I just now read about a wood-fired hot water heater called an "Aguaheater" that is made in Mexico. Is anyone on this forum familiar with them and where they can be purchased?
There is a picture of one here: http://akzeigers.com/blog/
It's being used by a family off the grid outside of Haines, AK. The Aguaheater came with their cabin.
The photo in the link you posted looks like a Dual Megamex heater, or similar to. Read about them here.
Manufacturer's info here, if you read Spanish.
I'd appreciate hearing about the experience if you do pursue getting one.
Thank you so much for posting these links on the Dual Megamex. I was able to use Google Translator to translate the web pages from Spanish to English. I've sent them an email (using Google to translate from English to Spanish) asking them to mail me information on their heaters and let me know if they'll sell them to someone in the U.S.