While you wait for answers, we may have found some information which could help you.
Click here for Working Heating Timerreplacing switchmaster midi 3 port valve?
switchmaster?
Sunvic select 107 XLS + Glow worm ultracom hxi?
switchmaster cylinder stat to honeywell cylinder stat?
rReplacing a Switchmaster 3 way motorised valve with a Drayton 3 way valve?
Hot Water System?