Yes, it might be cheaper to buy a new printer but as Epson see fit to have built-in redundancy in their printers (me on my soap box!) - sometimes within warranty periods (when they might offer you a re-conditioned printer) - I think you should either try this site:-
http://ssclg.com/epsone.shtml
to download their 'reset' utility
Your printer is mentioned but with the following condition:-
** - NOTE! It is impossible to reset ink counters by software methods on this printer.
Use "ink freezer" function to maintain current ink level and "hot swap" to use refilled old cartridges.
OR use Google to find out how to clean out and reset the 'overflow' tank in your printer. Some sites even give a pictorial tutorial on how to do it (BTW some (?) Canon printers have the same problem but their technicians are taught how to reset the printers).