A fluid preheater (10) includes a body (12) having an interior wall (28) defining a chamber (42) and having an inlet (50) and an outlet (52). One or more heaters (18) are disposed in the wall (28), but not exposed to the chamber (42). The chamber (42) has one or more baffles that cause turbulence in the flow of fluid through the chamber (42) from the inlet (50) to the outlet (52) in order to increase the exposure of the fluid to heat from the heaters (18, 64).