A system for controlling operation of a fluid pump includes a pressure sensor operably coupled to a fluid gun and a controller operably coupled to the pressure sensor. The water heater includes a water tank for storing water, at least one heating element to heat the stored water, a jacket surrounding at least a portion of the tank, and a control system for controlling the water heater. The second contact pads are soldered to the first contact pads of the package. The cam surface engages each latch key to move it from its latching position to its release position when the jar mandrel occupies a preselected position in the housing. The methods involve administering an effective amount of an agent that inhibits OX-2.