Kerosene vs Gas Oil for Home Heating: What’s the Difference?

When it comes to choosing the right fuel for home heating in the United Kingdom, the debate around kerosene vs gas oil for home heating is more relevant than ever—especially for off-grid households. With rising energy costs and growing awareness about efficiency and environmental impact, understanding the distinction between these two fuels can help you make a smarter, more cost-effective decision.

At Compass Energy, we’ve spent decades helping homeowners navigate their heating options. This guide breaks down everything you need to know in a clear, practical, and engaging way—without the jargon.

What Is Kerosene Heating Oil?

Kerosene, often referred to as 28-second oil, is the most commonly used heating fuel in UK homes that are not connected to the gas grid.

Key Characteristics:

• Clean-burning fuel with lower sulphur content
• Suitable for modern oil-fired boilers and heaters
• Flows easily even in colder temperatures
• Produces fewer emissions compared to heavier oils

Kerosene is widely preferred for domestic heating due to its efficiency and compatibility with contemporary heating systems.

What Is Gas Oil for Home Heating?

Gas oil, also known as 35-second oil or red diesel, is a heavier fuel traditionally used in commercial, agricultural, and industrial settings. While it can be used for heating, it is less common in residential properties.

Key Characteristics:

• Higher viscosity and thicker composition
• Typically used in older or specialised heating systems
• More economical per litre, but less efficient
• Higher sulphur content and emissions

Gas oil is often chosen where cost is prioritised over efficiency or where older equipment is still in use.

Kerosene vs Gas Oil for Home Heating: Core Differences

Understanding the difference between kerosene and gas oil goes beyond just price. Here’s how they compare across key factors:

1. Efficiency and Performance

Kerosene burns more cleanly and efficiently, making it ideal for modern domestic boilers. Gas oil, being heavier, doesn’t combust as cleanly, which can reduce system efficiency over time.

2. Environmental Impact

Kerosene has significantly lower sulphur content, resulting in fewer harmful emissions. Gas oil produces more pollutants, making it less environmentally friendly.

3. Appliance Compatibility

Most UK home heating systems are specifically designed for kerosene. Using gas oil in these systems can lead to maintenance issues or even damage.

4. Cost Considerations

Gas oil is generally cheaper per litre. However, kerosene’s higher efficiency often offsets the price difference through better heat output and reduced consumption.

5. Storage and Handling

Kerosene is easier to store and handle, especially in colder climates, as it remains fluid at lower temperatures. Gas oil can thicken, leading to operational challenges.

Which Fuel Is Best for UK Homes?

For the majority of households in the UK, kerosene is the clear winner. It aligns better with modern heating systems, delivers improved efficiency, and meets stricter environmental expectations.

Gas oil may still be suitable for:

• Older heating systems not designed for kerosene
• Agricultural or mixed-use properties
• Budget-conscious users with compatible equipment

However, switching to kerosene is often recommended if you’re upgrading your system or aiming for long-term savings and sustainability.

Can You Switch from Gas Oil to Kerosene?

Yes, but it requires professional assessment. Switching fuels isn’t as simple as refilling your tank—you may need:

• Burner adjustments or replacement
• Tank cleaning to remove residue
• System compatibility checks

At Compass Energy, we always recommend consulting a heating engineer before making the switch to ensure safety and efficiency.

Safety Considerations for Both Fuels

Regardless of your choice, safety should always come first:

• Store fuel in approved tanks
• Schedule regular boiler servicing
• Monitor for leaks or unusual odours
• Use certified professionals for installation and maintenance

Proper handling ensures both fuels can be used safely and effectively.

Final Thoughts: Making the Right Choice

Choosing between kerosene vs gas oil for home heating ultimately comes down to your system, budget, and priorities. While gas oil may seem appealing due to its lower upfront cost, kerosene consistently delivers better performance, cleaner combustion, and greater compatibility with UK home heating systems.

For most homeowners, kerosene isn’t just the better option—it’s the smarter long-term investment.

Frequently Asked Questions (FAQ)

1. Is kerosene more expensive than gas oil?

Yes, kerosene usually costs more per litre. However, its higher efficiency often makes it more economical over time.

2. Can I use gas oil in a kerosene boiler?

No, this is not recommended. Using gas oil in a kerosene-specific system can cause damage and reduce efficiency.

3. Why is kerosene called 28-second oil?

The name refers to its viscosity—how quickly it flows under specific conditions. Lower numbers indicate a lighter, more fluid fuel.

4. Is gas oil legal for home heating in the UK?

Yes, but it’s typically restricted to certain uses and properties. Always check current regulations and suitability.

5. Which fuel is more environmentally friendly?

Kerosene is the cleaner option due to its lower sulphur content and reduced emissions.

6. How do I know which fuel my system uses?

Check your boiler manual or consult a qualified heating engineer. Using the wrong fuel can lead to serious issues.