Leap has a well-established line of Bosch Gas Boilers that provide flexibility when designing one of its integrated central heating systems. All boilers are condensing boilers, meaning they extract 'latent' heat from their exhaust gases, making them more efficient than standard boilers.
The hiFlow 21e and 26e models are used for domestic hot water heating. This can either be 'direct to faucet' (aka 'instantaneous hot water heating') or as a backup heater for domestic hot water. Working as the backup to a Solargenius system (as opposed to an electric element) is a popular choice.
18kW and 30kW 'System' boilers are used for central heating. The temperature produced is perfect for Leap's hydronic radiators, and can be tempered down to a temperature suitable for underfloor.
Domestic and Cenrtral:
'Combi' boilers supply both central heating water and domestic hot water in one tidy package, and feature an extra heat exchanger and pump. Gas burns and heats the water in the first heat exchanger, which can then either go to the central heating system, or be pumped to the second heat exchanger where it exchanges heat with the domestic hot water.