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.