Hi all,
We have an ESPAR D5WSC Hydronic system on-board which runs 3 heat exchanger stations and can heat the hot water tank. The coolant in the heater system is Prestone (green) while the boat's motor is using Delo ELC (red or pink).
I have not been using the hot water branch of the Espar because I am concerned about the two coolants cross-mixing in the few feet of hosing to and from the water heater, not to mention the water jacket inside the heater itself.
First off, is this a real concern? It is my understanding that one should not mix colors of coolant as they can sludge.
Second, if it is a concern, I am thinking of flushing the Espar system clean and switching to Delo ELC so the coolant types match. I don't think I can fully drain the system due to all of the dips and turns of the hoses throughout the boat. So, I am thinking of draining the pressure tank and overflow tank and any hose connections I can reach that are low in position. Then fill the system with straight water and run for 15 minutes. Drain out the water as before and re-fill with water and run for another 15 minutes. Then fill the system with the new coolant and be done.
Also, I understand that the heater systems will carry more heat if you use less coolant/more water, and one doesn't really need to run 50/50 coolant if they aren't in super cold environments. However, I am again concerned with the coolants of the engine and Espar system mixing at the water heater and effecting one another. Therefore, should I just run the 50/50 mix in the Espar?
Dale and Nikki
1998 C36 mkII SR hailing from Poulsbo, WA
1989 C25 TR/WK