Smart Toilets & Power Outages
Yes, you can almost always flush a smart toilet during a power outage. Most models include a mechanical hand lever or a battery-powered emergency flush built in for exactly this. Find and use that backup, and the toilet flushes normally. The bidet spray, heated seat, warm air dryer, and auto-open lid stay off until power returns.
The one thing your smart toilet still needs is water pressure. Electricity and water are separate utilities, so an outage usually doesn't stop your water. (If you live in a high-rise with an electric water pump, pressure can drop too.) As long as water still flows from a faucet, your emergency flush will work.
The catch is that every brand hides its backup in a different spot, with different steps. Below we cover the three common types and walk through the big brands, plus a universal bucket-pour method that works on any toilet if all else fails.
See smart toilets with manual-flush backup.
See our picks →
What still works (and what doesn't) when the power goes out
When the power drops, your smart toilet splits into two halves. The flush almost always keeps working through a backup, but every electric comfort feature shuts down until power returns. Working in an outage (via backup): flushing, and on most models the basic fill and bowl function. NOT working until power is back: the bidet wash spray, water heating, seat warmer, warm-air dryer, deodorizer, nightlight, auto-open/close lid, remote control, and the touch sensors. Your remote and seat sensors usually go dead, which is exactly why a manual lever or button exists. Don't keep tapping a dead remote and assume the toilet is broken. Once electricity comes back, do one normal flush right away to clear anything left in the drain line.
The three kinds of emergency flush
Smart toilets handle outages in one of three ways, and knowing which one you have tells you what to look for. 1) Mechanical hand lever (e.g. TOTO Washlet and Neorest): a hidden physical lever, usually on the side of the unit, that flushes with no electricity at all. 2) Battery backup (e.g. Kohler Numi): the toilet runs on AA batteries during an outage so the touch-button flush still works, often for dozens of flushes. 3) Built-in backup battery (most tankless models, like Woodbridge and Bio Bidet): a small rechargeable battery powers a limited number of power-outage flushes automatically. If none of these are available or the battery is dead, every toilet can still be flushed manually with a bucket of water.
How to find your toilet's manual flush
Before an outage hits, locate your backup once so you're not hunting in the dark. Common spots to check, in order: the right or left SIDE of the seat unit, where a small lever may pull or fold out; a small panel or cover near the base or back of the toilet that hides a button or battery tray; the rear corner of the unit where the water line connects. On many models the manual lever is recessed and easy to miss, so run your fingers along the sides. The fastest shortcut is your owner's manual: search the model number plus 'power outage' or 'emergency flush.' Tip: stick a small note or a flashlight nearby so anyone in the house knows where the backup is.
TOTO Washlet and Neorest: pull the hand lever
TOTO integrated toilets use a true mechanical lever, so they flush even with zero power. Steps: 1) Find the hand lever on the right side of the Washlet's main body and pull it out. 2) Pull the lever DOWN and hold it for about 4 seconds or longer. 3) When the flush finishes (about 4 seconds), release the lever. 4) Return the lever to its original position. One catch: right after a flush the tank refills, which can take up to about 60 seconds, and you can't flush again until it's full. If nothing happens, wait a minute and try again. When power is restored, do one normal flush to make sure nothing stays in the drainpipe.
Kohler Numi and other battery-backup models
The Kohler Numi doesn't use a mechanical lever. Instead it runs on AA batteries during an outage so the touch-button flush keeps working. The Numi holds eight AA batteries and supports roughly 100 flushes on them. The batteries aren't needed for everyday use, so many owners only install them when the power actually goes out. To be ready: keep eight fresh AA batteries in the bathroom, learn where the battery compartment is on the unit ahead of time, drop them in when an outage starts, and flush using the normal button. If you skip the batteries, fall back to the bucket-pour method. Replace the batteries afterward so you're covered for next time.
Tankless smart toilets (Woodbridge, Bio Bidet) and the universal bucket method
Many tankless one-piece smart toilets advertise a 'power outage flush' that runs off a built-in rechargeable backup battery, so a few flushes happen automatically by pressing the flush button or its dedicated outage button. Check your manual for how many backup flushes you get, since the battery is limited. When the backup battery is drained, or on any toilet without one, use the universal bucket method: fill a bucket with water, then pour about 1 to 1.5 gallons quickly and directly into the bowl. The fast rush of water triggers a gravity flush. For a heavier load you may need closer to 2 gallons. This works on any toilet as long as you have water on hand.
Tips & warnings
- Find your emergency flush BEFORE you need it: locate the lever, button, or battery tray now and tell everyone in the house. Hunting for it in the dark is the real headache.
- Keep a stash of spare batteries (eight AA for the Kohler Numi) in the bathroom cabinet so a battery-backup toilet is always ready.
- Store a bucket and a few gallons of water nearby if you're in an outage-prone area, this is the one method that works on every toilet.
- When power returns, run one normal flush right away to clear the drainpipe, then check that the heated seat, bidet, and dryer all power back on.
Frequently asked questions
Can you flush a smart toilet without power?
Almost always, yes. Most smart toilets include an emergency flush, either a mechanical hand lever or a battery backup, so the toilet flushes normally during an outage. The bidet spray, heated seat, and dryer stay off until power returns. As a last resort on any toilet, pour about 1 to 1.5 gallons of water quickly into the bowl to force a flush.
Where is the manual flush button on a smart toilet?
It varies by brand, but check the right or left side of the seat unit first, then any small panel near the base or back of the toilet. TOTO models use a pull-down hand lever on the right side of the main body. Battery models like the Kohler Numi use the normal flush button once AA batteries are installed. When in doubt, search your model number plus 'emergency flush.'
Will the bidet and heated seat work during a power outage?
No. The bidet wash, water heating, warm air dryer, seat warmer, deodorizer, nightlight, and auto-open lid all need electricity and will not work until power comes back. Only the flush is designed to keep working in an outage, through the toilet's mechanical lever or backup battery.
Do smart toilets still flush if I have no water pressure?
No. The emergency flush still needs water in the line. Electricity and water are separate utilities, so an outage usually doesn't affect your water. But if your home relies on an electric well pump or a high-rise booster pump, an outage can also cut water pressure. If a faucet still runs, your toilet can flush.
How many flushes do I get on the backup battery?
It depends on the model. The Kohler Numi supports roughly 100 flushes on eight AA batteries. Tankless models with a built-in rechargeable backup typically give you only a handful of flushes, so check your manual. Once the battery is drained, switch to the bucket-pour method to keep flushing.