Just after some advice please, is there any problems with installing a twin coil cylinder (bottom coil connected to solar panel circ and top coil to the boiler circ.) and also incorporating a hot water return loop. I understand most of the twin coil cylinder shave a secondary return connection, but I have heard something about problems with stratification... or the lack of it?? Is this something to do with trying to keep the water circulating at 50degC?
Cheers

Cheers