A frictionless, pressure balanced proportioning valve assembly for low power electric operated thermostatic mixing valves, comprising: a. a housing having a first water inlet, a second water inlet, an intermediate mixed water outlet, a spool bore formed in said housing, said spool bore being in flow communication with the first and second water inlets; b. a spool, guided in said spool bore, said spool having a first and a second widened end portions (28, 30), and a central widened two sided disk portion; c. a temperature sensor exposed to the mixed water outlet pathway, generating an electronic signal amplifiable by an electronic circuit, and d. an attached drive means, provided for axially displacing said spool, wherein said axial displacement of said spool, adjusts the proportions flow from said first and second water inlets to said mixed water outlet, characterized in that said spool bore has a central widened portion being in flow communication with said intermediate mixed water outlet; said two sided disk portion is axially shorter than said widened portion of said spool bore, wherein said spool is loosely axially movable within said spool bore with said two sided disk portion traveling in said widened portion of said spool bore between two opposing seats (32, 33) and separating said spool bore into a first tubular water inlet chamber and a second tubular water inlet chamber, a first and a second elastic diaphragm seal (40, 42) are respectively provided at each end of said spool and said housing, said elastic diaphragm seals (40, 42) being configured, by effective area equalization, for pressure balancing of said first tubular water inlet chamber between said first elastic diaphragm seal and said two sided disk portion, and pressure balancing of said second tubular water inlet chamber between said second elastic diaphragm seal and said two sided disk portion; and the attached drive means are adapted to be energized by said electronic circuit driving a low power electric motor. a. a housing having a first water inlet, a second water inlet, an intermediate mixed water outlet, a spool bore formed in said housing, said spool bore being in flow communication with the first and second water inlets; b. a spool, guided in said spool bore, said spool having a first and a second widened end portions (28, 30), and a central widened two sided disk portion; c. a temperature sensor exposed to the mixed water outlet pathway, generating an electronic signal amplifiable by an electronic circuit, and d. an attached drive means, provided for axially displacing said spool, wherein said axial displacement of said spool, adjusts the proportions flow from said first and second water inlets to said mixed water outlet, said spool bore has a central widened portion being in flow communication with said intermediate mixed water outlet; said two sided disk portion is axially shorter than said widened portion of said spool bore, wherein said spool is loosely axially movable within said spool bore with said two sided disk portion traveling in said widened portion of said spool bore between two opposing seats (32, 33) and separating said spool bore into a first tubular water inlet chamber and a second tubular water inlet chamber, a first and a second elastic diaphragm seal (40, 42) are respectively provided at each end of said spool and said housing, said elastic diaphragm seals (40, 42) being configured, by effective area equalization, for pressure balancing of said first tubular water inlet chamber between said first elastic diaphragm seal and said two sided disk portion, and pressure balancing of said second tubular water inlet chamber between said second elastic diaphragm seal and said two sided disk portion; and the attached drive means are adapted to be energized by said electronic circuit driving a low power electric motor.