Replacing your ageing boiler with a new one might seem like a big expense at first glance, but in the long game, it’s one of the most purse-friendly, and eco, things you can do.

In fact, swapping an old G-rated (the least energy efficient) boiler for an A-rated (high-efficiency) model could save you around £490 a year on running costs, according to the Energy Saving Trust and based on replacing the boiler and heating controls in a detached house with gas central heating.

“A boiler of 15 years old or more may be wasting as much as 30p-40p of every pound spent on heating our home and water,” says Martyn Bridges, director of technical support at boiler manufacturer Worcester, Bosch Group.

“Updating your heating system to an A-rated condensing boiler could make your system up to 90% efficient, so it’s well worth considering.”

Having the right controls for your central heating system is also important. “I would always recommend fitting thermostatic radiator valves [TRVs], as they offer individual room comfort and save energy by not allowing rooms to overheat,” says Bridges.

“A recent survey indicated that a central heating system with a full set of controls and TRVs could save up to 40% compared to an uncontrolled system.”

One way to waste – but eventually, with some time and thought, to save – heat is through your home’s windows. Replacing single-glazed windows with double or triple-glazed ones (or even fitting secondary glazing) should make your home warmer, quieter and less prone to condensation. You don’t have to buy modern windows – period-style wooden sash windows can be double glazed, for example. UPVC double-glazed sashes, although less eco, are a good money-saving option.

Your home’s loft, which is easy to insulate, and external walls are other big areas of heat loss. Houses built from the 1920s onwards usually have cavity walls and these can be injected with insulation to keep the heat in and cold out. Solid walls let through twice as much heat as cavity walls, but insulating them isn’t so straightforward. The cheapest and easiest option, especially if you’re replastering anyway, is to use insulated plasterboard internally.

While making your home more energy efficient in the basic ways listed above is great, you can go even further down the eco route. You could, for example, install a system for reusing ‘grey’ water, which includes used water from showers and baths, or you could generate your own electricity. This is typically done with a wind turbine or solar panels (different solar panels can be used to heat your home’s water), but remember domestic wind turbines only work well in certain locations.

Solar panels are expensive, but there are ways to cushion the financial blow, such as ‘rent-a-roof’ schemes, which supply the panels free, providing you then give the supplier your income from the Government’s Feed-In Tariffs scheme, which pays you for the electricity you generate. If you buy the panels yourself, you keep the Feed-In Tariffs income.

Another big eco investment is a heat pump, of which there are three varieties; ground, air and water source. Ground source heat pumps extract warmth from the earth, while air source heat pumps take heat from the air outside. They use the heat extracted to heat your home and in some cases, provide hot water. Heat pumps work best in well-insulated homes, so they’re not for all of us, but they should reduce your fuels bills – and who doesn’t want that?