The invention relates to a gas valve unit, comprising a valve body surrounding an inner chamber in a sealing manner; an inlet part; at least one gas outlet in connection with the inner chamber to conduct gas via an outlet channel; a stationary disc member dividing the inner chamber; a rotating control disc member which is superimposed on a corresponding rear wall of the stationary disc member from an inner wall and mounted on a lower part which extends into the inner chamber of a control rod extending out from the body; also an elongated cavity formed in the inner wall of the control disc member and aligned to direct the gas flow to the through hole in an operational position.