Don't know the worth of the clock but definitely suggest you move it away from the window for starters.  Would suggest you contact a good antique furniture dealer who could tell you more.  Sounds nice.  Is it a good wood case?  How big?
Antique Ansonia Clocks - Company History
Ansonia antique clocks, antique clocks
Looks like it could be worth something from the quick searches I made on the web.
I collect clocks and have at least 48 of them running in my home.  Everything from a 2" mantel clock to a bunch of pendulum clocks to a clock that has bird calls every hour to 3 anniversary clocks.  I guess you could say I'm clock crazy.  And yes, daylight savings time is a pain in the patootie for me so I start a few days ahead.