If I had just recently purchased it I might have tried dealing with my dealer but because the warrantee period had already passed I spoke with Neptune directly.
https://www.neptunesystems.com/support/contact-support/ They tried to trouble shoot with me a bit but it was pretty apparent that there was nothing that I could do. So they gave me a support ticket number and some shipping directions to send it back. I had to pay for shipping down and the repair but they covered the cost of the return.