Checked both furnaces and thermostats there was no codes on either furnace. Started and tested both several times and they started properly. Checked the program on both thermostats. The 1st fl was set to - less than 90% when it is a 90% 2 stage furnace. Changed the setting to more than 90%. The 2nd fl was set to single stage heat, the furnace is a 2 stage 90% furnace. With the very cold weather early in the morning, the 2nd floor was not keeping up and the cold air was falling down to the 1st floor. The thermostat downstairs was also reading 14% humidity which will make the room feel cold. Recommend installing a humidifier.