Are you clicking the correct ring?
Maybe you are using healing halo instead?
Fire rain rains down fire on animated, healing halo is the only one I can think of that put like a gold/orange ring around yourself.
Maybe I am wrong though, I have only used fire rain once. lol
It's not really my cup of tea.
You have to use it near the animated for it to rain fire.
This ring works even without a target, in the above case you have used it like that, I assume.