Combi Boiler vs. Separate Boiler and Hot Water

When homeowners compare a combi boiler with a separate boiler plus hot water cylinder (often called “system” or “heat-only” setups), the decision usually comes down to how you use hot water, how much space you have, and your priorities for efficiency and installation cost.

Both options can deliver reliable heating and hot water, but they behave differently—especially when multiple taps are used at once.