If you block ports on your router, you need to verify that you have opened the ports needed for the Purezone to operate properly

Purezone needs the following ports to be open. Purezone always initiates communication to its servers so while the ports need to be open going out, no port forwarding is needed.

• HTTP Port 80 to "s3-us-west-2.amazonaws.com" for logging and to "httpbin.org" if support needs to diagnose Wi-Fi issues
• TCP Ports 23639 and 45476 to "pod-server.prod.waterguru-api.com" for firmware download and regular secure (CCM with per-unit private key) communication 

Is pod-server.prod.waterguru-api.com the only destination that the Purezone needs to communicate with?

Purezone uses the following TCP connections:

• pod-server.prod.waterguru-api.com (depending on env it also can be qa, dev) on
  port 45476 for communication with the pod server
• port 23639 for downloading firmware
• s3-us-west-2.amazonaws.com
• port 80 for uploading text logs
• httpbin.org
• port 80 only as a reaction on CLI cmd "wifi test"