What types of central heating are available and how do you get the best use out of them? Here we look at how we heat our homes in the UK.
As we’re deep into winter, how and when we heat our homes is more of a hot topic. It’s a good time to compare energy to find the best deals, to ensure you’re paying a good rate for your increased usage.
It’s also a good time to get into energy saving habits, and to find out the answers to questions such as should you leave your heating on low all day, or use timed bursts?
Here we’re going to the heart of the matter: what kind of central heating is available, how do the systems work, and how can we be the most economical with our heating?
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What are the different types of central heating?
Central heating systems all generate heat from a main source, then distribute the heat by numerous means. Generally speaking, there are four main types:
- Wet systems – by far the most common type
- Warm air systems
- Storage heaters
- District heating systems
We’ll take a look at each in turn.
How does a wet heating system work?
With a wet system, water is heated via a boiler or heat exchanger, which is then pumped around your home via a system of pipes. This serves two purposes: household heating and hot water. As such, the hot water could end up in your radiators; or possibly in a water tank or cylinder – but ultimately coming out of your taps.
There’s a good chance you use this system. In 2021, approximately 90% of UK homes used a wet heating system, although the number using underfloor heating is creeping up.
What are the types of boilers?
Broadly speaking, there are three main types of boilers and wet heating systems commonly in use:
Combi boiler
Most homes are fitted with a combi boiler. These supply hot and cold water on demand, from a sealed central heating system within the boiler. This heats the water when the hot tap or shower is turned on (assuming you don’t have an electric shower). These don’t need additional water tanks, so save on space. However, the hot water it can provide is limited, so it’s recommended for smaller households.
Here are a few top tips for making the most out of your combi boiler:
- You could make the boiler run more efficiently and save money by reducing its flow temperature from 75°C to 60°C. This could save you £65 a year on your bills.
- Reducing the hot water temperature to 42°C could save you a further £17 a year.
- Getting your boiler serviced should cost about £60 – but will make it run more efficiently, and could end up saving you £100s.
Regular / conventional boiler
If you have a hot-water tank upstairs or in your loft and a cold-water tank too (known as a header), this is probably the system you have. The system makes use of gravity to maintain the water pressure. You tend to find these in older homes.
System boilers
Like a combi boiler, this heats the water straight from the mains. But the system also has a hot water tank, where water is stored ahead of use. This makes it more suitable for larger households with multiple bathrooms.
Our top energy saving tip
Whatever type of boiler you have, this top tip could save you up to £100 a year: turn your thermostat down just one degree.
Should I replace my gas boiler?
The majority of central heating systems in the UK have a gas boiler at their heart. While some people do use oil and occasionally LPG boilers, the most common fuel by a country mile is natural gas.
The problem is that this comes hand-in-hand with high CO2 emissions. While figures vary, the most conservative estimate for the household heating’s contribution to CO2 emissions is 14%, with figures as high as 40%. Either way, it’s a large contribution, which is why steps are being taken to gradually phase out UK homes’ dependence on gas boilers.
Government grants of £7,500 are being made available through the Boiler Upgrade Scheme. This is to offset the cost and insulation of either an air source heat pump or – if you have the space for it –
a ground source heat pump.
The amount available has increased in autumn 2023. But whether or not to take up the grant is a bit of a gamble, as costs are expected to come down over time.
How does a warm air heating system work?
Also known as dry systems, here air is drawn in from outside, then heated using a heat pump or gas, for instance. This warm air is then circulated via ducts and vents.
Warm air systems aren’t as common nowadays, although air conditioning in commercial buildings use a similar system. They were more popular in the UK in the 1960s and 70s, but have since all but been replaced by wet systems – which are both more efficient and more comfortable.
How do storage heaters work?
These are electric heaters which store heat in firebricks to be released later. These are generally used to generate heat during off-peak periods (such as if you use an economy 7 meter), which can then be used when energy is more expensive.
While modern storage heaters make better use of space than the bulky old units, they’re still not as common a sight as a system of radiators.
How do district heating systems work?
While not yet that common, district heating systems are growing in popularity, with an estimated 210,000 homes in the UK using this type of system. Heat created centrally is distributed to multiple buildings or properties via large insulated pipes.
Spreading the heating among multiple homes is more efficient, leading to lower carbon emissions. And as properties don’t have individual boilers, for example, the systems also tend to have lower maintenance costs.
The main drawback with district heating systems is they need to be included in new developments, and can’t be retrofitted to properties.
What are the alternatives to central heating?
It may be more efficient in some instances to heat a single room, rather than your entire home. And as time goes on, portable heaters have become smaller, lighter, and more efficient.
The two main options here are fan heaters and oil heaters. Find out which is more cost-effective and likely to work better for you in our fan heater vs oil heater guide.
How to avoid heat loss in your home
The most efficient and economical way to heat a home is to ensure you don’t lose any energy when the heating is on. To make sure you get the most out of your central heating, here are the parts at play:
- Walls. A third of your home’s heat loss is down to the walls, according to the Energy Saving Trust. Most houses built after 1930 have cavity walls, which means there are two walls with a gap between them. Filling this cavity with foam insulation is key to preventing any heat escaping.
- Roof. Insulation for your loft or roof is cheap and easy to install, but makes a big difference when tackling how to reduce your energy bill. Roof insulation from 270mm can be really effective at trapping in all the heat that rises to the top of your house. The thicker the insulation, the more heat loss you’ll prevent. This is a worthwhile investment if you plan on being in a property long-term.
- Windows. As you’d expect, it goes triple > double > single when it comes to the effectiveness of your window glazing at retaining heat. Closing your curtains at night and opening them when it’s sunny is a cheaper and more natural way to keep heat in. You could also buy insulating covers for your curtains.
- Doors. Gaps in and around doors that let in a draught will cause your house to haemorrhage heat. Draught excluders or letterbox bristles are clever ways to prevent this.
- Floor. Filling any gaps between your floor and the skirting board with a simple filler should work a treat. And whacking down a rug or carpet on a hard floor also helps keep the ground toasty.
Essentially, your central heating will work at its best if your household is energy efficient. If it’s not, help may be available. Look into help with your energy bills, including schemes to improve your home’s efficiency. For example, the Great British Insulation Scheme could provide part or fully subsidised insulation to inefficient homes, ensuring that heat is kept in in future.
More ways to save on energy
We have a range of tips for saving on household energy, and also answer the following conundrums:
- Which is cheaper: central heating vs wood-burning stove?
- Dishwasher vs hand washing – which is cheaper?
- Heated airer or dehumidifier – what’s the best way to dry clothes indoors?
- Heated airer or tumble dryer: which is cheaper to dry my washing?
- How much does it cost to run a kettle?
- How much does it cost to run a fan?
- Is it better to heat a room with underfloor heating or a radiator?
- Oven vs microwave – which is cheaper to run?
