I have a two zone boiler system, one zone is turning on and off when not being called by the thermostat. My furnace is running constantly because of this. I changed the batteries in that thermostat what else can I do before I call someone in?

I would start by unhooking all t-stat wires from both zone valves (make sure to write them down so you can hook them back up correctly). And see what happens. Let us know..

PS. Make sure the power is off the system when dealing with the wiring.