To connect with your FTP server it is recommended to use Passive mode for all connection. And to do that you have to enable passive mode on your PureFTP package in your server.
Simply go to your PureFTP config file and remove enable passivePortRange option in config file. Open the config file with your suitable editor
sudo vi /etc/pure-ftpd.confRemove the comment (#) from the beginning of the line which contains the PassivePortRange option.
Change that line to the following:
PassivePortRange 49152 65534
Save the changes to the configuration file.
Now restart pureFtp and you can connect to your FTP server with Passive mode.
To enable passive mode on your centOS powered cPanel server please read this post