This is what can happen if you dot have a frost stat fitted to a fountain

Although this fountain was switched on just to get the picture it shows why you should turn fountains off in cold weather or fit a frost stat. the nozzle had frozen almost solid and if this fountain was left to run it would have soon emptied the pool (although it has a float switch the float switch is held in the horizontal position by the ice)

This is why we recommend a frost stat. the normal height of this jet is about 40cm