New boilers, priced online and fitted properly

Ten to fifteen years for a modern condensing boiler that is serviced every year, and plenty go longer. What shortens that is sludge in the system, hard-water scale in the heat exchanger and skipped services. That is why every boiler we fit gets a magnetic filter, why we offer a scale reducer on every quote, and why we nag about the annual service.

Not just because of its age. The signs it is time are repairs adding up, parts getting hard to find, a non-condensing boiler burning 20 to 30% more gas than a new one would, pressure that keeps dropping, or a boiler that struggles on cold mornings. If yours is fifteen-plus, out of guarantee and costing you a call-out a year, replacing it is usually the cheaper decision over the next five years. If it is ten years old and behaves itself, keep it and service it.

A combi heats water the moment you open a tap, so there is no cylinder and no tank in the loft, just one box on the wall. A system boiler heats a hot water cylinder, usually in the airing cupboard, but takes its water straight from the mains, so there is still no loft tank. A regular boiler, also called conventional or heat-only, heats a cylinder and is fed from a cold tank in the loft, with the pump outside the boiler. A combi suits most one- and two-bathroom homes; a cylinder suits homes running several showers at once.

It does, and everywhere we cover is hard water. Scale builds up in the heat exchanger and, on a combi, in the plate exchanger that makes your hot water, so the boiler works harder, gets noisier and fails earlier. An inline scale reducer on the cold feed is a £36 option on every combi quote, and we would fit one in our own house.