def set_relay_off(self):
        """Turn the relay off."""
        if self.get_relay_state():
            try:
                request = requests.get(
                    '{}/relay'.format(self.resource), params={'state': '0'},
                    timeout=self.timeout)
                if request.status_code == 200:
                    self.data['relay'] = False
            except requests.exceptions.ConnectionError:
                raise exceptions.MyStromConnectionError()