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Replacing your heating

With over half of your energy bills spent on heating and hot water, it’s important to have an efficient heating system you can control easily. Explore the options for replacing your heating system here.

Did you know that over half of your energy bills are spent on heating and hot water? It’s important to have an efficient heating system that you can control easily to help keep these bills as low as possible.

There are lots of different types of heating systems – from electric heaters to gas boilers and heat pumps to wood-fuelled systems like log burners. So, if it’s time to replace your storage heaters or upgrade your boiler, see what steps you could take to make sure your new heating system is as efficient as possible.

Or, if you’re ready to make the switch to a lower carbon heating system, like a heat pump or biomass stove, you could save yourself even more money on bills in the long-term, at the same time as reducing your carbon emissions.

Replacing electric heaters

It’s estimated that around 10% of London homes have electric heating, with 50% of these using storage heaters. They tend to be more common in flats and rented properties, or those with no connection to the gas network. 

Electric heating is any heating system that uses electricity as its main energy source, including electric storage heaters, electric boilers and underfloor heating. 

What are the benefits of electric heating?

Electric heating systems are fairly inexpensive to install, compared to other heating options like heat pumps, and once they’ve been fitted they require very little maintenance.

If you don’t have central heating, installing electric heaters could be the cheapest option as you won’t need to fit a ‘wet’ system (with plumbing), meaning you’ll keep costs down.

Electric heating – in particular storage heaters – can also be used to heat one room at a time, or can be useful for topping up other heating systems if you need an extra boost on very cold days.

What are the different types of electric heating systems?

There are four main types of electric heating: storage heaters, electric boilers, direct electric heaters and underfloor heating.

  • These are the most common type of electric heating, and the most common type of heating system behind gas and oil boilers in the UK. They’re sometimes referred to as night storage heaters as they’re designed to work with electricity tariffs that supply cheaper electricity at certain times of day, usually overnight.

  • These work like a traditional boiler, using electricity to heat water and send it through radiators or underfloor heating pipes in your home. An electric boiler is often fitted with a hot water cylinder that stores hot water, as well as a special meter, which provides cheaper electricity at certain times of day. This type of system needs to be connected to your home’s plumbing.

  • Electric underfloor heating uses a series of wires installed below or within your flooring to heat a room. It’s often found in bathrooms or shower rooms where it’s used for a short period of time, while the room is occupied. Electric underfloor heating is different from ‘wet’ underfloor heating, which uses hot water in pipes (heated by a boiler or heat pump) under the floor.

What are the different tariffs for electric heating?

Electric storage heaters and electric boilers are designed to work with special tariffs that offer you cheaper rates of electricity at certain times of the day, usually overnight. The most common tariffs are Economy 7 and Economy 10. These ‘Economy’ tariffs relate to a meter that has two or more different electricity rates, offered at different times of the day.

Economy 7 is the most common type of special electricity tariff that’s designed to work with electric storage heaters. You get a cheaper rate for electricity overnight when you charge up your storage heaters. Electric boilers, on the other hand, are commonly paired with Economy 10 meters. These tariffs provide three periods of cheaper rate electricity – one in the morning, afternoon, and evening.

Should I replace my electric heating system?

Electric heating systems have improved a lot since they were first introduced – especially storage heaters, which have been around since the 1960s. If you have very old storage heaters in your home, you should consider upgrading them to new, high heat retention storage heaters, as these will be much more efficient (and cheaper) to run and come with better heating controls. 

If you’ve just purchased a home with an electric heating system, you might want to consider switching to a heat pump, as this will be cheaper to run in the long-term. If you’re not ready to make the switch to a new system, you could consider upgrading to more modern heaters and controls to help you better manage your energy bills. 

You’ll need to use a registered electrician to replace any electric heating system in your home. We recommend finding an installer registered with a trade association, such as the Electrical Contractors’ Association – search their website to find a registered electrician near you. They should give you advice on the size of heater you need for each room. 

Replacing a gas boiler

Gas boilers are the most common type of heating system in the UK, with over 85% of the country’s homes connected to the gas network. But did you know that having an efficient boiler can make a big difference to how much you spend on heating and hot water every year?

Modern boilers are generally condensing boilers, which makes them more efficient than older models. This is because a condensing boiler recovers more of the heat lost in the hot gases that escape up the flue of a boiler. The flue is the pipe used to remove fumes and supply fresh air to the boiler.

If you need to replace or upgrade your boiler, it’s worth considering whether you could switch to a low carbon heating system like a heat pump or biomass boiler. These systems can help you reduce your energy bills in the long-term and will lower your home’s carbon emissions. If you’re not quite ready to make the switch but want to upgrade your boiler, our advice can help you choose the right one for your home.

Are there different types of gas boilers?

There are two main types of gas boiler: a system boiler and a combination, or combi, boiler. 

The main difference between the two is that a system boiler has a separate hot water cylinder that’s used to store hot water once it’s been heated up, while a combi boiler heats hot water on demand, so doesn’t require a hot water cylinder.  

There are several factors to think about when deciding the right boiler for your home. Smaller households using less hot water may be better off installing a combi boiler – as would homes with limited space for a hot water cylinder. However, if you’ve got a big household that uses a lot of hot water every day, or if you’re considering upgrading to a heat pump in the future (as these need a hot water cylinder too), it might be worth installing a system boiler with a hot water cylinder.  

How do I know if my home has a modern condensing boiler?

There are a few ways to work out if you have a modern condensing boiler. If your gas boiler was fitted after 2005, it’s very likely to be a more efficient condensing boiler.

You can also check the flue – if it’s made of plastic, it’s a condensing boiler. It should also have a plastic pipe coming out of the bottom of the boiler, going through the wall and into a drain.

How much does it cost to replace a gas boiler?

While costs will vary, a simple gas boiler replacement with a modern, efficient boiler alongside thermostatic radiator valves will cost around £4,000. 

How much you could save on your energy bills will also vary, depending on how old the boiler you’re replacing is, as well as the size of your home.  

If you live in a semi-detached house and replace an inefficient D-rated boiler with a new A-rated condensing boiler and set of heating controls, you could save around £305 a year on your energy bills.  

Your installer should be registered with Gas Safe – use their website to find an installer near you – and they should also ensure that your new boiler complies with all current building regulations. 

Installing a heat pump

To reach net zero emissions in the UK, we’re going to have to change the way we heat our homes. We will need to phase out heating systems powered by fossil fuels, like oil and gas boilers, and switch to low carbon alternatives like heat pumps.

The UK Government expects that millions of heat pumps will need to be installed in homes across the country in the next 10-15 years. They’re even offering grants in England and Wales to help with the cost of installing a heat pump, under the Boiler Upgrade Scheme.

Many people think that you need a house with a garden  or a modern insulated home to install a heat pump, but recent research has shown that all types of homes are suitable for these low carbon heating systems – from every style and era. So, if you’re ready to make the switch, here’s what you need to know about installing a heat pump.

  • A heat pump is a low carbon heating system that captures heat from outside and transfers it into your home. They’re suitable for many homes, and tens of thousands have already been installed across the UK.

    There are several different types of heat pumps, but the most common in the UK are air source heat pumps and ground source heat pumps. The main difference between the two is where they get their heat from – the air or the ground.

  • A heat pump captures heat from the outside – whether that’s from the air, ground or even water – and moves it into your home, providing you with heating and hot water. It’s powered by electricity and uses around one unit of electricity for every three units of heat it produces, which makes it a very efficient heating system.

    Heat from the air (in an air source heat pump) or the ground (in a ground source heat pump) is absorbed into a fluid, which then passes through a heat exchanger into the heat pump. This then raises the temperature of the fluid (also known as a refrigerant) and transfers that heat to water. This hot water can then be used to heat the rooms in your home via radiators or underfloor heating and can also heat water stored in a hot water cylinder for all your hot water needs.

  • Air source heat pumps are the most common type of heat pump in the UK. While they are suitable for just about every home, including flats, there are a few things you should consider first.

    You’ll need an area outside your home where the outdoor unit can be fitted – either fixed to the wall or placed on the ground. There needs to be some space around it to allow a good flow of air. You’ll also need space inside your home for the hot water cylinder – this is roughly the size of an American style fridge and should fit into a cupboard that measures around 80cm2.

    You’ll also need to consider how you’re going to heat the rooms in your home – either using radiators or underfloor heating. If you don’t currently have radiators or underfloor heating, for example if you’re upgrading your heating system from electric storage heaters, you’ll need to decide which option is best for you.

    If you’re considering a ground source heat pump, the biggest consideration is whether you have enough outdoor space – and access to that space – to install the external element of your heat pump. Most ground source heat pumps use a ground loop laid horizontally, however if space is limited, you could drill vertical boreholes to gather heat (though this is considerably more expensive).

  • The cost of heat pump varies considerably, depending on factors such as the type and size of heat pump, the size of the property, whether it’s a newbuild or an existing property, as well as whether you need to upgrade your radiators or install underfloor heating. 

    An air source heat pump will cost around £15,000, while a ground source heat pump is much more expensive – starting from £24,000 for a horizontal ground loop and rising to £49,000 if you need to dig a borehole in your garden. 

    You should ask for quotes from at least three different installers for any heat pump system to get a better idea of costs. You can also apply for up to £6,000 to help with the cost of installing a heat pump (up to £5,000 for an air source heat pump) through the UK Government’s Boiler Upgrade Scheme. 

  • Running costs for your heat pump will depend on the type of heat pump you have, how it’s been designed and how you operate it. Whether it will save you money on your bills also depends on several factors, such as the heating system you’re replacing, your electricity tariff, how efficient your heat pump is, the design of your central heating system, as well as where you live in the UK.

    As an example, if you live in a typical four-bedroom detached home and replace an old (G-rated) gas boiler with an air source heat pump (and radiator upgrades), you could save an average of £910 a year on your heating bill. You’d save more by replacing old electric storage heaters with an air source heat pump – an average of £1,900 a year.

Installing a biomass system

Biomass is another lower carbon heating alternative to a gas boiler and one that you could consider for your home, especially if you have a local source of wood fuel.

A biomass system burns wood pellets, chips or logs to heat a single room, or to power central heating and hot water boilers. While burning wood, plants or other organic matter does emit carbon dioxide, it’s considerably less than fossil fuels like coal and oil.

There are two main types of biomass heating system: a stove or boiler. A stove burns wooden logs or pellets to heat a single room, while a biomass boiler can burn logs, pellets or chips, and is connected to a central heating and hot water system – like a regular gas boiler.

What are the benefits of biomass?

Biomass tends to be an affordable heating fuel, especially if you have a source of wood nearby (as delivery costs tend to be cheaper). While the price of wood fuel does vary considerably, it’s often cheaper than other heating options.

It’s also a lower carbon option than a gas boiler, as the carbon dioxide emitted when the wood burns is the same amount that was absorbed by the plant during the time it was growing. It’s considered to be a sustainable option if new plants continue to grow in place of those used as biomass fuel.

What’s the difference between chips and pellets and logs?

You can burn logs, chips and pellets in a biomass system. Stoves and boilers that burn logs need to be stoked by hand and you’ll need a lot of logs to heat a whole house. However, they tend to be cheaper than pellets if you have a local source.

Pellets are much easier to use and control than logs, and if you have a pellet fuelled boiler, you can set it to run automatically in a way that’s very similar to a gas boiler. If you have a pellet or chip burner, it’s likely that it uses an automatic feeder to keep adding fuel at regular intervals to your heating system. Chips tend to be used to heat larger buildings.

Are you allowed to burn wood in London?

The majority of London is covered by smoke control areas, but if you’re not sure, you can check with your local borough. Smoke control areas set a limit on how much smoke you can release from a chimney and prevent you from burning fuel that isn’t ‘authorised’ unless you’re using an ‘exempt appliance’. You can find more information about the rules in London on the Mayor’s website.  

While wood is considered an ‘unauthorised’ fuel in smoke control areas, it can be burned in exempt appliances, including certain biomass boilers and stoves. You can search this directory to find exempt appliances in England. You must only use the types of fuel that the manufacturer specifies for your appliance.  

You’ll need to ensure that any biomass heating system you install complies with recent building regulations – the easiest way to do this is to use an installer registered with a competent person scheme, such as the Microgeneration Certification Scheme (MCS). Search the MCS website to find an installer near you or get help choosing a certified biomass heating system. 

How much does a biomass heating system cost?

While costs vary, an automatically fed pellet boiler for an average sized home will cost around £16,000, including installation. You’ll also need to factor in the cost of regular pellet deliveries, which also depend on factors such as the size and method of delivery. If you have space to store several tonnes of pellets, for example, you may be able to order in bulk at a cost of less than £600 per tonne.