I've been scanning some documents into PDFs. The first few went OK, but when I attempted a longer document I got a message around the fifteenth page that "This product is warming up". This was followed by a warning that the job had been interrupted, and I was given a choice to discard, edit or save the job so far - adding more pages to the job wasn't an option. So I had to save the document as two installments, MyDocument_pp01-15.pdf and MyDocument_pp16-23.pdf. AFAIK there is no option in Windows to collate pdfs.
A quick search indicates I'm not the first Epson customer to experience this problem.
NB: my scanner is an XP-225. (Are all Epson scanners named after multiples of 15?)