Winterizing a hot tub is important if you plan to shut it down during freezing weather. A hot tub is filled with plumbing lines, pumps, manifolds, jets, valves, unions, heaters, and fittings that can hold water even after the spa is drained. If that water freezes, it can expand and crack expensive parts.
In many cases, keeping the hot tub running through winter is easier and safer than shutting it down. However, if you will be away for an extended period, the spa will not be monitored, or you do not plan to use it for the season, winterizing may be the better option. The goal is simple: remove as much water as possible from the shell, plumbing, pumps, heater, filter area, and jet lines so freezing temperatures cannot damage the system.
1. Decide Whether You Should Winterize Or Keep It Running
Before winterizing, decide whether shutting the spa down is really the best option. Many hot tubs are designed to run year-round, and keeping the water heated and circulating can help protect the plumbing from freezing.
- Keeping the spa running may be easier if you use it during winter.
- Winterizing makes sense if the spa will be unused for a long time.
- Power outages can create freeze risk if the spa is not monitored.
- Poor winterization can cause expensive damage.
Solution: If you can maintain heat, water level, and power all winter, keeping the spa running may be best. If you are shutting it down, winterize carefully and completely.
2. Gather Supplies Before You Start
Winterizing is easier when everything is ready before the water is drained. Once the spa is empty, you do not want to leave plumbing partially filled while searching for supplies.
- Submersible pump or drain hose for removing water.
- Wet/dry vacuum for pulling or blowing water from lines.
- Towels or sponges for remaining water in seats and footwell.
- Spa plumbing cleaner if buildup is suspected.
- Filter cleaner and a safe storage area for dry filters.
Solution: Prepare your winterizing supplies before turning off power or draining the spa. A wet/dry vacuum is especially helpful for clearing plumbing lines.
3. Use A Plumbing Cleaner Before Draining If Needed
If the spa has had cloudy water, foam, odor, sanitizer loss, or possible biofilm, use a plumbing cleaner before draining. This helps loosen buildup inside lines so it can be flushed out with the old water.
- Biofilm can hide inside plumbing.
- Plumbing cleaner works before draining.
- Jets and pumps help circulate the cleaner.
- Cleaning first helps the spa restart cleaner later.
Solution: Add plumbing cleaner according to the product directions, run the system as instructed, then continue with the winterizing process.
4. Turn Off Power At The Breaker
Power should be turned off before draining. Pumps and heaters should never run without enough water. Running equipment dry can damage pump seals, heater elements, wet ends, and other components.
- Dry pumps can damage seals.
- Heaters can dry fire without water flow.
- Electrical safety matters during service.
- Breakers should stay off while winterized.
Solution: Turn off the spa at the breaker before draining. Confirm the control panel is off and leave power off until the spa is refilled and ready to restart.
5. Drain The Spa Completely
Use the spa’s drain valve, a drain hose, or a submersible pump to remove the water. A submersible pump is usually faster and can help remove most of the water from the shell.
- Drain as much water as possible.
- Direct water to a safe drainage area.
- Remove water from seats and footwell.
- Do not leave standing water in the shell.
Solution: Drain the spa fully, then use towels, sponges, or a wet/dry vacuum to remove remaining water from low spots.
6. Remove And Clean The Filter
The filter should not sit wet inside a winterized spa. A dirty or damp filter can hold residue, oils, and contaminants. It may also develop odors or deterioration during storage.
- Remove the filter cartridge.
- Rinse loose debris from the pleats.
- Deep clean with spa filter cleaner.
- Let the filter dry completely before storage.
Solution: Clean, dry, and store the filter indoors. Replace it before spring startup if it is cracked, greasy, torn, flattened, or no longer rinses clean.
7. Clear Water From Jet Lines
Jet lines can hold water after the shell is drained. If that water freezes, it can crack fittings, hoses, manifolds, or jet bodies. Clearing these lines is one of the most important winterizing steps.
- Water can remain behind jet fittings.
- Manifolds and small lines can trap water.
- Frozen water can split plumbing.
- A wet/dry vacuum can help clear lines.
Solution: Use a wet/dry vacuum to blow or suction water from each jet line. Work through the jets methodically so hidden lines are not missed.
8. Clear The Filter Area And Suction Lines
The filter compartment, skimmer area, suction fittings, and drain lines can also trap water. These areas are easy to overlook because they may still hold water after the main shell is drained.
- Filter housings can hold water.
- Suction lines can trap water below the shell.
- Drain fittings may still contain water.
- Low plumbing areas are freeze-risk points.
Solution: Use the wet/dry vacuum on the filter area, suction fittings, and drain openings to remove as much water as possible.
9. Drain Pumps, Heater, And Equipment Unions
Pumps, wet ends, heater tubes, unions, and equipment plumbing can hold water even after the spa looks empty. These parts are expensive and should be protected from freezing.
- Pump wet ends can hold water.
- Heater tubes can trap water.
- Unions may need to be loosened to drain trapped water.
- Drain plugs may be located on pump wet ends.
Solution: Open the equipment bay and remove pump drain plugs if present. Loosen pump and heater unions carefully to let trapped water drain. Keep gaskets and O-rings safe for reassembly.
10. Do Not Forget Air Blower Lines If Your Spa Has A Blower
Some hot tubs have an air blower system. Air lines can collect moisture, and water trapped in blower plumbing can freeze or cause problems later.
- Blower systems may have separate air channels.
- Moisture can collect in low spots.
- Air injectors may need attention.
- Not every spa has a blower.
Solution: If your spa has a blower, follow the manufacturer’s winterizing instructions for clearing blower lines. If unsure, have a spa technician handle this step.
11. Clean And Dry The Shell
Before closing the spa for the season, clean the shell, seats, waterline, and footwell. Any residue left behind can dry onto the surface and make spring startup harder.
- Wipe the waterline.
- Clean seats and footwell.
- Use spa-safe cleaners.
- Dry remaining moisture.
Solution: Clean the shell with a spa-safe surface cleaner and dry it thoroughly. Avoid household soaps that can cause foam when the spa is refilled.
12. Secure The Cover And Protect The Spa
Once the spa is winterized, the cover becomes your main protection against weather, debris, animals, and accidental water entry. A damaged or poorly sealed cover can allow rain, snow, and debris into the empty shell.
- Latch the cover securely.
- Replace broken straps or clips.
- Remove heavy snow from the cover.
- Consider a protective cover cap in harsh weather.
Solution: Close and latch the cover after winterizing. Check it periodically through the season, especially after storms, wind, or heavy snow.
Quick Hot Tub Winterizing Checklist
- Decide whether winterizing is better than keeping the spa running.
- Gather a submersible pump, wet/dry vacuum, towels, and filter cleaner.
- Use plumbing cleaner first if buildup or biofilm is suspected.
- Turn off power at the breaker.
- Drain the spa completely.
- Remove, clean, dry, and store the filter indoors.
- Vacuum or blow water from jet lines.
- Clear water from the filter area, suctions, and drains.
- Drain pumps, wet ends, heater tubes, and unions.
- Clear blower lines if your spa has a blower.
- Clean and dry the shell.
- Latch the cover and inspect the spa periodically.
This checklist can help reduce the risk of freeze damage while your spa is shut down for the season.
Common Winterizing Mistakes To Avoid
- Only draining the shell. Plumbing lines, pumps, and heaters can still hold water.
- Leaving power on after draining. Pumps and heaters should never run dry.
- Forgetting pump drain plugs. Wet ends can hold water that may freeze.
- Leaving the filter wet in the spa. Clean, dry, and store filters properly.
- Ignoring blower or air lines. Some systems have hidden air channels that need attention.
- Using household soap during cleaning. Soap residue can create foam during spring startup.
- Never checking the cover during winter. Wind, snow, and damage can expose the spa.
Avoiding these mistakes can help prevent cracked plumbing, damaged pumps, heater issues, and a difficult spring startup.
Key Takeaways
- Winterizing is only needed if the spa will be shut down during freezing weather. If you use the spa all winter and can maintain heat and power, keeping it running may be better.
- Draining the shell is not enough. Water can remain inside jets, pumps, heater tubes, unions, suction lines, and plumbing manifolds.
- A wet/dry vacuum is one of the most useful tools. It can help pull or blow trapped water out of lines and fittings.
- Filters should be cleaned, dried, and stored indoors. Do not leave a dirty wet filter inside a winterized spa.
- Freeze damage can be expensive. If you are unsure how to winterize your model, hiring a qualified spa technician may be cheaper than repairing cracked plumbing later.
Winterizing a hot tub is about removing water from every place freezing temperatures could cause damage. That includes the shell, filter area, jet lines, suction lines, pumps, heater tube, unions, drain plugs, and any blower lines your spa may have.
If you decide to shut the spa down for winter, take your time and do it completely. Turn off power, drain the spa, clear the plumbing, clean and dry the shell, store the filter properly, and secure the cover. A careful winterizing routine can help protect your hot tub and make spring startup much easier.