If you’re weighing the TOTO Washlet S5 vs C5, you’re choosing between TOTO’s freshly upgraded flagship and its well-loved predecessor.
This guide breaks down every key difference so you can decide which one deserves a spot in your bathroom.
| Feature | TOTO Washlet C5 (SW3084) | TOTO Washlet S5 (SW3446) |
|---|---|---|
| Image |  |
 |
| Dimensions (L x W x H) | 20.3″ x 15.0″ x 5.75″ | 20.6″ x 15.1″ x 5.5″ |
| Water Heating | Tank (30–45 sec warm water) | Tankless (endless warm water) |
| User Presets | 2 presets | 4 presets |
| Wand Hygiene | EWATER+ | EWATER+ + CLEAN RESIN coating |
| Night Light | No | Yes |
| PREMIST Bowl Spray | Yes | Yes |
| Availability | Discontinued (limited stock) | Current model |
| Buy Now |  |
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1. TOTO Washlet C5 Elongated Bidet Seat (SW3084#01)
The TOTO Washlet C5 earned a reputation as one of the best mid-range bidet seats on the market, and for good reason.
It brought TOTO’s signature PREMIST and EWATER+ technology to a slim, modern design at a price below the premium S-series models.
If you’re exploring your options when it comes to bidets for existing toilets, the C5 set the bar that most competitors are still chasing.
Features
- Tank water heater delivering warm water for approximately 30–45 seconds per session
- PREMIST function automatically mists the bowl before each use to prevent waste from sticking
- EWATER+ electrolyzed water cleans the wand inside and out before and after every use
- Dual-action spray with oscillating and pulsating modes for rear and front cleansing
- SoftClose heated seat with five temperature settings
- Warm air dryer with five temperature settings
- Air deodorizer for real-time odor neutralization
- Slim wireless remote with illuminated touchpad and 2 user presets
- Seamless underside design for easy cleaning
- Bowl shape: elongated (SW3084#01)
Pros
- Trusted TOTO engineering with a proven track record among users
- PREMIST and EWATER+ hygiene system is genuinely effective at reducing maintenance time
- Slim 5.75″ rear profile looks clean and modern on most toilets
- Easy DIY installation with included hardware
- May be available at a discount due to closeout pricing
Cons
- Tank heater means warm water runs out quickly — a real issue for families or back-to-back users
- Only 2 user presets limits personalization in shared bathrooms
- No night light
- Officially discontinued — no manufacturer support going forward and no guarantee of long-term parts availability
- Limited remaining stock means fewer color and configuration choices
The C5 is still a fine bidet seat if you find it at a reduced closeout price and you’re the sole user in your household.
But given that it has been officially discontinued and replaced, most buyers are better served by its successor.
Check its current price on Amazon
2. TOTO Washlet S5 Elongated Bidet Seat (SW3446#01)
The TOTO Washlet S5 is TOTO’s direct replacement for the C5 and a meaningful step forward in almost every category that matters.
Named a top pick by Wirecutter, it brings tankless on-demand heating, a slimmer profile, and expanded personalization to a bidet seat that costs more but delivers noticeably more.
If you’re reading our bidet toilet seat comparison chart, the S5 consistently stands out as the best all-round mid-to-premium pick in TOTO’s lineup right now.
Features
- Tankless instantaneous water heater — no tank to run out, so every person in your home gets full warm water
- 19% slimmer rear profile (5.5″ H) compared to the C5 for a cleaner, more modern look
- PREMIST mists the bowl before use; EWATER+ cleans the wand after each use
- CLEAN RESIN antimicrobial coating on the wand and seat actively resists biofilm buildup
- Dual-action spray with soft rear, rear cleanse, and front cleanse modes plus oscillating and pulsating streams
- SoftClose heated seat with five temperature settings
- Warm air dryer (8.83 ft³/min airflow) with five temperature settings
- Built-in night light for easy nighttime navigation
- Slim wireless remote with wall-mount docking station and 4 user preset memory slots
- Energy saver mode reduces power consumption when the bathroom is idle
Pros
- Endless warm water is the single biggest upgrade over the C5 — no cold surprise mid-wash
- Four user presets make it genuinely practical in households with multiple people
- CLEAN RESIN coating means the wand stays cleaner between uses with less effort on your part
- Night light is a small addition that makes a noticeable daily quality-of-life difference
- Currently in active production with full manufacturer support and warranty
- Slimmer, seamless design looks excellent on contemporary toilets
Cons
- Higher price tag than remaining C5 stock
- Requires a nearby electrical outlet — plan accordingly if your bathroom layout is older
- Not compatible with French-curve tank toilets
The S5 is the smarter long-term buy for most households, and it is the one TOTO actively supports going forward.
If you also want to understand how the S5 compares to other brands, our guide on the best bidets for home use is a great reference point.
Check its current price on Amazon
Head-to-Head: Water Heating
This is the most important difference between the two seats, and it is not close.
The C5 uses a small onboard tank that keeps a limited amount of water warm at all times.
Once that water runs out — which happens after about 30 to 45 seconds of continuous use — you either get a cold blast or have to wait for the tank to reheat.
For a single user going through a quick routine, that is usually fine.
For families or anyone who takes their time, it can be a frustrating limitation.
The S5 uses a tankless ceramic heater that brings water to temperature in milliseconds.
There is no tank to deplete, so the warm water flows continuously for as long as you need it.
This is the same technology used in premium whole-home tankless water heaters — just miniaturized into the seat.
Winner: TOTO Washlet S5
Head-to-Head: Wand Hygiene
Both seats use TOTO’s EWATER+ system, which generates a mild electrolyzed compound from tap water to clean the wand before and after every use.
It is one of the most effective self-cleaning systems in the bidet seat category and a big reason TOTO owners tend to stay loyal to the brand.
The S5 goes further by adding CLEAN RESIN — an antimicrobial coating built into the surface of the wand itself.
This material actively repels biofilm, mineral deposits, and waste residue at a molecular level.
In practical terms, the S5 wand simply stays cleaner between deep cleans, and you’ll spend less time descaling or scrubbing.
If wand hygiene is a priority for you — and it should be — the S5 has a meaningful edge here.
Winner: TOTO Washlet S5
Head-to-Head: User Personalization
Both seats offer adjustable water temperature, pressure, and nozzle position.
The C5 stores up to two user presets on its wireless remote.
That works well enough for a single occupant but becomes awkward when two or more people share the toilet — each person has to manually re-dial their preferred settings every time.
The S5 stores four user presets, which means most households can set it and forget it.
Think of it like the driver’s seat memory on a car — once you’ve saved your settings, you get your perfect wash every single time without adjusting anything.
For seniors or anyone with limited dexterity, this kind of one-touch access to personalized settings is genuinely useful.
Winner: TOTO Washlet S5
Head-to-Head: Design and Profile
The C5 was already considered slim for its class at 5.75 inches in the rear.
The S5 shaves that down to 5.5 inches — a 19% reduction that TOTO achieved by eliminating the water tank and redesigning the housing from scratch.
The underside of the S5 is completely seamless, which makes wiping it down during your regular cleaning routine much faster.
The difference is subtle when you look at the seats side by side, but you notice it every time you glance at the toilet.
The S5 simply looks more intentional and more modern, which matters if you care about how your bathroom looks.
Winner: TOTO Washlet S5
Head-to-Head: Value
The C5 is officially discontinued, so any remaining stock you find online is a closeout situation.
That can mean lower prices, and if you spot the C5 at a steep discount, it is still a capable bidet seat for a single-user bathroom.
However, you are buying a product with no future manufacturer support, no guarantee of spare parts availability, and a heating system that has a known limitation.
The S5 costs more upfront but gives you endless warm water, more presets, a better wand coating, a night light, and the full backing of TOTO’s current warranty and service infrastructure.
Over a five-year ownership horizon, the S5 is almost certainly the better value — especially when you consider that a good bidet seat should last a decade or more.
For a broader look at what separates great bidet seats from average ones, our guide to the pros and cons of bidets covers the fundamentals worth knowing before you buy.
Winner: TOTO Washlet S5
Verdict: Which One Should You Buy?
The S5 wins this comparison clearly and consistently across every category that matters to long-term satisfaction.
That said, there are specific situations where each seat makes sense.
Buy the TOTO Washlet C5 if:
- You find it significantly discounted as remaining stock clears out
- You are the only person using the toilet and a 30–45 second warm wash is sufficient for your routine
- You are on a tighter budget and want genuine TOTO quality without paying current-generation prices
Buy the TOTO Washlet S5 if:
- You want endless warm water with no risk of a cold mid-wash surprise
- Multiple people share the toilet and benefit from individual presets
- You want a bidet seat that TOTO actively supports with warranty, parts, and long-term service
- You care about the cleanest possible wand hygiene over time
- You are building a bathroom for the long term and want to buy once and buy right
For most buyers, the S5 is the clear answer.
If you are comparing TOTO to other premium brands before making your final call, our bidet seat comparison chart covers all the major models side by side.
FAQ
Is the TOTO C5 discontinued?
Yes, the TOTO Washlet C5 was officially discontinued by TOTO in 2025 and replaced by the Washlet S5.
You may still find the C5 available through some online retailers selling off remaining inventory, but it is no longer in active production and TOTO no longer lists it as a supported current model.
The S5 (SW3446) is the recommended replacement and is currently in full production with complete manufacturer support.
Do the TOTO S5 and C5 fit the same toilets?
Both seats are designed to fit most standard North American elongated toilets with a tank that meets the bowl at roughly a 90-degree angle.
Neither seat is compatible with French-curve tanks.
You should verify that your toilet’s mounting holes are 5.5 inches apart and that there is at least 2 inches of flat space between the front of the tank and the mounting holes before purchasing either model.
Is the warm water difference between the S5 and C5 really noticeable?
Absolutely.
The C5’s tank heater provides warm water for roughly 30 to 45 seconds before you either get cold water or need to wait for reheat.
The S5’s tankless system provides continuous warm water with no time limit — the temperature stays consistent from start to finish, no matter how many times you use it back to back.
For many users, this is the single most impactful improvement the S5 makes over the C5.
Are bidets worth it compared to just using toilet paper?
Most users who switch to a bidet seat describe it as one of the best bathroom upgrades they have ever made.
A warm water wash is far more thorough than wiping, and over time you use significantly less toilet paper — which adds up to real savings.
You can read more about the long-term case in our comparison of bidets vs wet wipes and our breakdown of the pros and cons of bidet use.
Conclusion
The TOTO Washlet S5 vs C5 comparison ultimately comes down to one simple question: do you want the current model with better technology and full support, or are you willing to buy discontinued stock to save money upfront?
For most buyers, the S5 is the right call.
Endless warm water, four user presets, CLEAN RESIN wand protection, a built-in night light, and active manufacturer support make it the smarter long-term investment — even if it costs more today.
The C5 is not a bad seat, but it is a yesterday seat.
If you are still comparing options before committing, check out our roundup of the best bidets for existing toilets for a broader look at what is available right now.
You can also explore our guide to the best home bidets for more context on how the TOTO lineup stacks up against other top brands on the market.
Whatever you decide, upgrading to a bidet seat is one of those bathroom decisions you’ll wonder why you didn’t make sooner — as our readers who’ve made the switch consistently tell us.
