The present disclosure relates to a thermostat that can be attached to a valve for a radiator, wherein the thermostat is attached to the valve for influencing a valve pin of the valve. The thermostat has a base portion (9), which is adapted to be fixed in relation to the valve of the radiator, and a sensing element (33) which depending on room temperature influences a piston (37, 38, 39, 41) an end (41) of the which controls the valve pin. A removable pin is initially inserted in the thermostat and prohibits the piston from influencing the valve pin until the removable pin is removed. This allows the valve to be kept in a reference setting when balancing a heating system during installation. When the balancing is completed, the pin may readily be removed by and end user.