I have a two zoned system the first zone had power to the R (red wire) but not the C (blue) common wire. It obviously runs without the C wire on zone 1 even though the C is connected to C circuit board slot. However upstairs in zone 2 the thermostat shows power to the C (blue) common wire but no power to the R (red) wire. My zone 2 furnace is running no issues with filter, float switch etc. what gives is there a different type of wiring for two zone do I need the R wire on the second zone?
help please
