Boiler upgrades

When a boiler upgrade makes sense

Not every home is ready for a heat pump. For those that aren't yet, replacing an old boiler with a correctly sized modern condensing boiler cuts gas use and makes the heating more reliable.

Common signs it is time: the boiler is more than 10 to 15 years old, it needs repairs every winter, parts are getting hard to find, the heating is uneven around the house, or your gas bills keep rising for no obvious reason.

Combi, system or regular boiler?

A combi boiler heats water on demand and needs no hot water cylinder. It suits smaller homes with one bathroom. A system boiler works with a hot water cylinder but no tanks in the loft, and suits homes with more than one bathroom. A regular boiler, sometimes called heat-only, works with a cylinder and loft tanks and is common in older homes.

We recommend a type based on how many bathrooms you have, how much hot water you use at once and the space available, not on which boiler is easiest to fit.

Why correct sizing matters

Oversized boilers are common. A boiler that is too big switches on and off frequently, wears faster and spends less time running at its most efficient. We size the heating side to your home's heat loss and, for a combi, the hot water side to the flow your household needs.

We also set the flow temperature so the boiler runs in condensing mode, where it recovers heat that would otherwise go up the flue. Many boilers are installed and left at a temperature that stops this happening.

Clean system, filter and controls

A new boiler on a dirty system won't last. Where the old system has built up sludge, we clean it with a power flush or chemical clean, and we fit a magnetic filter to catch debris from then on.

In England, new gas boilers must meet minimum efficiency standards and be fitted with time and temperature controls, and a combi boiler also needs an extra energy-saving measure such as weather compensation or smart controls with automation and optimisation. We fit controls that meet those rules and that you will find easy to use.

Gas safety, paperwork and warranty

By law, gas work must be carried out by a Gas Safe registered engineer. You can check any engineer's ID card on the Gas Safe Register. Every boiler we fit is Gas Safe commissioned, and the installation is notified for building regulations so you receive a compliance certificate.

We register the manufacturer warranty for you. Warranties of up to 10 years are available, and they normally depend on the boiler being serviced every year.

Thinking about a heat pump later?

If you might switch to a heat pump in a few years, tell us at survey. Choices made now, such as larger radiators, a suitable hot water cylinder and running the system at a lower flow temperature, can make that later move cheaper and simpler.