Everyone should use what makes sense to them. I in no way am trying to talk anyone into using any specific product. Just putting what info I know out there to try and contribute to the overall community understanding so that people can make intelligent decisions. And to try and make some sense of what has happened on the Aquahot failures noted todate.
I agree with Richard's comment that it takes more than just proplene glycol and water to make an acceptable coolant. That is why it is important to not blame only the PG specifically for the problem.
But, to make an acceptable coolant I feel it needs the corrosion inhibitors so that is why the LoTox is mentioned. LoTox is probably overkill for this application but it is available as an option if you understand what is going on and how the coolant interacts with the system.
The best bet I have is that Century made a bad batch of coolant by either using contaminated or inferior material and or tap water with a lot of mineral content or mixing it with some other product in their system they use for bottling....???? All just guesses or possible examples.
Nice thing about buying pure food grade PG or LoTox and mixing it yourself with distilled water is that you control the ingredients and the concentrations yourself eliminating their quality control to some extent. It is also less expensive to do this. Aquahot would never officially condone it because of liability issues.
Historically there are numerous examples of coolant vendors making major mistakes with coolants. Straight coolant has been delivered under the guise of 50/50 premix. Coolant has been delivered without the correct corrosion inhibitors and/or the completely wrong corrosion inhibitor or the wrong concentration of corrosion inhibitors. The wrong products were put into the wrong containers and labeled incorrectly because of mistakes at the bottling facilities. Chinese products have killed people because the Chinese put ethylene glycol in toothpaste and mouth wash instead of propylene glycol.....read the labels, PG is a common ingredient. PG is primarily used in the food industry to retain moisture and add viscosity to many products and packaged baked goods. In these applications PG is totally GRAS compliant where small amounts of ethylene glycol are extremely toxic.
It is very easy to envision Camco or Century making a bad batch of coolant based on the precedents I have personally witnessed or read about.
Finally, the subject of coolants for any given application is very complicated.
There is no single correct answer for everything or everybody.
Every specific application requires intense scrutiny for the final answer and stating it is very risky due to unknown variables of each operator. Even in the case of a coach it would matter as to what year, model of AquaHot and use schedule that operator requires. If the domestic water loop is outside of the coolant container the Ethylene Glycol would be perfectly acceptable. In the case of the older, presurized systems the concentration would be much less critical than without pressure. So....to each his own.
I've about run out of patience on the AquaHot for the moment
