Most house hold thermostats have a range from 45 degrees to 90 degrees.
And a lot of the set back thermostats have something called "installer preferences" a way of limiting our teenage kids from turning the heat up to 90 and leaving or the air conditioning down to 45, and i suspect your thermostat either was set up like that from the factory and needs adjustment, or its possible that while looking it over it got set that way.
In my own home i us White-Rodgers set back thermostats.
We have used White-Rodgers thermostats for 24 years and while they do compair in price with the Honywell thermostats, the White-Rodgers thermostats are considerably easier to operate and have proved to be much more reliable.
I would use google to find the installation instructions if you dont have have them or find the manufacturers web site for guidence.
Sincerely
Duane
Also you can pm me, if i can be of any help as this is what i do for a living.