Gas system boilers, like heat only boilers, provide heat to radiators and stored hot water cylinders. System boilers are used for both high pressure unvented systems as well as gravity fed systems (with a cold water tank in the loft). System boilers differ from heat only boilers in that they have additional components, such as a water pump, built into the unit rather than being provided separately. As a result they tend to be slightly higher in price but on new installations this is more than offset by ease of installation and not having to buy additional components.
Below we list the popular system 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.