How to set value of radio group programatically

Hi, is there any way, how can i set value of radio group programatically? I tried select one radio button with viewChild, and set its check attribute, the problem is, that the other button, that is checked before , stays checked. Any ideas? If i change value in ngModel variable, it wont check the correct radio button.

some advice would really help me, i cant get around it :smiley: