hey guys just wondering is it possible to put back boiler heatin rads only. its not possible to have a cyclinder fitted and was wondering if it was fully pumped and open vented would it be ok
No, absolutely not. If there is a power or pump failure the system is will not dissapate heat from the back boiler unit. You must have a natural gravity circuit from the bb to the boiler and back again.
It will have to be a pretty high attic space as the f & e tank will still have to be above the buffer tank. You will also have to ensure that the ceiling joists are suitably re-inforced to accept the weight of a buffer tank that is full of water. You must also have to have a route for the flow and return to the bb and that the maximum pipe run is 25ft in length (straight) less 0.5m for every 90 bend and 0.3m for every sweeping bend.