Hey guys, Dave here. The TOTO Washlet S5 is the seat that replaced the TOTO C5, and it fixes the C5’s biggest weakness. The C5 used a small warm water tank. The S5 uses an instantaneous heater, so the warm water keeps flowing for as long as you wash.
For most people shopping in TOTO’s middle tier, the S5 is the one I’d pick. It keeps everything I liked about the C5 and adds continuous warm water, four user presets, and a seamless seat for about $668 to $780 at Bidet King.
Some honesty up front. I installed and tested the C5 at length, I’ve tested the K300, and I owned the S550e for over a year. I have not tested the S5 myself. Everything S5-specific below comes from TOTO’s and Bidet King’s published specs. Wherever the S5 keeps a C5 trait, I’m carrying over what I saw with my own C5, and I’ll say so.
TOTO Washlet S5 Review: Quick Summary Table
The S5 is a fully loaded electronic bidet toilet seat. It has instantaneous water heating, a warm air dryer, a heated SoftClose seat, EWATER+, PREMIST, and a wireless remote. Here’s the spec sheet in one place.
| Feature | TOTO Washlet S5 |
|---|---|
| Price | About $668 to $780 at Bidet King |
| Replaces | TOTO C5 |
| Sizes and colors | Elongated (SW3446) and round (SW3445) in Cotton White; elongated in Sedona Beige |
| Heater | Instantaneous |
| Warm water | Continuous |
| Spray volume | 0.07 to 0.11 gal/min rear, 0.08 to 0.11 gal/min front |
| Spray modes | Front, rear, oscillating, pulsating |
| Water temperature | 95 to 104°F |
| Dryer | 95 to 140°F, 3 settings, 8.83 cfm |
| Heated seat | 82 to 97°F |
| EWATER+ | Yes, cleans the wand after every use |
| PREMIST | Yes, mists the bowl before use |
| Deodorizer | Automatic |
| Presets | Up to 4 users |
| Remote | Wireless multifunction |
| Nightlight | Yes |
| Power | 1,271 W rated, 1,426 W max |
| Warranty | 1-year limited |
My take on the S5 is about 4.5 out of 5. It’s the complete mainstream TOTO package. It loses half a point for the short warranty and a gentle spray that some people will find too soft.
What Changed from the C5
Three upgrades separate the S5 from the TOTO C5: an instantaneous water heater, four user memory settings, and a seamless seat. The wash, the dryer, and TOTO’s hygiene features all carry over from the C5.
The Tank Heater Gives Way to Continuous Warm Water
The C5 heated a small reservoir of water and then ran through it. When I tested the C5, that tank was the one thing I kept coming back to. The water was warm for the first stretch of a wash and then it wasn’t.
According to the spec sheet, the S5 swaps that tank for an instantaneous water heater that warms water as it passes through. TOTO lists it as continuous warm water. If you’ve ever been annoyed by a bidet water too cold halfway through a wash, this is the fix.
New Presets and Seat Design
The C5 didn’t save settings per person. The S5 remote stores user memory settings for up to four people, so each person can keep their own temperature, pressure, and position.
The seat itself is new too. TOTO calls it seamless, which means there’s no dirt gap between the top and bottom shell. On my C5 and other seats I’ve owned, that seam was the grossest spot to clean.
Plus Familiar C5 Features
Here’s what carries over from the C5 I tested:
- Front and rear wash with TOTO’s gentle aerated spray
- Oscillating and pulsating modes
- Warm air dryer and heated seat
- EWATER+ wand cleaning and PREMIST bowl misting
- Automatic deodorizer
- SoftClose seat and lid
If you want the full rundown on the old model, my TOTO C5 Washlet review covers it.
Cleansing Performance
The S5 delivers a soft, low-volume wash on paper, and I expect it to feel a lot like the C5 did. TOTO’s published spray volumes are modest, and the spray style is the same aerated design I used on the C5.
What the Published Spray Volumes Tell Us
According to the spec sheet, the S5 sprays 0.07 to 0.11 gallons per minute on the rear wash and 0.08 to 0.11 gallons per minute on the front. That works out to roughly 0.26 to 0.42 liters per minute.
Those are small numbers for a bidet toilet seat. TOTO pairs that low volume with aeration, which mixes air into the stream so it feels fuller than the raw flow suggests. You get adjustable pressure, position, and temperature, plus oscillating spray and pulsation.
The Alpha seats are the obvious contrast here. Alpha’s streams hit harder, and that’s one reason people cross-shop an Alpha JX against a TOTO. I compared the two directly in my Alpha JX vs TOTO C5 breakdown, and the alphabath smart toilet line follows the same stronger-spray approach.
How My C5 Spray Experience Informs Expectations for the S5
On my C5, the aerated spray felt pleasant and soft, more like a warm rinse than a jet. At the highest pressure it cleaned fine for me. Folks who like a firm stream wanted more.
Because the S5’s published volumes and spray style match that same TOTO approach, I’m expecting the same personality. If you loved the C5’s wash, you’ll be at home. If you thought it was weak, the S5 won’t change your mind. In that case, check your supply first, since a bidet water pressure too low problem makes any gentle spray feel worse.
Hot Water Performance
Hot water is where the S5 earns its price. It runs on instant water heating, and TOTO lists the result as endless warm water. That’s the C5’s main weakness gone.
Why the C5 Ran Cool After About 40 Seconds in My Test
When I tested the C5, the water started out at 100°F and up. That felt great. Around the 40-second mark, it started running noticeably cooler as the small tank emptied out.
For a quick rinse, 40 seconds is plenty. For a longer wash, for a second person going right after the first, or for anyone who likes to take their time, it’s a real limit. Go figure, the thing people buy a warm water seat for was the part that ran out.
What the S5’s Instant Heater Promises Instead
According to TOTO’s sheet, the S5’s instantaneous water heating warms water on demand, so it doesn’t drain a reservoir. Water temperature is adjustable from 95 to 104°F.
With no tank to empty, the second and third person in a busy morning get the same temperature as the first. I haven’t timed the S5 myself, so I can’t hand you a stopwatch number. What I can say is that the design removes the exact cause of the C5’s cool-down. If you’re curious how the two heater types differ, I explain it in how do warm water bidets work, and I round up more options in my list of best bidet seats with tankless water heaters.
Design and Dimensions
The S5 looks cleaner than the C5. TOTO slimmed the profile and smoothed out the seat, and the result reads as a premium bidet seat without much visual bulk.
Seamless Seat, SoftClose Lid, and Nightlight
The headline design change is the seamless heated SoftClose seat. There’s one continuous surface, with no gap between the seat’s top and bottom shells for gunk to settle into. The rubber bumpers underneath still need a wipe now and then.
The lid closes slowly and quietly. On my C5, I appreciated not hearing a slam at 2 a.m., and the S5 keeps that.
The S5 also adds a nightlight, which the C5 didn’t have. It’s a small thing that you’ll use every single night once you have it. The side of the seat is smooth, and the water and power connections are tucked underneath, so less hardware shows from the front.
Round and Elongated Models and Available Colors
According to the spec sheet, you’ve got these options:
- Elongated (SW3446): Cotton White or Sedona Beige
- Round (SW3445): Cotton White only
So if you have a round bowl and want beige, you’re out of luck. Shipping weight is 15.4 lbs, which is easy for one person to handle during install. Check your bowl measurements against TOTO’s dimension drawing before ordering, especially on round toilets where every inch of seat length counts.
Fit and Installation
The S5 installs like most electric bidet seats: mounting plate, water tee, plug. Before you order, confirm your bowl shape, outlet location, and water pressure, because those are the three things that cause returns.
Will the S5 Fit Your Toilet?
Pick round or elongated to match your bowl. The S5 is built to fit TOTO and non-TOTO toilets alike. Seats like this include a cutout so the water and power lines can run out the side when your toilet lacks a pass-through hole, plus a filler piece to tidy it up when you don’t need the cutout.
Skirted and one-piece toilets deserve an extra look at the mounting holes and the space behind the seat. I walk through brand-specific fit in bidets for TOTO toilets.
Outlet, Cord, Water Pressure, and Docking Requirements
Here’s the checklist from TOTO’s spec sheet:
- Power cord: 3.93 ft. That’s short. You need a grounded outlet close to the toilet, and I strongly recommend a GFCI outlet in any bathroom.
- Power draw: 1,271 W rated, up to 1,426 W. Don’t run it off a flimsy extension cord.
- Water pressure: 7.25 psi dynamic minimum, 108.75 psi static maximum. Most US homes fall comfortably inside that.
- Docking station: The seat slides onto a mounting plate and pops off with a button, which makes cleaning around the hinge area easy.
Tighten the mounting screws more than you think you need to; a loose plate means a wobbly seat. Expect the water connection to drip on the first try, so turn it on, watch, and snug it up. My guide to installing a bidet covers the full process.
Spray Features and Controls
The S5 gives you all the standard wash controls plus the remote and memory features the C5 lacked. Everything runs from one wireless remote control that hangs on the wall.
Rear and Front Wash, Oscillation, and Pulsation
According to the spec sheet, the S5 offers:
- Rear wash and front wash
- Oscillating spray, which moves the wand back and forth for wider coverage
- Pulsating spray, which varies pressure for a massage effect
- Adjustable position, water temperature, and pressure
That’s the same toolkit I used on the C5. In practice, I ended up leaving oscillation on most of the time because it covers more area with a gentle stream. Pulsation is more of a preference thing; some people love it, some never touch it.
Wireless Remote and Four User Presets
The wireless remote mounts to a wall bracket and slides off when you need it. The everyday buttons sit on the front. Less-used settings live on the back, so you’ll pull it off the wall now and then.
The big upgrade is user memory settings for up to four people. Each person saves their own temperature, pressure, and position, then hits one button. In a household with four people, that ends the “who cranked the pressure” arguments. TOTO notes that the remote’s signal depends on room layout and placement, so mount it with a clear line to the seat.
EWATER+, PREMIST and the Deodorizer
The S5 carries TOTO’s full hygiene package: EWATER+ for the wand, PREMIST for the bowl, and an automatic air deodorizer. These are the features that separate TOTO from most of its competitors.
What EWATER+ Cleans and What Still Needs Wiping
The EWATER+ self-cleaning wand gets sprayed with electrolyzed water after every use, according to TOTO. The wand also has a CLEAN RESIN coating meant to resist buildup. When I tested the C5, these features kept the wand noticeably cleaner between my manual cleanings.
EWATER+ doesn’t clean everything, though. You’ll still need to wipe:
- The seat surface and the underside bumpers
- The area around the docking plate
- The bowl itself on a normal schedule
There’s also a water filter at the inlet and an air filter on the side. Clean the water filter if spray pressure drops, and rinse the air filter every so often. My complete guide to cleaning a bidet covers the routine.
Bowl Pre-Wetting and Automatic Odor Control
PREMIST bowl wetting sprays a fine mist into the bowl before you use it. A wet surface makes it harder for waste to stick, so the bowl stays cleaner and needs less scrubbing. PREMIST technology carried over from the C5, and it worked as advertised for me there.
The air deodorizer kicks on automatically when you sit, pulling air through a carbon filter. That filter lives behind a small side compartment and needs replacing over time. It won’t eliminate every smell, but it takes the edge off.
Warm Air Dryer and Heated Seat
The S5’s dryer is one of the stronger ones in TOTO’s mainstream lineup on paper, and the heated seat covers a comfortable range. These are the comfort features that make it feel like a luxury bidet seat.
Dryer Settings, Airflow, and Realistic Expectations
According to the spec sheet, the warm air dryer runs from 95 to 140°F across three settings and moves 8.83 cubic feet per minute.
For context, the Alpha UX Pearl, which I consider the best dryer I’ve used, is rated at about 7 cfm. So the S5’s airflow number looks strong.
Now the honest note. No bidet dryer is fast. With the C5, fully drying took a couple of minutes, and most people pat dry with a square or two of toilet paper and call it good. I haven’t timed the S5. Better airflow helps, but I’d expect it to shorten that routine, not eliminate it. Hotter isn’t always better either; the highest setting gets uncomfortable quickly.
Seat Temperature and Everyday Comfort
The heated SoftClose seat adjusts from 82 to 97°F. The seat stays warm all the time unless you use the energy saver features, so it’s ready when you sit.
In winter, this was the feature my family noticed most on the C5. A warm seat on a cold morning is one of those small luxuries you stop thinking about until you use a cold toilet somewhere else. The S5 keeps that same range.
Energy Use
The S5’s instantaneous water heater only draws power while it’s heating water for a wash. That’s a big part of why tankless seats beat tank seats on efficiency: there’s no reservoir sitting there being kept warm all day.
Peak Power Versus Standby Use
According to the spec sheet, the S5 is rated at 1,271 W, with a maximum draw of 1,426 W. That max number shows up only for short bursts, mainly when the heater is warming water during a wash.
The rest of the time, the seat draws far less. The heated seat and standby electronics account for most of what it uses day to day. TOTO does not publish a monthly kWh figure for the S5, so I won’t guess one.
What Auto Energy Saver Can and Cannot Tell You About Costs
The S5 has an auto energy saver mode that learns idle periods and lowers seat heating when nobody’s using it. That cuts standby use, especially overnight or when you’re at work.
What it can’t tell you is your exact bill. That depends on:
- How many people use it
- How long each wash runs
- Your seat temperature setting
- Your local electricity rate
If you want to keep costs down, drop the seat temperature a notch and leave energy saver on.
S5 vs. S2 vs. K300
The S5 is the sweet spot of these three for most buyers. The S2 saves money by dropping the remote, and the K300 costs about the same as the S5.
Price and Feature Comparison
| TOTO S2 | TOTO S5 | TOTO K300 | |
|---|---|---|---|
| Price | About $492 | About $668 to $780 | About $699 to $725 |
| Controls | Side arm panel | Wireless remote | Wireless remote |
| User presets | Not listed by TOTO | Up to 4 | Not listed by TOTO |
| My hands-on time | None | None (C5 carryover) | Tested |
The S2 is the budget entry in the new S series. Its biggest difference is the side arm control panel in place of a wireless remote. Some people prefer an attached panel because it can’t get lost.
The K300 is a seat I’ve tested and liked a lot. You can read my full TOTO K300 review for details. Above all three sits the TOTO Washlet S7 at about $1,223, which is luxury territory.
Which TOTO Seat Makes Sense for Your Budget?
Here’s how I’d split it:
- Around $500: The S2. You get TOTO’s core wash in the new design, controlled from the side.
- $650 to $800: The S5. Continuous warm water, four presets, a remote, and the seamless seat.
- Same money, different style: The K300, if you find it on a good deal and like its look.
- $1,200+: The S7, for buyers who want TOTO’s top tier.
If you’re still on a TOTO C5, the S5 is the direct successor at the toto washlet s5 price point. For another angle on the K line, see my TOTO C5 vs K300 comparison.
S5 vs. Alpha JX2 and UX Pearl
The Alpha seats undercut the S5 on price and beat it on warranty and spray strength. The S5 answers with TOTO’s hygiene features and a stronger dryer rating.
Price, Spray Strength, and Warranty
| TOTO S5 | Alpha JX2 | Alpha UX Pearl | |
|---|---|---|---|
| Price | About $668 to $780 | About $389 | About $459 |
| Heater | Instantaneous | Tankless | Tankless |
| Spray | Gentle, aerated | Stronger | Stronger |
| User presets | Up to 4 | 2 | 2 |
| Warranty | 1 year | 3 years | 3 years |
Both Alpha seats are electronic bidet seats with endless warm water. I own and use the JX and the UX Pearl.
On the UX Pearl, I measured very low idle power with Eco mode on, and its dryer is the best I’ve used. It comes in elongated only. The JX line fits French curve toilets well and has an antimicrobial wand.
When TOTO’s Hygiene Features Justify Paying More
The S5 costs roughly $200 to $400 more than these Alphas. For that, you get EWATER+, PREMIST, CLEAN RESIN, four presets, and a round option alongside elongated.
The S5 makes sense if:
- You prioritize wand and bowl hygiene above all
- You need four separate user profiles
- You prefer a softer, gentler wash
An Alpha makes more sense if you want a firmer stream, a longer warranty, or a lower price. For a premium bidet seat under $500, the Alphas are hard to beat. More options sit in my bidet reviews.
Is the S5 the Right Upgrade From the C5?
Yes, the S5 is the right upgrade if the C5’s tank heater ever bugged you. On my C5, warm water started cooling at about 40 seconds. According to TOTO’s spec sheet, the S5’s instantaneous heater delivers continuous warm water, which removes that problem at its source.
My verdict: the TOTO Washlet S5 is worth buying for anyone who wants the complete mainstream TOTO experience, especially households sharing one seat, because it adds endless warm water and four user presets to everything that made the C5 good.
Here’s how I’d decide:
- Buy the S5 if you want TOTO hygiene, a gentle wash, and warm water that lasts.
- Pick the S2 if you’re fine with a side panel and want to save around $175.
- Pick an Alpha JX2 or UX Pearl if you want a stronger spray and a 3-year warranty for less money.
If your C5 still works and you only use quick washes, you can hold off. For everyone else shopping new, Bidet King lists the S5 at about $668 to $780, depending on size and color.
Ready to order? You can check current prices on the TOTO Washlet S5 at Bidet King here (affiliate link). Bidet King handles TOTO warranty claims and support, which is why I buy there.