What are the acceptable temperature setting ranges for heat and cool modes?
The heating temperature can be set between 40°F and 90°F (4.5°C to 32°C), and the cooling temperature can be set between 50°F and 99°F (10°C to 37°C). If temperature settings do not appear to change, verify that your desired temperatures fall within these acceptable ranges. (Page 11)
From the official Honeywell Pro Th4210D manual, page 11
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