I thought it would upset the apple cart a bit also Jim. That 1400 is moving some serious GPM through the system and the thermocline in the Garn seems oblivious to it as the temp readings from bottom to top showed. I was really surprised that more blending wasn"t taking place. I'll ditto the comment regarding the control setup and system being designed to work with variable water temps coming from any type of storage. That's why the method of heat transfer is just as important as the unit supplying the heat. The lower a person can use the better.