Does anyone have any actual operating experience with the heat recovery pump used in the Vita Duet and other low-end spas (in place of an actual heating element)? I have never run into this before.
I am helping a friend restore an eight year old Duet and very curious as to what to expect from this system in terms of rise (degrees per hour) once we get it running again. And what happens if/when the tub reaches 104. Does the pump refuse to operate altogether until the temperature drops again?
Very little on the web about this pump and its workings.