your tank. By staying vigilant and conducting regular maintenance, the good news is you can detect and manage sludge to ensure you have an efficient and reliable heating oil system.