Answering light keeps flashing when theres no messages

That might be the Voice Mail Warning Indicator.
On the D1680 and similar handsets, it is reset by:

1. press [menu]
2. scroll down to "Global Setup", press [select]
3. scroll down to "VMWI Reset", press [select]
4. scroll down from "No" to "Yes", press [select]
5. handset will chirp, blinking lamp goes out,
6. press [END]

Other models, check your manual. The model number
is on a small sticker under the battery in the handset --
enter this number at www.manualslib.com to get a free
copy of the User's Manual.
Good luck!