We have been having problems with our dual zone system, operated by two Simple Comfort 3001 thermostats. When both systems are on, the temperature in one of the zones (typically upstairs when heat is running, downstairs when airconditioning is running) will exceed the limit for that zone, but the system will continue to run such that the temperature is as much as 5 degress higher(heat) or lower(air conditioning) than the limit. The thermostats function properly independently, so I don't think it's a problem with them. HELP!!