Combination boilers, also known as combi boilers, heat hot water as you need it. They do not use a separate hot water cylinder. They are ideal where hot water needs are limited. They are particularly suited for flats and small houses where there is only one bathroom/shower room. The system uses mains water pressure, so there are no tanks in the loft.
The negative to a combination boiler is that the flow of hot water is slower than for a system that provides stored hot water. So the power output of the boiler is driven by the hot water requirements rather than the central heating needs. To have a reasonable level of hot water flow the boiler output has to be in a range of 24kW-30kW rather than 15-20kW for a system with a hot water storage tank.
Below we list the popular combi boiler options by power output in kW and then brand. Note that the prices are for the boiler only and do not include the flue. They are also typical prices and do not reflect any price promotions with a specific plumbers merchant or retailer. On occasions, manufacturers offer promotional packages which include the flue.
If you want an indication of what you may pay for a boiler replacement including installation then use our replacement boiler cost online calculator. You can then compare any quotations from installers with this guideline estimate.