When ours was new, first long trip we had same or similar issue with code E6. AirExel would not put me in touch with a tech, so I called a mobile tech. Thru troubleshooting etc…There are two flat fuses in that unit, one was blown & when we replaced it the unit worked, until the next day. Had to replace the fuse at least after every move for hot water. After a couple of weeks it finally went out completely. When we got home, we took it into CW, they replaced the pressure switch under warranty & it’s worked fine since. The fuses are hard to get to, as is the water heater. In 2018 there was no COVID but CW, even with an appointment, had to keep the unit for many days (month or months) to get parts & make repairs.
Ron & Renee’
2019 F350 Platinum SRW 4X4 6 3/4’ Bed