Sam Kosofsky asks:
Rebbe,
It's about 110 miles from Teverya to Yerushalayim. You couldn't get the korban pesach to Yerushalayim from chatzot until nightfall if you had boiled it in chamei Teverya. Besides for that I don't think you're allowed to cook it outside of Yerushalayim anyway. What's the gemara's hava amina? Why bother ruling it out when it's not possible logistically anyway?
B'kavod,
Sam Kosofsky
The Kollel replies:
Dear Sam,
Chamei Teverya is "the" example of "hot water not heated by fire"- but it's only an example. The Gemara means that if there is such a similar hot springs in the Yerushalayim area then...
All the best,
Reuven Weiner