AMZCHEF 65,000BTU RV Tankless Water Heater - CSA Certified 3.9 GPM On-Demand Hot Water System with 15x15" Black Door & Remote Controller, 12V Power for RVs, Campers & Tiny Homes - Endless Hot Water up to 9800FT Elevation - Perfect for Showers, Kitchen & Laundry in Mobile Living

I am very happy with this hot water heater. It replaced a 20 year old Precision Temp RV500 unit, which currently costs $1200. This heater performs nearly as good as the RV500, (which costs 3 times as much), plus it has the wall controller which the RV-500 did not have. Easy to install. Good instructions. Not sure if it will last 20 years. The only downside I have noticed is that it takes about 5 seconds of water running before the burner ignites. The RV500 would fire the burner in about 1 second. This is mostly noticeable when turning water on and off repeatedly like when washing dishes. It does waste a bit more water waiting for the heated water to arrive. So far that's the only downside. It would be great if the manufacturer could make the burner ignite as soon as water starts flowing, instead of 5 second delay. But price is very good, and overall it's a minor issue. After about 15 seconds the water reaches set temperature, depending on water temperature incoming. I have mine set at 115 F and it's perfect for endless showers.The installation manual shows two types of PEX fittings with rubber washers for hot and cold water connections. Two rubber washers are provided in the hardware kit, but I did not use them. I believe this way is recommended so you don't put a lot of torque on the copper connections, possibly twisting them off and ruining the heater. I used 1/2" FNPT Sharkbite MAX fittings with three wraps of Blue Monster teflon tape being careful not to put too much torque on the hot / cold fittings when tightening. The Sharkbite MAX fittings are great because they allow twisting movement of the pipe and can be easily released if the heater needs to be removed. Also avoids having to solder regular copper connections in a confined space. I used copper pipe with the Sharkbite fittings since I had already plumbed my system with copper 20 years ago and still had some pipe and fittings on hand.