The lilyking 657 115kw boiler stove comes with a built in back boiler which can heat up to 6 radiators the lilyking 657 boiler stove is full of great features such as an external riddling grate secondary combustion to increase efficiency and airwash system to help keep the glass clean this stove offers great value and can really make a difference to your heating bill as an addition to your heating systemairwash systemdual air controlsexternal riddling crate