Abstract: An improved freezeproof or freeze resistant valve assembly is provided for use in an outdoor drinking fountain or the like. The fountain includes a main on-off valve for coupling an underground water supply conduit via a standpipe to a fountain head to dispense water. The freezeproof assembly comprises a sump chamber installed below the frost line and having a piston mounted therein for reciprocal movement between advanced and retracted positions. When the main valve is turned off, the piston retracts by gravity within the sump chamber and residual water remaining within the standpipe drains to the sump chamber at low pressure through a normally open control valve mounted on the piston. When the main valve is turned on, the control valve is closed by water pressure and the piston is advanced within the sump chamber to expel the water previously collected therein through a discharge conduit coupled to a main fountain drain.