How to winterize a hot tub comes down to this: switch off the power, drain the tub completely, clear the water out of the plumbing lines with a shop vacuum, clean and dry the filters, and close the tub with a locked, well-fitted cover. In freezing climates, water left in the pump, heater and pipes will freeze and can crack them, so the draining and line-clearing steps matter more than anything else. If your tub stays in use all winter, you don’t need to winterize it, but you do need to keep it heating and powered.
Winterize or keep running: which is right?
If you use the tub through winter, keep the water warm, covered and circulating, and check it often, because a power cut can let a tub freeze. If you won’t use it for weeks, or you will be away, winterizing is the safer choice. A tub that is half-drained or left cold with water in the lines is the worst option.
What you need
- A garden hose or a submersible pump to drain the tub.
- A wet/dry shop vacuum that can blow as well as suck.
- Towels, a clean bucket and a filter cleaner.
- Your owner’s manual for the drain location and any model-specific steps.
- A winter cover or tarp if your hard cover needs extra protection.
How to winterize a hot tub, step by step
1. Turn off the power
Jacuzzi’s guide puts it first: turn off the breaker and remove the outside disconnect, so the tub cannot be switched on by accident while it is empty. Running a heater or pump dry can ruin them.
2. Drain the water
Use the tub’s drain with a garden hose, or a submersible pump if there is no drain. Drain until nothing more comes out, and follow your manual if you can’t find the drain.
3. Remove the filters
Take the cartridges out, clean them and let them dry completely. Jacuzzi suggests replacing filters that are more than a year old rather than storing them. Our guide to how to clean a hot tub filter shows how.
4. Clear the water from the lines
Draining the tub leaves water in the plumbing, pump housing, filter canister and heater. Jacuzzi says to use the shop vacuum to remove what remains, and to blow air through the piping. Work through each jet, the footwell and filter area, and any drains until you see only air. Some owner’s manuals also say to leave drain caps off so any last moisture can evaporate, so check yours.
5. Dry the shell and equipment bay
Wipe water out of the footwell, seats and around the jets. Open the equipment compartment and check the pump and heater for drips. Keep it dry.
6. Cover the tub
Fit the hard cover and lock it. Jacuzzi suggests adding a tarp or winter cover over it to keep water out and to protect a wooden cabinet, and insulating the cabinet or equipment compartment. Snow load can crush a poor cover, so clear heavy snow when it is safe to do so.
7. Treat the water only if you leave water in
If you do leave water in the tub for the winter, Jacuzzi suggests winterization chemicals to balance the water and protect the plumbing. Use products as labeled, never mix them, and check your manual first.
Keeping a hot tub running through winter instead
Leave the cover on whenever you aren’t using the tub, and check the water level and heater regularly. Keep the filters clean, since flow problems stop heaters in cold weather. If the power may go out for long, plan to drain the tub rather than risk a freeze. Our guide to hot tub covers explains what to look for in a cover that keeps heat in and snow out.
Common winterizing mistakes
- Draining the tub but leaving water in the lines.
- Leaving a wet filter in a closed tub, where it grows mildew.
- Using household antifreeze in the plumbing.
- Covering a tub that is still full of stale water.
- Forgetting to switch the breaker off.
Opening it again in spring
Refit the filters and drain caps, close the drains, refill with a hose through the filter opening to reduce air pockets, restore power and check for leaks before heating. If the tub won’t heat afterwards, see hot tub repair. If you are closing a pool as well, our guide on how to close a pool for winter covers that side.
Signs your hot tub has frozen
If a tub was left with water in it during a hard freeze, look for cracks or drips before you restart it. Common signs include water around the equipment bay, a pump housing or union that is split or weeping, a heater housing that leaks, jets that no longer pulse or a pump that runs but moves no water. If you suspect freeze damage, leave the power off and have a technician inspect the equipment, because running a damaged pump or heater can make the damage worse.
A simple winterizing checklist
| Step | What to do | Why |
|---|---|---|
| Power | Switch off the breaker and the outside disconnect | So the tub can’t start while empty (Jacuzzi) |
| Drain | Drain the tub completely, including footwell and seats | Water left in the shell can freeze |
| Filters | Clean and dry them, or replace worn ones | Jacuzzi suggests replacing filters over a year old |
| Lines | Use the shop vacuum on every line, jet, filter well and the heater housing | Draining leaves water in the plumbing |
| Cover | Lock it, add a tarp or winter cover and insulate the cabinet | Keeps water out and protects the cabinet (Jacuzzi) |
| Check | Look at the tub after storms and heavy snow | A failed cover lets water in |
Cabinet, cover and surroundings
Moisture is the long-term enemy of a drained tub. Keep the cover in good shape, because a torn or waterlogged cover lets rain and snow in and loses its seal. Keep the area around the tub clear so snow doesn’t pile against the cabinet, and make sure animals can’t get into the equipment bay. If your tub sits on a deck or pad, check that it stays level and that water can drain away from it.
Frequently asked questions
Do I need to winterize my hot tub?
If it will sit unused in freezing weather, yes. Water left in the pump, heater and pipes can freeze and crack them. If you keep using it and it keeps heating, you can leave it running.
Can I use antifreeze in my hot tub?
Don’t use automotive antifreeze. Follow your manufacturer’s winterizing instructions, and check your manual before using any product in the plumbing.
Do I have to blow out the lines?
Draining alone leaves water in the plumbing. A shop vacuum used to blow and suck the lines removes the rest, which is why manufacturers recommend it.
Can I leave water in my hot tub over winter?
You can if the tub stays powered and heating, with a good cover and regular checks. If power might fail, drain it.
Sources
Always check the manual for your exact model. These manufacturers and public agencies are good places to confirm the details that apply to your equipment.