Just use [ngValue] instead of [value]!!

export class Organisation {
  description: string;
  id: string;
  name: string;
}

orgs: []Organisations

<div class="form-group">
      <label for="organisation">Organisation
      <select id="organisation" class="form-control" (change)="selectOrg(selectedOrg)" [(ngModel)]="selectedOrg" required>
        <option *ngFor="let org of orgs" [ngValue]="org">{{org.name}}</option>
      </select>
      </label>
</div>

Just use [ngValue] instead of [value]!!

export class Organisation {
  description: string;
  id: string;
  name: string;
}
export class ScheduleComponent implements OnInit {
  selectedOrg: Organisation;
  orgs: Organisation[] = [];

  constructor(private organisationService: OrganisationService) {}

  get selectedOrgMod() {
    return this.selectedOrg;
  }

  set selectedOrgMod(value) {
    this.selectedOrg = value;
  }
}


<div class="form-group">
      <label for="organisation">Organisation
      <select id="organisation" class="form-control" [(ngModel)]="selectedOrgMod" required>
        <option *ngFor="let org of orgs" [ngValue]="org">{{org.name}}</option>
      </select>
      </label>
</div>