Newell Gurus

Full Version: Aquahot modification
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Our aquahot was not working on diesel, the control board had filled with water and been that way for years so it was not possible to repair. I decided to purchase Chinese diesel water heater and experiment with it when I bought this it was $286 so they have gone up.

https://www.amazon.com/ZAWAYINE-Parking-...172&sr=8-5

I first hooked the water heater in a loop on the fresh water side, the little pump would circulate water through the aquahot and to the hot water manifold on the fresh water but it would heat up very quickly and the high temp limit of the diesel heater would shut it down at 192 F. Next I circulated the coolant from the engine feed to the aquahot and it worked but would take 30-40 minutes to heat the aquahot so after searching through the threads I found Richards post about his solution to hot water and used his idea of a flat plate heat exchanger in series with the diesel heater plumbed into the engine feed. The flat plate heat exchanger is first in line then the aquahot is second and the results are amazing. The Chinese diesel water heater has a remote control so you can turn it on via wifi and it will get to 120 F in 5 minutes and it will supply hot water to the hot water manifold continuously as long as the heater is on. It also will heat the engine as its tied into that circuit. I don't think it big enough to heat the coach and I never planned on that. I used the exhaust of the aquahot for the exhaust of the Chinese diesel heater.
Your Aqua Hot heater coolant overflow bottle is empty. Remove the radiator cap and fill lipping full with distilled water and engine antifreeze, 50/50 mix. When coolant tank is completely full and radiator cap back on, bring the coolant up to temp with diesel burner. When burner cycles off, use same solution to fill overflow tank to the hot line.

If you need gallons of antifreeze solution to fill the tank, no wonder you have hot water problems.

Congratulations on your mod. But my heater provides unlimited hot showers just fine in my 2001 motorhome.
Thanks Rudy, I made the mod to get away from the electric element. The aqua hot tank is full I drained the coolant recovery tank when I was plumbing in the system. Good eye Rudy!
Okay Bud, you be that way. Now come put one on my coach, lol.