Is the claim that heating water to 100 degrees Celsius (the boiling point of water) at sea level causes it to boil both a sufficiency and necessity causal claim?

I am confused on this, I most definitely know that it is a necessity causal claim because water cannot boil unless it is heated to 100 degrees Celsius. But would it also be a sufficiency claim because the sun could heat it or is that already included in the phrase? I might be thinking too much into this..