Oil Tank Outlet Position

Photograph of Carbery, Diamond and Harlequin Oil Tank on an orange background

For decades, Heating Oil Tanks in Great Britain and Ireland have been supplied with an outlet positioned towards the bottom of the tank. However, Top Outlet Heating Oil Tanks are becoming more prevalent and are now offered by most British and Irish Heating Oil Tank manufacturers.


In contrast to the UK and Republic of Ireland, Top Outlet Tanks have been an industry norm in mainland Europe and North America for decades. Their popularity is in part due to their reduced risk of oil pollution. Disconnect the fuel supply line from a Bottom Outlet Oil Tank and the result will be a potentially catastrophic discharge of oil to the environment. But disconnect the oil supply line from a Top Outlet Heating Oil Tank equipped with an anti-siphon valve and the oil will stay where it should… inside the tank.

Integrated Top Outlet Systems

Many Top Outlet Tanks today incorporate integrated outlet systems. These contain everything required for a standard domestic heating oil tank installation, pre-fitted to the tank, helping reduce installation time and cost. The best known of these systems is perhaps Atkinson Equipment’s ‘TankTop’ system. Dependent upon model and manufacturer, these extra features may include:

  • An isolation valve which allows the supply of oil from the tank to be discontinued by pressing a button or pulling a lever;

  • An anti-siphon valve to ensure that should the the oil supply line become disconnected or damaged, stored fuel does not drain from the tank;

  • A fuel filter to remove residual particulates and contaminants, maintaining fuel quality and reducing the risk of boiler breakdown;

  • A floating suction line which draws oil from just below the surface to reduce the risk of water contamination;

  • An oil line connection point to allow the oil supply line to be connected to the tank.


Top Outlet Tanks are compatible with most modern oil-fired appliances incorporating a pressure jet burner – that’s almost every boiler on sale today in the UK and Republic of Ireland. Additionally, Top Outlet Tanks are suitable for use with many range cookers too.

Installation Considerations

When choosing or specifying a Top Outlet Heating Oil Tank, there are a number of considerations to be aware of:

  • Older designs of oil-fired cookers which utilise an old-fashioned vapourising burner will still require a Bottom Outlet Oil Tank, unless an Oil Lifter is fitted to the supply line;

  • At most Top Outlet installations, it is recommended a De-Aerator (e.g. a Tiger Loop) device is fitted to the oil supply line. Further guidance can be found in OFTEC Technical Instruction Book 3;

  • Whereas 10mm diameter oil supply line can be fitted to almost any Bottom Outlet Oil Tank installation, top outlet installations are especially sensitive to oil line diameter. Further guidance, information and sizing advice can be found in OFTEC Technical Instruction Book 3.  

At most Heating Oil storage installations today, there is no good reason not to fit a Top Outlet Heating Oil Tank. However, your storage tank technician can provide definite advice on the suitability of a top outlet tank at your premises.Click here to find your local Technician registered with the Oil Firing Technical Association (OFTEC) in the UK, Republic of Ireland, Channel Islands and Isle of Man.

Queries? Questions?

You’re very welcome to contact us. You can call us on 01789 632 151 in the UK, Channel Islands and Isle of Man, or 01 5268 642 from the Republic of Ireland. You can also e-mail hello@fueltank.store. We’re open weekdays from 9am to 5pm - excluding Bank and Public Holidays and look forward to taking your call.

Photograph of Carbery, Diamond and Harlequin Oil Tanks on an orange background with click to view call to action