Our Dometic had the F5 error the first two days we setup the trailer. First day it didn't go away until the next morning and the second day it was a couple of hours. The third day when we arrived at the permanent spot it had no issues when we hooked up power. Its been three weeks and no further problems. There are several threads about this error and I was expecting it to be replaced but so far so good.
2009 F350 CC 4x4 SRW 6.4
2012 Infinity 3750FL
-Countless issues with the trailer=junk.
We had the same error code on our 2012 Voltage 3200, and found it to occur only when connected to 30 amp power, and when we used the a/c, coffee pot, toaster, micro at the same time. It seems to be a drop in voltage/amperage that causes that code.
We had ours documented for future reference, but (knock on wood), we have not had a single reoccurrence since we avoid excessive power use when hooked to 30 amp power.