Home Heating

Choosing the right heating system is vital if your home is to be comfortable, energy efficient and economical to run.

Stovax EchoFlame black with floating hearth

Choosing fuels

If you have mains gas, then a gas boiler is usually the cheapest heating option, so if you currently have an oil, LPG or coal boiler then consider getting gas supplied to your home. If there is no gas pipe nearby then this is not an option, but if it’s available just around the corner then it might be worth paying for a new connection to get cheaper fuel.

You could also consider a wood-fuelled or biomass boiler. These burn logs, pellets or chips, and are connected to your central heating and hot water system – and some models can be automatically fed. Installation costs can be high, but if you replaced electric heating with a wood-burning system you could save as much as £800 a year. Under the government’s domestic Renewable Heat Incentive scheme, you could receive quarterly cash payments over seven years if you install, or have already installed, an eligible renewable heating technology.

Stovax Vision Midi T wood burning with optional wall mounting bracket  Stovax Vogue Mid Midline electric with log and pebble fuel effects

Wall-mounted or floor-mounted, stoves can include a back boiler that will contribute to heating the home. These above and in the main image are fires from Stovax.

Boilers

A Baxi boiler

Specifying the correct size for a boiler is crucial, and there are several online guides to calculate your needs. Since 2005 virtually all gas boilers fitted in the UK are more efficient condensing boilers, which have bigger heat exchangers that recover more heat from the burning gas. Sometimes the flue gases get so cool that the water vapour in the gas condenses out (hence the name). When this happens, even more energy is recovered from the condensing vapour and the efficiency gets higher still.

Picture: A boiler from the Baxi range.

Boilers account for around 55% of domestic energy bills, so an efficient boiler can make a big difference. 

Most old gas and oil boilers are regular boilers – they have a separate hot water cylinder to store hot water, rather than providing it directly from the boiler. When you replace your boiler you have a choice of buying a new regular boiler, and keeping your hot-water cylinder, or buying a combi boiler that doesn’t need a cylinder. A regular boiler is more efficient than a combi at producing hot water in the first place, but then some heat is lost from the hot-water cylinder, so a combi may be more efficient overall. The best option for you will depend on several factors. A large family using lots of hot water could be better off with a regular boiler – a smaller household using less may be better off with a combi. A combi boiler doesn’t need a hot-water cylinder, and so requires less space, and many combis are not compatible with solar water heating or cannot use it so effectively.

Government grants are available to help with the cost of installing energy-efficient boilers and central heating systems. Go to government-grants.co.uk for more information. For a list of registered installers visit the Competent Person Register (competentperson.co.uk) or the Scottish and Northern Ireland Plumbing Employers’ Federation (snipef.org). For gas and LPG boilers, the installer must be Gas Safe registered (gassaferegister.co.uk) and for oil boilers use an OFTEC registered installer (oftec.org.uk).


BOILER TYPES

System boilers

System boilers work in conjunction with a storage cylinder which allows several hot water taps to be fed at the same time, making them ideal for larger homes with multiple bathrooms.

They can be connected to either a mains pressure storage cylinder or a more traditional low-pressure, tank-fed cylinder with a cold-water cistern in the loft.

Major individual components, such as the expansion vessel normally sited in the loft, are built in, meaning installation is quicker and less costly. Secondly, the hot water is pumped though the system to the radiators and hot-water cylinder, resulting in a fast response time and more economical running costs.

A system boiler can be installed with a vented system but an unvented, mains-pressure cylinder is worth considering should you wish to boost pressure. Mains gas is the most cost-effective option if you have access to it.

The average cost to install a system boiler is £900 depending on property type, location and the installation work required.

Combi boilers

A combi differs from any other boiler in that it heats water straight from the mains on demand, so you only pay for what you use, and the hot water is delivered at mains pressure. They are best suited to properties of up to four bedrooms and two bathrooms.


Underfloor heating

Underfloor heating plastic water pipesBoilers and underfloor heating are straight-forward options for anyone close to the mains gas network.

Underfloor heating systems are either warm water (wet) systems or electric (dry) systems, and can be fitted in new or refurbished properties, and in single or multiple rooms. The entire floor effectively becomes a giant radiator, providing gentle, evenly distributed background heat and virtually eliminating cold spots, with no need for radiators.

The most common method of fitting underfloor heating is to lay flexible plastic pipework under the floor slab or fixed under a timber floor. Pipes run to a manifold and typically a house will have several circuits, which enables zoned heating areas controlled by thermostats.

Unlike radiators, underfloor heating systems emit no noise and do not need to run at high temperatures.

They can be powered using renewable energy such as ground source heat pumps and solar panels. Although it can be more expensive to install underfloor heating than standard central heating, the day-to-day running costs often prove more economical. Underfloor systems are not designed to provide instant heat control, and the response times to heat up and cool down are far slower. However, they can be programmed to heat around the clock, ensuring a room never drops below a certain temperature.

Solar thermal panels

Solar thermal panels are an affordable and easy to fit option to boost a home’s green credentials and reduce energy bills. Systems such as Worcester’s Greenskies Solar-Lifestyle and Solar-Lito flat panels work alongside both regular and system boilers and can provide up to 60 per cent of hot water requirements.

Worcester Greenskies solar pannels

Worcester’s Greenskies solar panels fitted to a new home.

Flat plate solar panels include a series of copper pipes which collect and circulate solar energy across a level panel. The panels incorporate a series of copper pipes which are filled with an antifreeze solution which absorbs UV energy from diffused or direct sunlight while it circulates around the pipework in the solar collector.

For maximum performance the ideal orientation for solar panels is facing due south at an angle of between 30-45° to horizontal.

A west-facing panel is preferable to east-facing but still the collected energy will be only 10-20 per cent less than optimum. In most cases, a four-square-metre flat panel collector area or 18 tubes will be sufficient for cylinders up to 300 litres which will happily serve the hot water needs of a family of four.

To provide heating and hot water should there not be enough solar gain during the winter months, an alternative source of energy will need to be connected to the solar hot water cylinder (generally an electric immersion heater or a gas or oil-fired boiler).

Heat pumps

Ground source heat pumps use pipes buried in the garden to extract heat from the ground. This is usually used to heat radiators or underfloor heating systems and hot water. Running costs will depend on several factors, including the size of your home and how well insulated it is.

Ground source heat pump installation

Horizontal pipes are laid for a ground source heat pump installation.

Air and water source heat pumps use similar principles to ground source heat pumps to extract heat from air or water instead of the ground. Air source heat pumps can be fitted outside a house and generally perform better at slightly warmer air temperatures.

Integrated Boiler and Heat Pump

Sime’s Murelle Revolution 30 is the first completely integrated boiler and heat pump in a single cased unit. Using a 30 kW Murelle boiler and completely sealed 4kW output heat pump, Sime is targeting it at the new build, social housing and the retrofit renewables markets. It can be installed by any registered Gas Safe installer in a single installation without requiring an additional F-gas-registered installer to be present. The unit, designed to be hung on an inside wall like a conventional boiler, has two inlets, in addition to the flue outlet, to provide heat and hot water. It achieves an average seasonal heating performance of 134%, with an A++ energy rating.

Sime Murelle Revolution30 and contro

The boiler and heat pump work in tandem, with the heat pump operating first, as this makes the largest contribution to energy efficiency. When the external temperature is higher than its minimum set value the heat pump and the boiler will be activated in quick succession. When the set point is reached, the boiler will start to adjust power until the heat requirement is attained and then both of the generators will be extinguished. If the external temperature is higher than 7°C (this value can be re-set), only the heat pump will be activated. The boiler will be activated only when the desired temperature is not achieved by the heat pump on its own.

Stoves

A stove is an enclosed, free-standing device fuelled by logs, briquettes, coal, sustainable wood pellets or smokeless fuels, and will normally require a chimney or flue pipe to operate. Wood-burning stoves are only suitable for burning wood, whereas multi-fuel stoves have an adjustable grate that allows you to burn wood, coal or smokeless fuel. Stoves are usually cleaner and more efficient than open fires, although storage for fuel will still need to be considered.

Eurostove WestFire 37

Before buying, check with the manufacturer which fuels are suitable to burn on your chosen stove. If you want to get a wood-burning stove, 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 (hetas.co.uk) to find a trained installer.

Some models can be connected to a back boiler to heat water and you can buy wood-fired boilers as part of a central heating system.

A high output boiler stove will power a whole house, with a smaller stove just topping up the hot water and/or heating.

Buying and storing logs

The type of wood you burn on your log-burner will affect its performance and heat output. For instance, hardwood and softwood logs burn differently. Hardwoods are any broad-leafed, deciduous trees, such as beech, elm and oak, while softwoods are conifers including cedar and fir.

woodstore

Hardwood is better than softwood as it burns slower. The density of softwood is also around half that of hardwood, which means it burns twice as fast.

Regardless of the wood type it’s essential that logs are dry and seasoned.

This means leaving them exposed to wind and the sun for a year or more before burning. While ‘wet’ logs will burn, much of the energy will be wasted in producing steam.

Freshly cut wood has a moisture content of 65-90%, depending on the species. Exposing the timber to the elements in a wood store where air can circulate through it reduces this content to a much more desirable level. Drying logs in a kiln can reduce this even more, to less than 20%.

The best woods for burning

Apple

Burns slowly with a small flame and produces a pleasant scent.

Ash

Considered the best firewood, it produces a steady flame and strong heat output.

Beech

Burns similar to ash.

Birch

Produces a strong heat output but can burn quite quickly.

Hawthorn

A traditional firewood with a slow burn and strong heat output.

Horse chestnut

Better burnt in woodburning stoves as it can spit. It produces a good flame and strong heat output.

Oak

Its density results in a small flame and a very slow burn.

Robinia

A good burning wood with a slow burn and strong heat output. Can produce an acrid smoke but not a problem in a wood-burner.

Thorn

Steady flame and very strong heat output without producing excess smoke.

Gas fires

Gas fires turn on at the touch of a button and can incorporate a timer and a thermostat. They can be used in smoke-control areas and require no fuel storage space. A gas fire may be installed in an open fireplace, a fire basket or an insert mounted into an existing opening.

Natural gas is the most common fuel, although LPG is an alternative for those without a natural gas supply.

Bottled gas heaters, gas convector heaters and paraffin stoves don’t need flues (chimneys). However, the water vapour they produce can cause condensation which will lead to damp and mould problems if the room is poorly ventilated.

Radiant fires emanate heat from the combustion chamber only and incorporate a glowing back panel to maximise heat output. Convector fires take advantage of a heat exchanger attached to the back of the fire which draws in cold air and sends it into the room as hot air – maximising heat output.

Not every gas fire is suitable for every home.

Brick chimneys will accommodate virtually all gas fires, while prefabricated and precast flues will fit many fires. If no flue pipe or chimney is available, then a power flue or balanced flue may be used.

Electric fires

An electric fire can be stand-alone or wall-mounted, provides instant heat and is suitable for homes not connected to the mains gas network.

Cheap to buy and easy to install and use, electric fires are ideal for smoke-controlled areas.

Some models can even be remote controlled for added convenience.

Most electric fires are fan-assisted and often have several heat settings. Inset electric fires can be fitted into a fireplace opening or secured flat against a wall and are ideal for replacing an old gas or electric fire within an existing fireplace. Wall-hung electric fires have a more modern design than traditional fireplaces and may be positioned anywhere in a room.

Electric stoves

With a design based on the classic wood-burning stove, electric stoves have a realistic flame effect and the fire itself can either be hearth-mounted or positioned on the floor. Unlike a real fire, the brightness and heat can be adjusted.