Abstract: A mobile surface heater is disclosed having a heat generation loop and a heat dissipation loop. The heat generation loop can include a heat generating device, a storage tank, and a first pump for circulating a fluid. The heat dissipation loop can be placed in fluid communication with the heat generation loop and includes a ground heating system having at least one heat transfer conduit extending between a supply manifold and a return manifold. A control valve can also be provided to deliver a mixed fluid flow stream to the ground heating system by selectively mixing fluid from the heat generation loop with fluid returning from the ground heating system return manifold. In one embodiment, an electronic controller is provided that operates the mixing valve to maintain a temperature setpoint of the mixed fluid flow stream and to maintain a minimum entering fluid temperature setpoint of the atmospheric water heater.