I too have had a lot of trouble with the water heater. I have an XV-3 with the slide out galley. It came with the Camp Chef Triton 5 liter water heater. I took delivery in September, 2018. Almost immediately after I picked it up, the water heater sprang an internal leak because one of the internal fittings came loose. I had to unmount the water heater from the slide in order to reach and tighten the fitting. A few months later, the mounting bracket separated from the water heater frame because the welds broke. I again took it apart, drilled some holes, bolted the bracket to the water heater frame and re-mounted the water heater to the galley slide. About a year later, the heat exchanger separated from the water heater frame. It was rattling around but it did not leak. I could not repair it and I ordered another Triton 5L water heater directly from Camp Chef. Before I installed the replacement, I took the cover off and checked the internal fitting and found it was loose. I tightened the fitting, installed the water heater and it worked fine for about a year. It sprang an internal leak, and this time, there was a crack in the heat exchanger. Camp Chef was out of stock, so I went to my local Camping World and got a different brand, an Eccotemp 5L. I've had the Eccotemp for about a year, and there have been no leaks but recently, the temperature control has gone haywire and the water gets very hot and then the heater shuts off. Bottom line, three water heaters in three and a half years and possibly a fourth water heater.
Some observations:
1. The suspension on the XV-3 is very stiff. The water heater, the camp stove and the Pioneer rack have taken a beating because of the trails in the Southwest. I lower the trailer tire pressure to soften the ride when I take it off road.
2. When the water heater sprang a leak, I bypassed it by using a 1/2" diameter plastic pipe fitting between the inlet and outlet lines.
3. I seldom use the water heater for cooking or cleaning. By the time the system fires up and the warm water reaches the faucet, I waste a lot of water. For cooking and cleaning, I fill a pot with cold water and heat it on the stove. I only use the water heater for a shower.