HTTP 418: I'm a teapot

This means the requested machine shouldn't be brewing coffee.

What are you brewing?

• If it's tea, you don't need to do anything else but wait.
• If it's coffee, try double checking your URL for mistakes.

Also, some machines don't support remote tea-brewing. In that case, you can still tip it's pot over when ready (it should give out an audible signal), and pour the tea out.

If in doubt, consult with a barrista or any other sensible, suitable source for further actions.