hi all i would like to fit some controls to my heating,i have a back boiler with gravity dhw and pumped htg,can i fit a 2 port valve with tank stat in the flow near cylinder,microwswith to fire boiler,and will it be good to fit same before ch pump,controlled via room stat,microswitch to fire back boiler and pump.(incedentally cylinder 1st floor,pump under boards near boiler.thanks for any help