The filter icon on my 230b keeps flashing I have changed the filter how do I get it to turn off?

Usually there is a button that says filter, or reset on the stat. Just hold it for 5 seconds it should go away.

Here is your manual. Joshdta is correct. I suggest you keep a copy of this manual for future questions and concerns.

See page 3 on left side for filter note.

http://customer.honeywell.com/techlit/pdf/69-0000s/69-1800.pdf