Putting up with an old boiler is something lots of us do, but fitting a new one has significant benefits, especially with colder weather on the horizon, says Julia Gray

IF your home has an old boiler, it's easy to put off changing it because it will be expensive, but old boilers are costly to run. A boiler that's 15 years old or more is only around 60-70 per cent efficient, meaning that 30p-40p of every pound spent on heating and hot water is wasted. Many old boilers also have a standing pilot light, which can cost around £50-£60 a year to keep alight.

REPLACE IT NOW

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If an old boiler goes wrong, it may not be possible or cost-effective to repair it, and if this happens when it's cold, replacing it is urgent, which can be more inconvenient and expensive than if you'd planned it.

Summer and early autumn are great times to schedule a boiler replacement because you don't need the heating on and you may be on holiday while the work's being done.

It's also a good idea to replace the rest of the central heating system if it's decades old, including the radiators, radiator valves, and pipework, for a number of reasons.

SPACE-SAVING BENEFIT

Many old boilers are large floor-standing ones that are out of place in a modern home.

Boilers like this can usually be replaced by a much smaller, wall-mounted model, which frees up space.

In most homes, the boiler's in the kitchen or utility room, so one designed to fit in a wall unit is ideal because it's small and can be hidden away out of sight.

WHICH TYPE?

The main types of boiler are regular, system and combi.

"Regular boilers require more space than combi or system boilers, as they often need an expansion tank in the loft, and are suitable for homes with more than two bathrooms and where hot-water usage is high but water pressure is low," says Martyn Bridges of boiler manufacturer Worcester (worcester-bosch.co.uk).

"System boilers have most of the major components of the heating and hot-water system built in, making them more efficient and less space consuming, as there is no need for a tank in the loft.

They are connected to either a mains-pressure hot-water-storage cylinder or a more traditional low-pressure, tank-fed cylinder."

Combis are really popular, mainly because they don't need a separate cylinder or tank, which saves space and money, and they heat water on demand, but combis aren't always the answer.

Larger homes with multiple outlets, such as taps, baths and showers, can be more suited to a boiler with a cylinder. With a new installation, this is typically a system boiler and unvented (mains-pressure) cylinder - cylinders come in different sizes to suit different hot-water needs, and a new cylinder should have a fast reheat time.

Combis can struggle with more than one outlet being used at the same time, so if you're having a shower and someone turns on a tap, water may be diverted away from the shower, although some combis are better able to cope with this - a good heating engineer will be able to advise you.