Boilers: How to buy the best boiler Oil boilers
For the estimated four million households not connected to the UK's gas network, an oil-powered central heating system with oil boiler is a key alternative way of heating a home.
There are fewer oil boilers to choose from, but the market still offers a good degree of choice when upgrading your oil heating system. We've reviewed and rated more than twenty models on measures including reliability - use our boiler comparison tool to filter your results by fuel type, so you can browse the full range of oil boilers we've rated.
Oil boilers explained
The average cost of oil heating for a three-bedroom house is around £1,355, compared to anything between £770 and £950 for mains gas, depending on the efficiency of your boiler, and £1,300 for liquid petroleum gas (LPG), the other fuel of choice in the countryside.
An oil central heating system works in a similar way to its gas-powered counterpart, using an oil-fired boiler to heat water, which provides the central heating via radiators and hot water through the taps in your home.
The main difference between the two is that you'll need to have your oil supply delivered and stored in a tank. You can read more about heating oil tanks, prices of heating oil and ordering in our guide to heating oil.
You'll find both heat-only and combination condensing oil boilers on the market. Most oil-fired combination boilers have an internal hot water store to supply domestic hot water rather than the instantaneous heating more common in gas boilers.
We also found that it’s common for the hot water temperature to decline as more water is used. Our home heating systems guide has more information on the pros and cons of an oil central heating system.
Oil boiler maintenance and efficiency
Oil is a more efficient fuel than gas, so you'll get a good return on every unit of energy - but like gas, the price of oil continues to steadily rise. Which? members can find local oil suppliers in their area recommended by other members using Which? Local.
To conform with building regulations, since 1 April 2007 oil-fired boilers must have a Sedbuk efficiency of 86% or more (unless an exception is allowed). In practice, only condensing oil-fired boilers can meet this efficiency requirement. Typically, a new condensing oil-fired boiler will have an efficiency of 92% to 93% compared with 85% for a new non-condensing boiler and 60% to 70% of older systems.
You should choose a professional registered with the Oil Firing Technical Association (Oftec) to install an oil boiler and heating system. Which? Local can also help you find recommended boiler servicing engineers in your area - and it's advisable to get your oil boiler serviced each year.