It’s a sobering thought, but the average lifespan of most domestic gas boilers is around ten to fifteen years.

That period can be lengthened if you have a regular boiler service from a trusted local plumber, (What you need to know about hiring a plumber read here) but if your boiler is reaching the end of its useful life and you’re thinking about replacing it and/or upgrading your heating system, you need to decide what would suit your home, circumstances and price range. Broadly speaking, boilers fall into three main categories.

Combi Boiler

The UK’s most popular choice of boiler, combis differ from conventional boilers in that they provide hot water to your taps on demand. These sealed systems heat the water directly from the mains supply as and when needed, so there’s no necessity for a hot water storage cylinder or a water tank in your roof space. They are quick to install and, taking up less space, are perfect for smaller properties. They also reduce your water heating costs.

The downside of a combi is that it cannot be used with a power shower as it won’t heat the water fast enough to cope with demand. Also, if you use more than one tap simultaneously, the water pressure is reduced. This can be a problem in properties with more than one bathroom.

System Boiler

Unlike combis, system boilers store hot water in a cylinder, meaning that several taps can be run at mains pressure simultaneously. So they’re a good choice for larger homes with more people. Most of the main components are built-in, so installation is quick and easy.

However, a system boiler will run out of hot water if demand is particularly heavy, and its complexity can give rise to problems when it comes to boiler repair.

Conventional Boiler

Nowadays these tend to be purchased only for homes that already have an open-vented heating system; one supplied from a tank in the roof space and thus open to air. A conventional boiler will supply a good flow rate from the taps and cope with a power shower.

The disadvantages of a conventional boiler are that they take up more space, require that the tank be located high enough to supply adequate pressure, and can run out of hot water.

Size Matters

It used to be a rule of thumb to oversize boilers by a third. In our more environmentally aware times this is considered wasteful, so it’s best to buy the boiler that is the right size for your home.

You also need, of course, to consider whether the boiler will fit into the actual physical space where you want it to go, or whether you should find a better location.

Heating engineers or plumbers can help you by producing a heat loss calculation that will take into consideration the size of your home, its level of insulation and airtightness, and your requirements based on the number of bathrooms. Call in a Lincolnshire professional you can trust or figure it out yourself by using a free online calculator such as those on offer at  or . This will help you understand whether the boiler you intend to buy is large enough to heat the entire system efficiently.

Boilers are rated on a scale from A to G, with A as the most energy efficient.

Lastly, bear in mind that your new boiler’s performance can be hampered by a distribution system that is furred up and full of sludge, so it’s a good idea to have your pipework and radiators cleaned out prior to installation.