Abstract: A pressure maintenance assembly for a domestic water well system. The assembly includes a pressure maintenance valve having an inlet side and an outlet side, a pressure tank in fluidic communication with the outlet side, and a calibrated bypass. When the valve is closed, the calibrated bypass provides fluidic communication between the inlet side and the outlet side. The size of the calibrated bypass and the pressure tank are adapted and constructed to permit a flow rate between the inlet side and the outlet side that will fill the pressure tank in a time interval at least as great as but less than twice the time required to pump a volume of water that will dissipate heat generated by the pump when it is turned on.