- Customer showed tech photos of downstairs thermostat reading 63 degrees while set to 68. Thermostat was satisfied at 71 upon arrival. - Confirmed thermostat programming, second stage compressor operation, defrost control, and heat strip operation. Found zone board programmed for gas system and no zone priority. Set the upstairs thermostat to heat and the downstairs secondary; the zone board opened the upstairs and kept the downstairs damper closed, for its 15 min auto changeover. This caused the system to neglect zone 1 and the temperature to drop. Adjusted zone programming to zone 1 priority and confirmed proper operation. Adjusted zone board to electric fan control from gas. System is operating normally at this time. Contractor warranty.