How to drain a hot tub

To drain a hot tub, turn the power off at the breaker, then either attach a garden hose to the built-in drain spigot (1 to 2 hours) or drop in a submersible pump (15 to 30 minutes). Send the water to your lawn or a sanitary sewer cleanout after letting the sanitizer fall near zero. Clean the shell and filter, then refill through the filter compartment.

Before you drain

• Stop adding sanitizer 2 to 3 days ahead and leave the cover off for a few hours on the day. You want chlorine or bromine near zero and pH roughly 7 to 8 before the water goes on the ground.
• Check local rules. Many towns prohibit draining to the street or storm drain.
• Pick the weather. Above freezing, and not in blazing sun. An empty acrylic shell should not bake uncovered for hours.
• Plan the refill. Have balancing chemicals, a clean or new filter, and test strips ready.
• Flush the lines. This is the one chance to clean the plumbing. Add a line flush product and circulate it per the label before draining. See hot tub line flush.

Two ways to drain

	Built-in drain spigot	Submersible pump
Time for 400 gallons	1–2 hours	15–30 minutes
Cost	Free	A utility pump and hose
Effort	Connect hose, open valve, wait	Place pump in footwell, run hose, watch it
Gets the last water out	Usually leaves an inch or so	Leaves an inch or so
Best for	No rush, downhill drainage	Cold weather, flat yards, saving time

Step by step

1. Turn off power at the breaker or disconnect. Not just the topside panel. The heater and pumps must not be able to start.
2. Remove the filter. Set it aside for a deep clean or replacement.
3. Drain the water.
   • Spigot: find the drain at the base of the cabinet, often behind a small door or cap. Pull it out if it is the pull-and-twist type, remove the cap, thread on a garden hose, and open the valve. Run the hose downhill.
   • Pump: put the pump at the lowest point of the footwell, lay the discharge hose to your drain spot, and plug the pump into a GFCI-protected outlet. Stay nearby and unplug it as soon as it starts sucking air.
4. Remove the last water. Use a wet/dry vacuum, a sponge, or towels for what is left in the footwell and seats.
5. Clean the shell. Wipe it with a spa surface cleaner or a soft cloth and plain water. Avoid household cleaners. Their residue makes foam. Rinse and wipe dry.
6. Clean the filter. Soak it in filter cleaner or install a new one. See how to clean a hot tub filter.
7. Close the drain. Shut the valve, remove the hose, and replace the cap. A forgotten open drain is the classic refill mistake.
8. Refill. Put the hose in the filter compartment so water fills the plumbing from the bottom and pushes air out. Fill to above the highest jets.
9. Restore power and start up. Follow hot tub startup after draining for priming, balancing, and heating.

Where the water should go

• Your lawn or landscaping, spread around so it soaks in. Dechlorinated, pH-neutral spa water is fine for grass. Keep it away from vegetable beds, ponds, and your neighbor's yard.
• The sanitary sewer, through a cleanout or a utility sink, if your municipality allows it. The sewer goes to a treatment plant.
• Not the storm drain. Storm drains usually run straight to streams. Many places fine for this.
• Salt systems: salty water can harm plants. Use the sewer where allowed.

Things that go wrong

• Drain is very slow. Gravity drains are slow by nature. Check for a kinked hose and make sure the hose end is lower than the drain. A pump is the fix.
• Drain spigot drips afterward. The valve was not fully closed or the cap gasket is missing. Replacement drain valves are a common, inexpensive part.
• Pumps hum and no water moves after refill. That is an air lock. The startup guide shows how to bleed it.
• Error code after refill. Usually air in the heater. On Balboa systems you may see dr or a flow message. Bleed the air and reset.

How often to drain

Every 3 to 4 months for most households, sooner with heavy use. The common rule of thumb is gallons divided by 3, divided by the number of daily bathers, equals days between changes. Details in how often to change hot tub water.

Do not leave it empty

Refill the same day. Water left in low spots of the plumbing grows bacteria in a drained tub, seals can dry out, and in winter those pockets freeze and crack fittings. If the tub must sit empty for weeks, follow the winterizing steps to get the water out of the lines.