Inline heater in soaker tub without jets
I'm about to purchase a MTI 60" soaker tub without jets and it has an inline heater. If the water is not circulating through jets, how does the inline heater keep the water warm? They also sell a "Radiance" system that radiates heat through the walls of the tub, but that's more expensive.
If anyone has an inline heater in a soaker tub without jets, can you tell me how it works?