Choosing between the TOTO WASHLET A2 and S2 can be tricky when both look similar on the surface.
You’ll find that these two bidet seats sit in very different leagues once you dig into what each one actually offers.
| Feature | TOTO WASHLET A2 (SW3004) | TOTO WASHLET S2 (SW3346) |
|---|---|---|
| Image |  |
 |
| Dimensions (L x W x H) | 20.94″ x 18.63″ x 6.63″ | 20.94″ x 18.50″ x 5.30″ |
| Water Heating | Tank (limited warm water) | Instantaneous (unlimited) |
| Warm Air Dryer | No | Yes (3 temp settings) |
| PREMIST | No | Yes |
| EWATER+ Wand Cleaning | No | Yes |
| Night Light | No | Yes |
| Deodorizer | No | Yes |
| Buy Now |  |
 |
1. TOTO WASHLET A2 Electronic Bidet Seat (SW3004)
The TOTO WASHLET A2 is the brand’s entry-level seat, designed for anyone who wants genuine WASHLET quality without the full feature set of higher models.
It delivers warm water cleansing, a heated SoftClose seat, and a side-arm control panel — everything you need for a solid bidet upgrade.
Features
- Gentle aerated dual-action spray with oscillating option
- Adjustable water temperature (3 settings) and pressure (5 levels)
- Heated SoftClose seat and lid (3 temperature settings)
- Convenient side-arm control panel with illuminated buttons
- Self-cleaning wand (cleans before and after each use)
- Quick-release docking station for easy cleaning
- Compatible with WASHLET+ and most standard toilets
Pros
- Affordable entry point into TOTO’s WASHLET lineup
- Simple, intuitive controls — great for first-time users
- Reliable build quality backed by TOTO’s reputation
- DIY installation in under an hour
- Fits most elongated toilets right out of the box
Cons
- Tank water heater means warm water runs out after roughly a minute of continuous use
- No warm air dryer — you’ll still need toilet paper for drying
- No PREMIST, EWATER+, night light, or deodorizer
- Taller profile than the newer S2
If you’re new to bidet seats and want to experience TOTO quality on a budget, the A2 is a dependable, fuss-free choice that covers the basics beautifully.
As noted in our bidet vs washlet guide, the WASHLET format is ideal for anyone who doesn’t want a separate fixture eating up bathroom space.
Check its current price on Amazon
2. TOTO WASHLET S2 Electronic Bidet Seat (SW3346)
The TOTO WASHLET S2 is the brand’s newest entry-level seat, replacing the older C2 with a major feature upgrade and a 19% slimmer profile.
It brings instantaneous water heating, PREMIST, EWATER+, a warm air dryer, night light, and deodorizer — features once reserved for much more expensive models.
Features
- Instantaneous tankless water heating for unlimited warm water
- PREMIST wets bowl before use, reducing waste adhesion
- EWATER+ electrolyzed water sanitizes wand before and after each use
- Warm air dryer with 3 temperature settings
- Automatic deodorizer activates after each use
- Built-in night light for low-light bathroom visits
- Front, rear, soft rear, and oscillating spray modes
- Heated SoftClose seat (3 temp settings), side-arm control panel
- Eco mode reduces energy consumption during idle periods
- 19% slimmer than the previous generation
Pros
- Unlimited warm water — never runs cold mid-use
- PREMIST and EWATER+ provide a far more hygienic experience
- Built-in dryer means truly paper-free use
- Sleeker, more modern profile suits contemporary bathrooms
- Night light is a practical bonus for nighttime bathroom trips
- Eco mode keeps running costs low
Cons
- Higher price point than the A2
- No wireless remote — side arm panel only (step up to S5 for remote)
- Requires a GFCI-protected outlet (20-amp circuit recommended)
The S2 is what you get when TOTO brings its best mid-range technology down to a genuinely accessible price tier.
If you’ve been exploring options across the bidet toilet seat comparison chart, you’ll notice the S2 punches well above its price point in terms of features.
Check its current price on Amazon
Water Heating: The Biggest Difference Between A2 and S2
This is where the two seats diverge most dramatically, and it’s the single most important factor in your decision.
The A2 uses a tank heating system, which stores a small reservoir of warm water.
That reservoir runs out after roughly 60 seconds of continuous use — meaning longer sessions will end in cold water.
The S2 uses instantaneous tankless heating, delivering endless warm water no matter how long you use it.
For most users, this alone makes the S2 the more satisfying day-to-day seat.
If you’ve ever felt the jarring switch from warm to cold water mid-use, you’ll understand exactly why this matters.
Winner: S2
Hygiene Features: PREMIST and EWATER+ vs Basic Self-Clean
The A2’s wand cleans itself before and after each use using regular water — a solid baseline, but that’s where it stops.
The S2 takes hygiene several steps further.
PREMIST sprays the bowl surface before you use it, creating a layer of water that prevents waste from sticking to the ceramic.
EWATER+ transforms ordinary tap water into an electrolyzed, mildly sanitizing solution that cleans the wand inside and out — no chemicals, no cartridges.
This means every part of the S2’s cleaning process is more hygienic than the A2’s, both for you and for the seat itself.
As discussed in our article on whether bidets get poop on them, a self-sanitizing wand is one of the most important features to look for.
Winner: S2
Drying and Deodorizing: A2 Falls Short Here
The A2 has no warm air dryer and no deodorizer.
After washing, you’ll need toilet paper or a towel — which somewhat defeats the paper-free purpose of a bidet seat.
The S2 includes a warm air dryer with three temperature settings and an automatic deodorizer that kicks in after each use.
If your goal is a fully hands-free, paper-free bathroom experience, only the S2 can deliver that.
Check out our guide to the best bidets for home use to see how the S2 compares to other paper-free options on the market.
Winner: S2
Design and Profile: S2 Is the Slimmer, More Modern Seat
The A2 measures 6.63″ in height, giving it a noticeable bulk on top of the toilet bowl.
The S2’s redesigned tankless body is 19% slimmer, sitting lower and blending more naturally with modern toilet aesthetics.
Both seats use the same side-arm control panel format, making the control experience identical.
Neither offers a wireless remote — if that’s important to you, you’d need to step up to TOTO’s S5 model.
For most bathrooms, the S2’s slimmer look is simply a better fit.
Winner: S2
Value: Which One Makes More Financial Sense?
The A2 costs less upfront, and for a tight budget it’s a legitimate entry point into TOTO’s ecosystem.
But the gap in features between these two seats is enormous relative to the price difference.
The S2 adds unlimited warm water, PREMIST, EWATER+, a dryer, a deodorizer, a night light, eco mode, and a slimmer profile — all for a moderate premium over the A2.
When you factor in the long-term savings from going paper-free (our popularity guide notes that bidets can significantly reduce annual toilet paper spend), the S2’s dryer pays for itself faster.
For most buyers, the S2 represents far better value at its price point.
Winner: S2
Verdict — Which One Should You Buy?
Buy the TOTO WASHLET A2 if… you want the lowest possible entry point into TOTO’s WASHLET range, you’ll use the seat for short sessions only, you don’t mind using toilet paper to dry off, and you prioritize price above all else.
Buy the TOTO WASHLET S2 if… you want unlimited warm water, you’re aiming for a truly paper-free bathroom, hygiene features like PREMIST and EWATER+ matter to you, or you simply want the best value seat in TOTO’s current lineup.
The S2 wins this comparison convincingly across nearly every category.
It’s not just a modest upgrade over the A2 — it’s a fundamentally different (and better) seat at a price that’s still very reasonable.
If you want to go deeper on the TOTO range before deciding, our best bidet brands guide covers where TOTO sits relative to the competition.
FAQ
Is the TOTO WASHLET A2 being discontinued?
The A2 (SW3004) is currently available and actively sold.
However, TOTO has been refreshing its lineup — the S2 now replaces the older C2 as the brand’s go-to entry-level instantaneous heating model, so the A2 occupies a slightly lower budget tier.
Does the TOTO WASHLET S2 require a special electrical outlet?
Yes — the S2 draws significantly more power than the A2 due to its instantaneous water heater (up to 1,428W at peak).
TOTO recommends a dedicated 20-amp GFCI-protected circuit for the S2.
The A2 (287W peak) will typically work on a standard GFCI outlet without a dedicated circuit.
Can I install either seat on a round toilet?
Both the A2 and S2 are available in elongated and round versions.
The elongated models (SW3004#01 and SW3346#01) are compared in this article.
For round toilets, look for the SW3003#01 (A2) and SW3345#01 (S2) variants.
Our guide to the best bidets for round toilets is a helpful resource if your bathroom has a compact, round bowl.
Which seat is better for seniors?
The S2 is the stronger choice for seniors, thanks to its night light (safer nighttime trips), warm air dryer (less need to reach and twist), deodorizer, and unlimited warm water.
Our dedicated guide on the best bidets for seniors covers more options suited to older users and those with limited mobility.
Conclusion
The TOTO WASHLET A2 is a reliable, no-frills seat that serves well as a first step into bidet living.
But the S2 is a genuinely superior seat in almost every measurable way — better water heating, better hygiene, a dryer, a deodorizer, a night light, and a slimmer modern design.
Unless your budget is the deciding factor, the S2 is the smarter long-term investment.
It brings features you’ll appreciate every single day, and it does so at a price that remains competitive with the broader market.
Whether you go with the TOTO A2 or the TOTO S2, you’ll be upgrading your bathroom hygiene well beyond what toilet paper alone can offer.
For more help finding the perfect seat, explore our bidet toilet seat comparison chart or browse our picks for the best bidets for existing toilets.
