I got a quick reply from Epson support:
"I would suggest you power off the product and remove the power and data cable for at least a minute, lift the lid to check for any foreign objects, remove any paper or other items that should not be there. If the error remains it indicates a hardware fault within the product and it will require a repair."
So, pretty much what I expected from them. I had already tried what they suggested, but was hoping there would be a solution to this problem before I decide to bin it