Oil Heating Systems: The Complete Guide

What Is Heating Oil?

Heating oil (kerosene, sometimes called 28-second oil or C2 grade) is a refined petroleum product used to fuel oil-fired boilers. It is the most common heating fuel for the estimated 1.7 million UK homes not connected to the mains gas network, particularly in rural areas.

How Does an Oil Heating System Work?

An oil boiler works similarly to a gas boiler, except it burns kerosene rather than gas. Oil is stored in a tank on your property — typically between 1,000 and 2,500 litres — and fed to the boiler via a supply pipe. Modern oil boilers are condensing models, achieving efficiencies of over 90%.

Storage Tanks

Your oil storage tank is a critical part of the system. Tanks are made from plastic (single-skin or bunded double-skin) or steel. Bunded tanks — a tank within a tank — are strongly recommended and required in certain locations, as they prevent oil spills from contaminating soil and groundwater. Tanks should be inspected annually.

Running and Maintenance Costs

Oil prices fluctuate with global markets. An average three-bedroom home uses approximately 1,500–2,000 litres per year. Buying in bulk during summer, when prices are typically lower, can reduce costs.

Annual servicing by an OFTEC-registered engineer is essential for safety and efficiency. An oil boiler service includes checking the burner, heat exchanger, nozzle, electrodes, and flue — similar to a gas service but with oil-specific components.

Switching from Oil

Many oil-heated properties are good candidates for air source heat pumps, particularly as they are often rural with larger properties and gardens. The Boiler Upgrade Scheme grant of £7,500 applies to oil-heated properties switching to a heat pump.

OFTEC Registration

Oil boiler work must be carried out by OFTEC-registered engineers. Halo Heating holds the relevant registrations and serves rural Surrey properties. Call 01483 676108 for advice on oil heating systems and alternatives.