I wanted to give an update on what I found out about the E51 error code from Fisher & Paykel. This code is an error with the internal memory as one of the previous poster's said. Fisher & Paykel Rep said though it wont hurt the function of the machine it should still be replaced because it may effect the compliance information.
So, I do have an appointment tomorrow with the DME and I will take the email that Fisher & Paykel sent with me to show them what was said. I want to make sure they do replace my machine and not try to fix it or something beings the DME didn't know what the code meant.
Thank you all so much for helping me out. I really CPAPTALK very helpful.