Heating oil tanks: everything you need to know but were afraid to ask

You won’t find many domestic heating oil tanks in the middle of the city; but off the gas grid oil-fired heating systems are a lot more common.

What is an oil tank?

Unlike domestic gas-fired heating where the gas is delivered on demand; with oil-fired systems a bit more preparation is needed: you need to store your oil in an oil tank.

Types of oil tanks

Oil tanks can be installed above or below the ground. They can be made from steel or plastic and can single skinned, double-skinned or be integrally bunded (catchy!), which in plain English is where you have one tank sitting inside another. If you have a single skinned tank, you would usually have a bund or protective layer around it – oil is not something you want to leak! In the old days this bund was a brick walled area and concrete pad. With integrally plastic bunded tanks things have changed for the better.

How will you know that oil is leaking into the bund? Most new oil tanks have a bund alarm that sounds when there’s a problem. Although this is rare – I’ve never personally come across it.

Safety and oil tanks

The Oil Firing Technical Association – of OFTEC – has detailed guidelines about oil tank installation and safety. If you look at their website, you’ll see they’re really big on avoiding fires!

In a nutshell, they suggest keeping your tank a minimum distance from property boundaries and possible heat sources. Combustible materials such as wooden fences, sheds or building eaves all come under scrutiny. If you can’t keep these minimum distances, then you need fire boards at least 100mm away from the tank itself. You can find the regulations stated in the animation above or you can read all the deets on the OFTEC website here.

Another thing to bear in mind it that the installation of an oil tank has to comply with Building Regs. Just make sure you get an OFTEC registered engineer to do the job, as they know the score and will make sure you have all the certification paperwork you need.

Where to put your oil tank

Heating oil can be attractive to thieves, so you might want to put your tank somewhere you can keep a bit of an eye on it. You could add a security camera, lock or lockable valve and check if you’re covered by household insurance – you might not be. You can also buy an oil theft alarm – these are often supplied with new tanks.

Make sure the oil delivery truck can get to it easily too – the driver needs to be able to park and then reach your fill point with the hose without running a Krypton Factor assault course.

If you have a steel tank, you want to keep it away from guttering or other sources of additional water and away from walls or fences where leaves can gather and potentially corrode your tank.

The tank needs to sit on a strong, level surface of stone, paving or concrete that extends at least 300mm beyond the tank on all sides.

Oil level monitoring

The most common call out for OFTEC engineers is caused by running out of oil. In the old days you periodically checked the level in the oil tank by popping the lid and visually checking. This was updated to a sight glass tube on the outside of the tank. The main problem there was that the sight glass only measured the level when a sprung loaded valve was pressed. (The amount of times I’ve been out to an oil tank that they swear is full…the I press the valve and the level drops to the bottom!)

These days we have devices like a “night watchman”. They use sonar to read the internal oil level and then transmit a signal to an easy to read display plugged into a wall socket. Once the oil gets low, an LED will indicate it’s time to fill up. This is by far the best way of avoiding a cold few days! However, please don’t unplug the receiver from the wall and make sure it’s got a strong signal to the oil tank transmitter in accordance with manufacturer instructions.

Maintaining your oil tank

Make sure you inspect your oil tank every year as part of your annual heating system service along with the oil boiler. It’s also a good idea to keep an eye out yourself to check for rust, cracks or bulges which could lead to a fuel leak. Get all this right, and a domestic oil tank will typically have a life span of about 15-20 years. They may smell though. Sorry!