Combi-boilers are normally installed as a direct replacement of an existing combi-boiler.
They can also replace a heat only or system boiler.
When a combi-boiler replaces a heat only boiler, heating system will have to be upgraded to a sealed system and removing the hot water cylinder as the boiler heats the hot water directly, this also means removing the tanks in the loft space.
All the boilers we install are condensing boilers to recover as much heat as possible.