Port forwarding help needed.

I figured out that i need to forward the ip address of the heater meter. What do i use for service name? Currently i have it set to ftp. Also what external port number? It is set at ports 20,21 now. How then do i connect to it from outside my network?

Ok, i figured it out. Now how do i make heatermeters ip permanent?

I'm going to assume that you've set your HM up as a DHCP/dynamic address. In your DHCP server (probably your firewall/router,) you need to create a permanent lease for your HM's MAC address. That'll give it the same address every time it requests a lease or a renewal. This address and the port forwarding address need to match.