Now the difficult question. Would I install this system again. The short answer is no. I truly hate to say that because the cool factor is way up there. If I built my own RV I don't think I could justify the cost. I also worry a lot about the coolant lines chafing somewhere I can't see them. I had a system down in my chinook for shower water. I put a temperature sensor directly onto the hot water tank with a remote thermometer on the wall. When the temp was right I turned off the heater and jumped into the shower with only the hot valve open. No mixing and wasting water getting the right temp. Yes I'm cheap, and yes my propane lasted a long time.
guy online who will do a rebuild for around a hundred bucks plus parts. Well, he quickly called me and stated that mine was heavily used and too old to rebuild. For only $650 I could get a new one. Yes I bought it, both the story and the new unit. I've found that most times it pays to start over with an appliance especially one that rides outside of the vehicle. So I put the new one on and fired it up. It made a few whirring noises and never made another sound. Grrr, I decided to walk away and see if it would do better later. Sometimes these high tech parts need to have a time out. No such luck.
I happened to stop by EarthRoamer soon after the install so I asked them about it. They tested it for me and found the problem with the fuel solenoid. Fuel solenoid disconnected or not working. Hmmm. I called my guy back and he said he has never seen one not work. I could simply put 12v to one wire and ground the other to test it. If it clicked it was working. So under I go again. When I unplugged the control plug to the unit the green wire fell out of the plug. I bet you can guess where the green wire goes. Yep, directly to the fuel solenoid. Yay!! It's such a good feeling when you troubleshoot and find the problem. So I now have a very nice working hot water system. As before, I almost never use the hydronic fuel fired heater. I guess I move enough to have the water heated every couple of days. It is also very nice to fire this thing up for hot water when parked for a while. I also recently used the heater to preheat the truck before starting. I didn't really need to since it was only around 30 degrees, but it was sure nice to have an already warm truck to start.
Ok, again, would I buy the system again. At this time I think I'd go with serious solar and batteries and heat water electrically instead of dealing with these complicated water systems.