I have a question - and if there is somebody who can definitively answer it we could all learn more about this topic. The question is based on working on Freeflow spas, specifically the one available directly (not through dealers) which have "friction heat."
My question: what exactly is the difference between the pumps used in these two types of spas? I know that on the heat recovery spa there is a little control box on the MOTOR, and I would guess that it contains a temp high-limit system to protect the motor itself. This makes sense because these types of systems can run the pump for a couple of days before the tub is at temp, and they close up the motor compartments pretty tightly. But I'm not talking about the
motor - I am asking if there is anything different or special about the
PUMP.
All of our pumps impart some heat into the water, and you can heat just about any (well insulated) spa by just running all the pumps with the lid tightly closed.
I have looked the pumps over very thoroughly, and I can't see a thing different about them - to the naked eye, they look exactly like the pumps installed in the other models which are equipped with a heating element.
What I'm getting at is this: if there is no difference in the pumps, then the answer to the OP question is this: Buy a Freeflow, because you will be getting heat from the element AND the pump. If there is a difference, I would love to know what it is - and I would also love to know why they don't put these pumps in all of the spas out there, to provide a small boost to the heating system?