Oil Combi Boilers

Oil combi boilers provide heating and hot water in one efficient unit. Ideal for off-grid properties without a gas supply, these boilers combine hot water and central heating in a single, compact system - no need for separate tanks or cylinders. Whether you’re upgrading an existing combi oil boiler or fitting out a new install, we stock trusted brands built for long-term reliability. Oil combi boilers are easy to fit, simple to maintain, and perfect for rural homes where space and performance both matter.

Q: What is an oil combi boiler and how does it work?

A: An oil combi boiler (or oil combination boiler) provides heating and hot water on demand, without the need for a separate hot water cylinder. It burns heating oil to heat water directly from the mains as needed - perfect for homes off the gas grid that still want the convenience of a combi setup. As a sealed unit, it’s space-saving and efficient.

Q: What’s the difference between an oil boiler and an oil combi boiler?

A: A standard oil boiler (including heat only and system oil boilers) heats water for storage in a separate cylinder. In contrast, an oil combi boiler delivers instant hot water and heating from a single compact unit, removing the need for a tank. It’s a more streamlined choice for modern or smaller homes.

Q: Do I need a hot water tank with an oil combi boiler?

A: No - oil combi boilers don’t require a hot water tank. They heat water on demand as soon as you turn on a tap, which makes them ideal for homes with limited space or no airing cupboard.

Q: What size oil combi boiler do I need?

A: That depends on your property size and hot water demand. A typical 3-4 bedroom home will often need a 25kW to 35kW oil combi boiler, but it’s best to check with your heating engineer. Oversizing or undersizing your boiler can reduce efficiency and performance.

Q: Are oil combi boilers any good?

A: Modern oil-fired combi boilers are efficient, reliable, and great for homes without mains gas. They’re a great solution if you want the simplicity of a combi system but rely on oil as a fuel source. Look for models with high efficiency ratings and easy servicing.

Q: Can you get external oil combi boilers?

A: Yes - we stock external oil combi boilers designed to be installed outdoors. These come in a weatherproof casing and are ideal if you're short on indoor space. They free up room inside the home while delivering the same heating and hot water performance.

Q: How much is an oil combi boiler?

A: Prices vary depending on the brand, size and features, but you can typically expect to pay around £3000 for a new oil combi boiler (excluding installation). 

Q: What are the pros and cons of oil combi boilers?

A: The pros of oil combi boilers include:

• Compact and space-saving.

• No hot water cylinder needed.

• Ideal for off-grid homes.

• Instant hot water.

• Outdoor models available.

The cons of an oil combi boiler include:

• Requires oil storage tank and regular fuel deliveries.

• Installation costs can be higher than gas boilers.

Q: Can I buy an oil combi boiler online?

A: Yes – you can order oil combi boilers online from JT Atkinson for UK-wide delivery or collection. We stock leading brands and can help you choose the right size or model for your property. Need help? Just get in touch with our team or visit your local branch.