Systems and methods for heating a fluid are disclosed. In certain embodiments, plasma is generated and passed through a conduit. A fluid to be heated can be passed over the conduit, thereby inducing a heat transfer from the plasma to the fluid. In certain embodiments, multiple plasma generators and corresponding conduits are provided and the conduits are positioned within a housing, facilitating a more effective heat transfer. In some embodiments, the plasma generator includes an outer shell, an anode, a cathode, and insulating elements, and generates plasma by passing a gas through an electric arc created between the anode and the cathode.