Use of a liquid control valve for controlling flow of liquid in a heating and/or cooling system in a building, said valve comprising a valve housing (3; 103) with a valve chamber (5; 105) having at least two valve ports (11, 13, 15, 17; 111, 113, 115) distributed around a circumferential chamber wall (19; 119) of the valve chamber (5; 105), a valve rotor (7; 107), which is rotatably arranged inside said valve chamber (5; 105) and comprises at least one blocking portion (29, 31; 129) and a flow passage (33; 133), wherein the valve rotor (7; 107) is rotatable between a closed position, in which one of said at least two valve ports (11, 13, 15, 17; 111, 113, 115) is blocked by said blocking portion (29; 31; 129), and a first open position, in which the flow passage (33; 133) of the valve rotor (7; 107) allows fluid communication between said at least two valve ports (11, 13, 15, 17; 111, 113, 115), a groove arrangement (45; 145) formed in the valve rotor (7; 107), and an elastic sealing member (43; 143) which is configured to be received in the groove arrangement (45; 145) and move together with the valve rotor (7; 107), characterised in that said groove arrangement (45; 145) comprises at least two circumferential groove portions (45a, 45b; 145a, 145b) and at least two axial groove portions , and the sealing member (43; 143) is formed as a single piece and comprises a sealing portion (51; 147), which is configured to surround said blocking portion (29, 31; 129), and at least a first anchoring portion (47; 149, 151) projecting from one side of said sealing portion (51; 147) and being configured to fasten the sealing member (43; 143) to the valve rotor (7; 107), said first anchoring portion (47; 149, 151) comprising at least one anchor (43c; 149a, 151a, 151b) being arranged at a free end thereof for engagement with a portion of said groove arrangement (45; 145). a valve housing (3; 103) with a valve chamber (5; 105) having at least two valve ports (11, 13, 15, 17; 111, 113, 115) distributed around a circumferential chamber wall (19; 119) of the valve chamber (5; 105), a valve rotor (7; 107), which is rotatably arranged inside said valve chamber (5; 105) and comprises at least one blocking portion (29, 31; 129) and a flow passage (33; 133), wherein the valve rotor (7; 107) is rotatable between a closed position, in which one of said at least two valve ports (11, 13, 15, 17; 111, 113, 115) is blocked by said blocking portion (29; 31; 129), and a first open position, in which the flow passage (33; 133) of the valve rotor (7; 107) allows fluid communication between said at least two valve ports (11, 13, 15, 17; 111, 113, 115), a groove arrangement (45; 145) formed in the valve rotor (7; 107), and an elastic sealing member (43; 143) which is configured to be received in the groove arrangement (45; 145) and move together with the valve rotor (7; 107), characterised in that said groove arrangement (45; 145) comprises at least two circumferential groove portions (45a, 45b; 145a, 145b) and at least two axial groove portions , and the sealing member (43; 143) is formed as a single piece and comprises a sealing portion (51; 147), which is configured to surround said blocking portion (29, 31; 129), and at least a first anchoring portion (47; 149, 151) projecting from one side of said sealing portion (51; 147) and being configured to fasten the sealing member (43; 143) to the valve rotor (7; 107), said first anchoring portion (47; 149, 151) comprising at least one anchor (43c; 149a, 151a, 151b) being arranged at a free end thereof for engagement with a portion of said groove arrangement (45; 145). <EOS>