Originally Posted by Dr4Film
I am not an expert like Roger Berke however, for the life of me I am having difficulty understanding how the domestic hot water will get HOT if it is on the outside of the boiler and not inside.
To my knowledge, the boiler coolant mixture is heated by the Webasto burner and the electric heating element which then transfers the heat to the domestic hot water loop which wanders inside the boiler coolant mixture.
Dr4Film ----- Richard
In around '04-'05 AquaHot changed the design and put the hot water loop inside the tank in direct contact with the coolant mixture. Up until that design change, the hot water loop wrapped around the outside of the tank. The copper water loop is in direct contact with the steel boiler vessel and the heat transfer is plenty good. This was the design up through the 100-02s which is the version I have. When the loop went inside the boiler AquaHot started requiring non toxic fluid. Before that time standard green ethylene glycol was used in a 50/50 solution.