Boilers usually last from 10 to 15 years. So if yours is getting on a bit, it might be time to upgrade to a more energy-efficient model. Take a look at our What’s the right boiler for me? guide to explore your options. If you live in a detached house and replace your old gas boiler with a new A-rated condensing boiler and thermostatic controls, you could save from £260 to £580 a year.