The following instructions are general guidelines to assist you in properly winterizing a spa. It is recommended that this service be provided by an authorized service technician if possible. The steps may differ slightly depending on the particular spa model.
Turn off the power to the spa at the breaker. After draining the spa, disconnect the unions from all pumps and use a high-volume shop vacuum (3 HP or higher), to blow air through both the discharge and suction plumbing lines.
With the shop vacuum on, move the topside diverter valve from one position to the other and open and close each jet face until no more water comes out of the jets.
Connect the shop vacuum to each of the plumbing lines and suction fittings (essential for models with 2-speed pumps and 2″ check valves) and blow/suck out the lines until there is no more evidence of water, gurgling sounds, or mist coming from the suction fittings in the footwell of the spa.
Vacuum and residual water from the spa and remove all pump drain plugs and leave all pump unions disconnected in case rainwater makes its way back into the suction fittings or drains.
Remove the filter and plug the smaller suction port into the filter bucket. Attach the vacuum’s blower to the main filter line to clear any residual water from the circulation pump plumbing.
Open and close the waterfall valve (if applicable) until the water is cleared from the waterfall plumbing.
Remove the plumbing connections from the heater and blow out the heater line. Leave these disconnected.
Remove the plug from the smaller port in the filter bucket and blow any residual water out of this line. Check all 3/4″ lines for any residual water and disconnect the unions or remove clamps and hoses and remove the drain plug (if applicable) from the circulation pump. Blow these lines and the circulation pump out. Leave the unions disconnected. Wipeout any residual water and then cover the spa and hardcover with a tarp to prevent water intrusion. The spa should be tarped in such a manner that seals and prevents rain or snow from entering through the cover and the tarp should be attached securely enough to handle adverse weather conditions.