Thank you for your question.
The Graphite inset stove doesn't have a back boiler.
We do sell a number of stoves which are boiler stoves you can find them here. They are separated by the approx number of radiators they can heat, from domestic hot water only right through to stoves that can heat 12 to 15 large radiators.
There is also a section just for inset stoves.
Hope this helps?