Around 1.5 million UK homes use oil heating, primarily in rural areas without mains gas. If you're deciding between oil and gas — or considering switching — here's how they compare on every relevant dimension.
Fuel cost comparison
Gas (2025 price cap): approximately 7p/kWh. Oil (kerosene, 2025 average): approximately 6–8p/kWh depending on market and when you buy. Oil prices fluctuate significantly more than regulated gas prices — buying in summer when demand is low typically saves 10–20%.
Efficiency
Modern condensing oil boilers achieve up to 97% net efficiency — actually marginally higher than the best gas boilers. Both are A-rated and both make an excellent choice from a pure efficiency standpoint.
Installation and infrastructure
Gas: requires mains gas connection (most urban and suburban properties). Oil: requires an oil tank on your property (typically 1,000–2,500 litre bunded tank). Oil installation is typically £1,000–£2,500 more expensive due to tank requirements.
Annual servicing
Oil boiler annual service: typically £100–£130 (more intensive than gas — burner nozzle replacement included). Gas boiler service: £79–£90. Oil certification: OFTEC (Oil Firing Technical Association) registration required.
Environmental
Both produce CO₂. Oil has a slightly higher carbon content per kWh than natural gas. Both are fossil fuels subject to future policy pressure. Heat pumps are the low-carbon alternative for both fuel types.
Verdict
On mains gas: gas boiler wins on convenience and infrastructure cost. Off-grid: oil is typically the best fossil fuel alternative, though LPG and heat pumps are also worth considering.