Winterizing a hot tub allows you to close the unit if you have no intention of using it during colder months. Sundance hot tubs have an internal mechanism that maintains a certain water temperature level to ensure that the spa does not incur damage from freezing temperatures. However, long periods of no use or power outages may result in your having to winterize it.
Turn off the power to the hot tub. You can do this at the breaker or ground fault circuit interrupter (GFCI) depending on your hot tub set up.
Remove the tub's external center panel just beneath the control panel.
Locate the drain port. Connect a garden hose to this port and open it, which will begin the tub draining process.
Close the drain port when the tub is half empty. Turn on the power to the hot tub. Turn on the blower to force water out of the spa's internal plumbing.
Turn the power back off and continue draining the tub. Use a shop vacuum to remove any remaining water in the foot well and other tub areas.
Remove the external panels covering the spa's internal equipment. Open the drain plugs by each pump to remove water from these pipes and the pump or heater.
Release the hose clamp and remove the hose near the heater. Hold the hose at a downward angle to release water and then replace the hose and hose clamp.
Replace all the external hot tub panels and place a cover over the hot tub. Make sure the cover is sealed tightly to prevent water from entering the tub.