Winterize your Hot Tub Spa

Winterize your Hot Tub Spa – Thermo-Spas

Hot Tub Winterizing/Closing

If you do not plan to use your spa during freezing weather, you will have to winterize it. Failure to winterize your spa will cause irreversible damage (in freezing temperatures) to the pump and plumbing lines.

Winterization of your hot tub is easy. Follow the steps in this checklist each time you drain the water from your spa in freezing temperatures to prevent serious damage from occurring to your hot tub:

Hot Tub Winterizing/Closing Steps
Step 1: Close all therapy control valves and open all jets.
Step 2: Turn the spa circuit breaker off.
Step 3: Drain your spa. We recommend using a submersible pump. If you don’t have a submersible pump, you can attach a garden hose to the hose spigot, located on the primary water pump within the spa interior. Be sure to run the drain line to an area that can handle the drainage. (see Figure 1)
Step 4: Remove the cabinet panel in front of the spa’s equipment compartment.
Step 5: Open the hose spigot located near the primary pump to drain any remaining water and leave open afterwards.
Step 6: Locate the heater and open the heater unions at both ends by turning counter-clockwise. (see Figure 2)
Step 7: Clear water from the water pump(s) suction and return lines using a canister-type wet vacuum. You MUST use a canister type wet vacuum in order to ensure that the lines are cleared of all remaining water.
Step 8: Remove the drain plug(s) from all water pump(s). (see Figure 1)
Step 9: Replace the pump plug(s) after all the water has drained from them.
Step 10: Reconnect the heater unions on the heater at both ends by turning clockwise until they are tight. Make sure O-ring gaskets are sealed properly so as not to pinch O-rings. Do not over-tighten.
Step 11: Put the cabinet panel in front of the equipment compartment back on.
Step 12: Turn the spa circuit breaker on.
Step 13: Turn the blower on to expel water from the plumbing and air channels.
Step 14: Turn the spa circuit breaker off.
Step 15: Remove the insulated cover from the spa.
Step 16: Use a wet vacuum at EACH fitting to assist in removing any existing water in fittings, water lines and spa shell.
Step 17: Sponge out remaining water from spa shell.
Step 18: Clean the shell and remove any debris.
Step 19: Clean the filter. Store the filter basket and filter element indoors.
Step 20: Install the insulated spa cover and check to ensure that rain water and/or snow is not entering the spa through the cover.


Water Pump
Figure 1 – Water Pump
Pac & Heater
Figure 2 – Pac & Heater


Customer ResponsibilitiesAny spa/hot tub is subject to freezing in cold weather. You must follow these procedures during a power failure or if the hot tub spa is not operating properly in order to prevent your hot tub spa from freezing.

Preventative Maintenance During the cold weather season, you should inspect your outdoor hot tub spa every day to insure it is running properly. If you detect a problem and the temperature is dropping, contact the service department immediately during regular working hours. It is the customer’s responsibility to follow the procedures listed above in order to prevent a freeze up.

Thermo Spas can winterize your spa for you!

Call 1-800-876-0158 for your appointment.