I recently had a loft conversion completed in a bungalow and as a result need to incorporate a pressurised sytem, However the plumber that carried out the work did not remove the solid fuel back boiler. As a result the water in the boiler becomes warm each time i switch on the oil fired heating. I have spoken to a friend who has advised me to drain the back boiler and isolate it. Can anyone point me in the right direction as to how to do this.