The different boiler fuel types for your central heating Re April 11, 2022

The different boiler fuel types for your central heating

Oil boiler tank

Choosing a new boiler has become slightly more complicated in recent years. With new, more eco-friendly technologies and fuels being developed at an accelerated pace, and a desire to reach the UK government’s goals, there are now a lot of choices of how to heat your home.

Some options aren’t even available to the public yet, but with the rapid development we’ve seen over the last few years, that could change quickly. By 2025, all new-built homes will be using low carbon systems for their heating. For existing properties, grants are available via the Boiler Upgrade Scheme (BUS) to encourage the switch over to more eco-friendly central heating.

So, what are the different boiler fuel types? We’ll go over each one to give you a general idea of their pros and cons.


By far the most used heating source in the UK, the push to switch fuel types stems from the high carbon that gas produces. Heating is responsible for around 14% of carbon emissions in the UK, and gas plays a major role.

Despite this, it remains one of the cheapest options at a current average cost of 4.65p per kWh, set to rise to 7p with the new price cap. As the UK lowers its dependence on gas for heating, it’s expected that this price will rise further. However, even with the gas boiler ban happening in 2025 or as late as 2026, the vast majority of homes will still be using gas for their central heating.

Modern gas boilers are also more energy-efficient than older ones. A new gas boiler can be up to 90% efficient, meaning that switching to a more up-to-date system might be good enough for your needs.

All that said, there is now a conversation to be had about whether or not you should stick with a gas boiler, while before, it was the obvious solution.


If you live off the main grid, it’s quite likely that you use oil to heat your property. Oil has historically been almost as cheap as gas, at 4.82p per kWh, and is a good alternative if you’re simply not attached to the UK’s gas grid.

Like gas, modern boilers are very energy-efficient, and it’s relatively easy to replace an existing boiler.

However, oil is also subject to the nicknamed “gas boiler ban” coming in 2025, meaning that the already low percentage of oil users in the UK (4%) will become even more of a rare breed.

Furthermore, those who currently depend on oil are feeling the pinch as its price was not limited by the energy price cap. Oil prices have risen a staggering 50% in one year, making it an unappealing option for most at the time of writing. If prices do fall, then an efficient, modern oil boiler might be the right upgrade for some.


Pure electric heating is another popular option as it has a wide array of benefits. While an electric boiler doesn’t always mean zero carbon emissions, more energy suppliers are offering 100% renewable electric energy sources to customers.

Since it doesn’t require any gas or oil on the property, it’s generally safer and will generate fewer maintenance costs due to fewer points of failure. An electric boiler also doesn’t have the associated noise that generally accompanies gas or oil boilers, especially older units.

It does come at a cost, however. Currently, they are more expensive per kWh at around 18.9p. With new price caps, this is set to rise to 25-28p, depending on location.

If you have solar panels, you can offset some of this cost by generating your own free electricity during the day. If you’re keen to leave a minimal carbon footprint, the higher price might be worth it.


Another option for those off the grid. Liquid petroleum gas is stored in tanks like oil. The benefits of LPG appear when looking at the space for storage, which is much smaller when compared to oil, lower emissions, and installation cost.

LPG produces 12% fewer emissions on average than oil, meaning it’s the more eco-friendly choice between the two. The cost of installation and maintenance is also generally much lower, often costing less than half that of an oil system.

Over the long term, LPG is more expensive at 6.25 per kWh and will also be phased out of new builds by 2025. There are also less qualified engineers for LPG.

The lower cost of installation and maintenance might be enough to offset the generally higher kilowatt-hour price over a shorter period, and with oil prices at an all-time high, it might even be worth the switch.


Burning wood as a green source of fuel might seem counterintuitive at first, but there’s a good reason it’s more eco-friendly than gas or oil. The plants used as fuel for biomass boilers only release the carbon they absorbed during their lifetime, meaning more can be planted to absorb the same carbon. This is the idea of net-zero emissions. Biomass boilers also have infinitely renewable fuel, unlike fossil fuel boilers.

One hurdle to owning a biomass boiler is the initial price, which can be anywhere from £6,000 to £25,000. The good news is that once installed; it’s cheaper than gas at 4.2p per kWh. It might just be worth the initial investment, especially if eligible for the Boiler Upgrade Scheme.


The ban on gas might sound as if it’s closing a door. However, the real switch might not be as drastic as you think. Hydrogen is a gas that can utilize the same infrastructure and the heating systems for it won’t be too different, either. If the electricity used to create it is generated with 100% renewable energy, then it could be a completely clean source of heating, with its only byproduct being water.

Fully hydrogen boilers aren’t yet available, but the UK is swiftly moving towards wide-scale adoption of them. We’ve written a complete guide about hydrogen.

Solar Water Heating

Solar power can be used for more than generating electricity. Solar Water Heating utilizes a different type of technology than Solar PV, which are the panels you’re probably accustomed to.

It works by capturing infrared light and converting it into heat. It passes through your hot water tank, heating it in the process. It can supply about 90% of your hot water during the summer, even supplying 25% in winter. These percentages are flat removals from your heating bills, saving you an impressive amount year-round. Of course, it’s also completely carbon-free and has no impact on the environment. Matching this with a standard gas boiler will be a net positive for you and the environment.

Price varies on the size and the type of system, but the average is around £3,500-5,000.


A British company, Heat Wayv, has developed a new technology that generates heat much like a normal boiler but using microwaves. It’s stated to be almost 100% efficient, recycling waste energy to be used again. It works pretty much the same as your microwave does in your kitchen but is developed to heat your water and feed into your central heating.

Apart from replacing your boiler, it doesn’t require any other changes to your heating system. It’s also stated to be relatively cheaper than other green heating technologies, at around £3,500. Silent, zero-emissions and maintenance-free, the only downside so far is that it’s not available, with only prototypes being made.

Heat Wayv seems to have its eye on the UK heating market, however, claiming it could reduce the UK’s carbon footprint by 14%. With multiple new green heating systems vying for market control, we might very well be seeing the dawn of how we’ll be heating our homes for decades to come.

Heat Pumps

Heat pumps work by drawing heat directly from the air, ground, or water.

They are considered one of the most efficient forms of heating and are considerably cheaper to run than oil or gas boilers. The upfront price varies depending on what type you get, but none are the cheapest options on the market. Ranging from £7,000 to £35,000, they come into their own when regarding the savings you’ll be making with one installed. By replacing a modern A-rated LPG boiler, you could save £1,400 a year in fuel costs, but the savings might not be that noticeable if you were replacing a modern gas boiler.

You will also want to make sure you have a suitably sized area for the unit. Also, if investing in a ground heat pump, an outside space large enough to house the underground piping.

Air heat pumps are easier to install but generate heat at a slower rate than a traditional boiler. The benefit is they are a zero-emission central heating system, that almost costs the same as gas today, at 5.73p per kWh. They also work best with bigger radiators that have a larger surface area to give off heat.

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