Our pick of the best combi boilers in 2026

Originally published 27 January 2020, fully updated 20 August 2026. The picks below are the ranges our own Gas Safe engineers fit and stand behind today, with the prices we actually charge.

Combi boilers are not the sort of thing you think about until yours needs replacing, and every brand claims to be the best. Our view after thirty-plus years of fitting and repairing them across Yorkshire: the best combi boiler is the one sized correctly for your home, fitted by an accredited installer, and backed by a warranty long enough to matter. Here is what we would put in our own houses.

How combi boilers work

A combi boiler is a water heater and a central heating boiler in one. It heats water directly from the mains when you turn on a tap, so there is no need for a hot water storage cylinder or a cold water tank in the roof.

The benefits of combi boilers

• Cost effective to run compared to other boiler types
• More energy efficient as water is heated instantly rather than stored
• Space-saving with no cylinder or feed tank
• Hot water at mains pressure, so a powerful shower without a separate pump

1. Ideal Logic, the value pick

The Logic is the boiler we recommend when the budget is the deciding factor and the home is a typical two-to-three-bedroom house. It is straightforward, dependable, and cheap to look after because parts are plentiful. We supply and fit the Ideal Logic combi from £1,695, which is the lowest installed price on our list.

2. Worcester Bosch Greenstar, the all-rounder

The Greenstar range is the one we fit most. Build quality and parts support are the draw, and as Worcester Bosch accredited installers our registered installs carry an extended warranty. Supplied and fitted from £1,895.

3. Vaillant ecoTEC, the long-warranty pick

Vaillant’s ecoTEC combis are quiet, efficient and well made, and the range scales from compact models for smaller homes up to outputs that will run a large family house. We are Vaillant Advance installers, so a registered ecoTEC install carries up to a 10-year warranty, the longest cover on this list. Fitted from £2,095.

What about the other brands?

We service and repair every major make: Baxi, Glow-worm, Viessmann, Potterton, Ferroli, Alpha and the rest. Owning one is not a problem, and our Baxi service and repair page covers the questions we get most. But when we are choosing what to fit new, the three ranges above are where our engineers’ money goes.

Getting the size right matters more than the badge

An oversized boiler short-cycles and wastes gas; an undersized one struggles on a winter morning with two showers running. The right output depends on your radiators, bathrooms and mains flow rate, which is why we survey before we quote. As a rule of thumb, a small terrace needs far less boiler than a four-bedroom detached with two bathrooms, and nobody should be sold a 40kW combi for a two-bedroom flat.

Not sure a combi is even the right type? Our combi vs system boiler guide covers when a cylinder still makes sense, and what a new boiler costs in Yorkshire breaks the prices down properly.

When you are ready, the 60-second fixed-price quote tells you exactly what your home needs, surveyed and priced with no salesman and no “starts from”.