never
When you boil water, a lot of air-bubbles appears on the surface. it is the water turning into steam.
Ice melting and evaporating.
Sublimation
evaporates.
The boiling water will evaporate (turn to vapor). The ice will melt (turn to liquid) and then begin to evaporate (turn to vapor). The tap water will begin to evaporate (turn to vapor).
Yes, for example if an ice cube (solid) melts than that water (liquid) evaporates and turns in to water vapor than the solid did turn into a gas from ice cube to water vapor.
Without having a stop in the run you'll have to turn off the system, unless...If it is the hot water side you can turn it off at the water heater.
Condensation
When water vapor is cooled it turns into liquid.
It has to cool down and condense.
Evaporation of sea water does absolutely nothing for a hurricane except provide water vapor. When the water vapor turns back to water in the form of rain it gives off heat. Hurricanes are massive heat engines. As long as they have water vapor to turn into heat they can continue blowing along. Without water vapor, the hurricane has no source of heat.
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