Is there some way to use a 3 phase 240v heater hooked up single phase 240v.

Sorry, but no. Don't even try.

Some heaters can be converted from 3-phase to single. Depends on the heater itself.
All heating elements are single phase, it's just how the multiple elements are wired inside the unit to balance the load that makes it 3-phase.
If the unit is convertible then any fan motor would also be single phase.

Good info, stanforty. I guess I have only dealt with non convertible units. Caught me talking out of my zone of knowledge. Good catch.