Can I use HVO in my oil boiler?

What HVO is

HVO (hydrotreated vegetable oil) is a renewable, diesel-quality fuel made from biomass. For home heating, OFTEC says it should meet the BS EN 15940 standard and come from verifiable, sustainable waste sources such as used cooking oil. OFTEC says that at 100% HVO a heating system's emissions fall by around 88% compared with kerosene.

HVO is made entirely of paraffins and has none of the aromatic compounds found in kerosene. It is less dense than kerosene and gives slightly less heat per litre.

Why a boiler needs converting

OFTEC's HVO handbook says changing from kerosene to HVO requires formal conversion and recommissioning of the installation, because HVO behaves differently:

• older natural rubber seals in pumps and filters can dry out, crack and leak once kerosene's aromatics are gone, so they need replacing;
• flexible oil lines, filters, de-aerators, fire valves and some valves usually need swapping for HVO-compatible parts;
• the burner must be one its maker has approved for HVO and usually needs an HVO nozzle and other new parts, OFTEC recommends replacing older yellow-flame burners, and some suction lines need a wider pipe;
• tanks without a bund should be replaced, and OFTEC strongly recommends never putting HVO into a tank over 20 years old.

This is work for an OFTEC-registered technician, not a DIY job. Do not switch a kerosene system to 100% HVO without this conversion. Never use performance-enhanced HVO sold for vehicles, or HVO with added combustion aids, in any heating system: OFTEC warns these can overfire boilers and cause fires. A converted boiler and tank are labelled as suitable for HVO only.

OFTEC said in September 2026 that HVO could be used as a blend straight away in an existing boiler and tank, but its handbook warns that even HVO mixed into kerosene can quickly cause carbon build-up in vaporising sleeve burners, such as those in AGA-type range cookers. Ask an OFTEC-registered technician before putting any HVO product in your tank.

Cost, tax and availability

Industry research quoted in the government's November 2025 consultation puts the cost of converting a home at around £500. An industry-led trial has used HVO in around 150 oil-heated homes, which OFTEC says has run for five years. Your cost depends on the parts your system needs, and a tank replacement adds more.

HMRC charges HVO the same duty rates as diesel. It can only be fully rebated for heating if it is refined to the kerosene specification and marked with the kerosene marker. Not every supplier delivers HVO to homes, so ask suppliers in your area whether they do, and at what price, before converting.

Where the government stands

As of October 2026 there is no government scheme for HVO in home heating. The Department for Energy Security and Net Zero consulted on alternative clean heating for properties that may not suit heat pumps, from 18 November 2025 to 10 February 2026, and says it is still analysing the responses. OFTEC and UKIFDA are urging the government to respond and then consult on introducing a renewable liquid fuel. In England and Wales, the Boiler Upgrade Scheme pays towards heat pumps and biomass boilers, not HVO conversions.

If you are thinking about it

Start with your boiler maker's guidance and an OFTEC-registered technician, who can tell you whether your boiler and tank can be converted and what parts are needed. Check that a local supplier will deliver HVO before you convert, because a converted system should then stay on HVO. Fueltool does not quote HVO. If you are staying with kerosene, compare heating oil prices for your postcode.