Green-dot: okay, thanks. Not sure what the point of a water-detection system that only triggers at such a high volume is, though.
Airfoilmod: your physics is wrong. You seem to be muddling gas and liquid behaviour. Water freezes at 0°C. The pop-bottle phenomenon which you cite is to do with super-cooling. The release of pressure causes the appearance of finely dispersed CO2 bubbles which act as nucleation sites for crystallisation.