The answer is yes, there are a few companies that use the jet pumps as a means to conserve heat or as a heat source.
As a matter of fact, theres a company called X-spadition, that has no heating element at all. Its sole source of heating comes from the captured heat from the jet pump.
Others typically use a shroud to pull heat from the pump as a simple conservation method. HotSpring for instance, has such shrouds, though Im sure there are many more.