The whole system should have been re-piped as a primary\secondary or piped using a hydronic separator. In either case there should be a main circulator that pumps around the primary loop or through the separator that runs when any zone calls. Then there needs to be either circulators or zone valves or both on each zone. Zone valves or circulators can be controlled by single relays, transformers or either Taco's or tekmar's controllers. Wiring the whole thing get's complicated if you have never done it before, for that matter, so does the piping. This is not a homeowner job by any stretch of the imagination. Even guys that have been in the trade for years have problems with mixed systems and controls.