These are commonly asked general questions about using oil for heating or cooking. You’ll find questions on oil-fired boilers, oil storage tanks and oil supply pipes on separate pages.

You may also find additional information from our useful information page or Home Guides page


Will kerosene oil freeze in pipes in winter?

Unless the oil pipe is extremely exposed to wind chill, it is very unlikely that the pipe will become cold enough for the oil to freeze. The type of kerosene supplied for heating and cooking appliances would need to reach minus 39 degrees C before it starts to become cloudy. At this temperature the waxes in the oil start to solidify and make the oil thicker.

If you find a blocked oil supply pipe during the winter months, it is more likely to due to beads of frozen water within the oil line that have expanded and blocked the pipe.

Our best advice would be for an OFTEC registered technician to inspect the oil storage tank for the presence of water. If water is found, the technician will be able to advise you on ways to extract the water and prevent a reoccurrence.

Can oil supply pipes be buried?

Yes, oil supply pipes can be buried with caution. Your local OFTEC registered technician would be able to advise on the most suitable method of installation for the site conditions.

What materials should oil supply pipes be made of?

Your oil supply pipes may be made of:

  • Copper or steel – and any joints made from compression fittings, not solder
  • Plastic – but only approved types of plastic oil supply pipe installed underground

Galvanised pipe is not suitable, and plastic pipes should not be used above ground.

Is it ok to have flexible oil pipes exposed outside of the appliance casing?

No. British Standards require oil supply pipes within a building or outdoors above ground to be made of steel or copper. Unless the flexible oil pipes have an equal degree of fire-rated resistance to that of steel or copper (to be declared by the manufacturer), all flexible pipes should remain concealed within the appliance casing where they are protected by a remote fire valve.

Is there a maximum length for an oil supply pipe?

Generally, there is no limit on the length of oil supply pipe between an oil storage tank and an appliance, so long as the supply pipe is correctly sized and designed for the application. It is possible that your system design may impose a limit.

What is a de-aerator and when do I need one?

A de-aerator is a device which removes left over air from the fuel, promoting enhanced burner efficiency and cleaner combustion. You would typically need one fitted on an oil supply pipe connected to a top outlet tank or where the draw off from a bottom outlet tank is lower than the height of the appliance burner.