Combi is short for combination boiler, which refers to its ability to supply both central heating and hot water. Unlike System or Regular boilers which rely on a hot water storage cylinder, combi will produce hot water on demand. They are more efficient and they’re also great space-savers as they don’t need a water tank. If you currently have a big unsightly water tank in your basement or cupboard, you’ll be able to get rid of it once you convert your central heating system to combi.
Also the hot water tank no longer limits you as to how much hot water you can have. With a combi you now have an endless on-demand hot water supply and there is no standby energy loss as the hot water is only produced in the amount that is required. Storing water in conventional heating systems means part of the energy evaporates in thin air.
No matter how well the hot water cylinder is insulated, some heat will always escape. With a combination boiler there is no such problem because it heats up the flow of water as and when needed.

Combi boilers prices comparison and reviews of the best selling models for the year of 2019. If you’re not quite sure which combi boiler you should choose for your size house, this article is not going to leave any stone unturned.