Heating and hot water

Central heating is the most common form of heating in the UK. A single boiler heats up water that is pumped through pipes to radiators throughout the house as well as providing hot water to the kitchen and bathroom taps.

Most boilers run on mains gas, but in areas where mains gas is not available, the boiler could run on oil, electricity, LPG (tank gas), coal or wood. Mains gas is usually the cheapest, and has lower carbon dioxide emissions than other fossil fuels such as oil and LPG. Some boilers also have an electric immersion heater as a backup.

If you have a central heating system, you may want to consider these energy saving improvements:

• Replace your boiler with a newer, more efficient model.
• Fit better controls and use them to make sure your boiler only provides heat where and when you want it.
• Switch to a cheaper or lower carbon fuel or technology. Find out about renewable technologies for generating electricity and heat.
• Make any insulation and draught-proofing improvements that you can.
• Use chemical inhibitors to help maintain central heating system efficiency.

Since 2005, virtually all gas boilers that have been fitted in the UK are more efficient, condensing boilers. Condensing boilers have bigger heat exchangers that recover more heat from the burning gas, making them more efficient.

Your boiler will be a condensing boiler if the following is true:

• The flue is made of plastic. If it is made of metal, it’s unlikely to be a condensing boiler.
• The boiler has a plastic pipe coming out of the bottom, through the wall and into a drain.
• If it is a gas or oil boiler that was installed after 2005.

A regular boiler is more efficient than a combi at producing hot water, but it will lose some heat from the hot water cylinder. Therefore, a combi boiler may be more efficient overall.

Combi boiler

A combi (or combination) boiler provides hot water directly, whenever it is required, and does not need a hot water cylinder. Gas, oil and LPG boilers may be combination.

Regular boiler

A regular boiler provides hot water when the programmer tells it to, and then stores it in a hot water cylinder until it is needed.

Most UK homes that don’t have a boiler and radiators have electric storage heaters. Storage heaters are designed to work with dual rate and other storage heating specific electricity tariffs. These tariffs allow you to charge your heaters during the energy supplier’s cheaper, off-peak period, storing the heat for when you need it.

With a storage heating system, you will likely have a few panel heaters in less used rooms, like your bedroom, and a hot water cylinder heated by one or two immersion heaters for your hot water.

Electric storage heating is more common in flats, rented property, and in homes with no mains gas connection.

Electricity is one of the most expensive fuels per unit in the UK. However, as more renewable technologies generate our electricity, it is becoming low carbon. An insulated home with an efficient, controllable heating system can help reduce how much you spend with an electric heating system, and other options, such as a heat pump, could reduce your running costs further.

Secondary heating refers to the use of individual heaters, such as portable electric heaters, electric towel rails or fixed gas fires, in addition to your central heating or electric storage heaters.

Modern central heating systems are usually more efficient than individual electric heaters, but it can make sense to use an individual heater to heat one space for a limited time.

If you have older, manual electric storage heaters, try to reduce how much you use a boost or convector heater at the top of the storage heater itself. These usually use the more expensive, peak rate tariff so try to only use them if you run out of stored heat.

If you are installing or replacing a fixed (wall-mounted or otherwise) gas heater then you will need to use a Gas Safe Register installer.

You should always use a qualified electrician to fit or replace storage heaters. You can use the Competent Persons Register to find an electrician who is registered with a Government-approved accreditation scheme.

If you want to get a wood burning stove or boiler, the installation must comply with Building Regulations. HETAS is a Government-recognised body which approves biomass appliances and services. You can use the HETAS register to find a trained installer.

Portable heaters can be bought from DIY or home furnishing shops and do not need to be installed by a professional. You can just take them home and use them when you need them.