Sounds like Camping World will simply throw parts at it until something makes it work, at your expense.
Download the Norcold 12xx service manual
(100 pages, pdf) and you see the N1oP means the high temperature limit switch is open. It then lists 4 different reason for the error code, and remedies.
Has all the Norcold 12xx
recall "fixes" been performed? I think there are 3 now. This irv2.com thread
contains a wealth of information about the recalls.
2000 Winnebago Ultimate Freedom USQ40JD,
ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA." My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy