Jacuzzi J - 400 SERIES J - 460 - Manual (Page 53)

Page 48
J-400 Series
Consult your Jacuzzi dealer if you have any questions regarding winter
use or winterizing.
13.8 restarting Your spa in Cold weather
If you want to start up your spa after it has sat empty for a time in
freezing temperatures, be aware that the water remaining in certain
sections of the piping may still be frozen. This situation will block water
flow preventing the spa from operating properly and possibly damaging
the equipment. We recommend you consult your dealer for guidance
before attempting to restart your spa under these conditions.