Do the lines appear when printing Black Text or only when printing colour images, etc???
Make yourself a test page by typing the following rows of letters in the colours given, i.e. Black, Red, Yellow and Blue.
Print this test page and if the unwanted lines appear in only one of the coloured lines of text then I suggest that that particular colour is running out of ink and either needs refilling or a new cartridge, which after three months is quite possible.
BLBLBLBLBLBLBLBLBLBLBLBLBLBLBLBLBLBLACK
RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRED
YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYELLOW
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBLUE
Never had an Epson but I believe that some of the models do not have print heads on the cartridges and that the print head is built in to the printer itself and can be difficult to clean.
Hope the above helps.