TOTO WASHLET K300 SW3036 Toilet Seat Review

The TOTO WASHLET K300 (model SW3036) is a slim, elongated bidet seat that combines instant water heating with a wireless remote, a heated seat, a warm-air dryer and TOTO’s PREMIST bowl pre-mist. It sits below TOTO’s top-tier seats but includes the feature most shoppers care about: warm water that doesn’t run out. As of November 2026, TOTO’s product page for the K300 still shows SKU SW3036, but with a “limited inventory” notice and no retailers listed, which suggests it is being phased out.

This review is based on TOTO’s spec sheet and product page; we have not physically tested the seat (see our methodology). We cover what the K300 offers, how the SW3036 differs from the later SW3036R, and what to buy if you can’t find one.

Is the TOTO K300 SW3036 still available?

TOTO hasn’t removed it, but the signs point to the end of its run. The K300 product page on TOTO’s site lists SKU SW3036 with a “limited inventory” banner, meaning it may not be available from all suppliers, and the retailer list was empty when we checked in November 2026. TOTO’s main WASHLET page still names the K300, but its lineup is now led by newer seats such as the S7A, S7, S5 and C2.

TOTO also published a spec sheet for a revised model, the SW3036R. It keeps the K300’s core features and adds EWATER+, which TOTO says auto-cleans the wand, plus an on-demand wand-cleaning button on the remote. If you see both model numbers listed, the SW3036R is the newer one.

SW3036 vs. SW3036R

Feature	SW3036	SW3036R
Instant water heating	Yes	Yes
Dryer settings	3	3
Remote with 2 user settings	Yes	Yes
PREMIST	Yes	Yes
EWATER+ wand cleaning	No	Yes, plus on-demand cleaning from the remote

Both spec sheets list the same 120V power rating, 3.94-ft cord and elongated shape.

Key features, according to TOTO

Washing

TOTO describes a “gentle aerated, warm water, dual action spray” with an oscillating feature. The spec sheet lists four spray types: rear, rear soft, front and wide front. Water temperature and volume are adjustable, and spray temperature ranges from about 86 to 104°F.

Instant water heating

The K300 heats water as it flows rather than storing it in a tank. TOTO says this gives continuous warm water and saves energy because there is no tank to keep warm. The trade-off is higher peak power: the spec sheet lists 1274W rated and 1430W maximum, which is why a dedicated, properly protected outlet matters.

Comfort and control

• Heated seat with temperature control, about 82 to 97°F.
• Warm-air dryer with three temperature settings.
• Automatic air deodorizer.
• PREMIST, which mists the bowl with water before each use.
• Slim wireless remote with illuminated buttons and two user settings.
• Docking station that TOTO says makes installation and cleaning easier.

TOTO doesn’t list an automatic lid, night light or EWATER+ for the original SW3036.

Energy saving and upkeep, per TOTO’s manual

Three energy saver modes

The K300’s owner’s manual describes three ways to cut standby energy. Auto energy saver takes about 10 days to learn the times when the toilet is rarely used, then lowers the seat temperature during them. Auto energy saver+ is designed to save more energy than the standard auto mode. Timer energy saver lets you set a daily window for the seat heat to drop or switch off. Even with a saver on, TOTO says the seat comes back up to temperature in about 15 minutes.

Routine care

• Wand cleaning. A wand cleaning function extends the wand so you can wipe it.
• Deodorizing filter. The manual includes a section on cleaning the deodorizing filter.
• Water filter drain valve. TOTO explains how to clean the filter in the drain valve and warns not to remove it while the water is on.
• One-touch removal. The main unit can be removed for cleaning, and the lid is removable.
• Remote batteries. The remote runs on two AA alkaline batteries; replace both at once.
• Freeze protection. If the bathroom could freeze, TOTO says to keep the room warm or drain the water.

Our maintenance checklist turns these into a simple schedule.

Pros and cons

Who it’s for

• TOTO fans who want instant heating without paying for top-tier extras like an automatic lid.
• Owners of elongated toilets who like a low, slim seat profile.
• Existing K300 owners looking for documentation on their seat.

It isn’t for round bowls, and with stock now limited, it isn’t the easiest seat to buy new.

What to check before you buy

1. Exact model number. SW3036 is the original; SW3036R adds EWATER+ wand cleaning. The suffix #01 is Cotton white and #12 is Sedona Beige.
2. Bowl shape and fit. The K300 is elongated only. TOTO says it fits most existing toilets but recommends checking its WASHLET fit chart. Our measuring guide covers the basics.
3. Power. The cord is 3.94 ft long. TOTO strongly recommends a surge protector. If you have no outlet near the toilet, have a licensed electrician install a GFCI-protected outlet.
4. Water. TOTO lists supply pressure from 7.25 PSI (dynamic) to 108.75 PSI (static) and says to use potable water only, not recycled water.
5. Seller and warranty. With limited inventory, buy from a seller who can confirm the unit is new and covered by TOTO’s one-year limited warranty.

For installation steps, see our smart toilet seat installation guide.

Current alternatives

If you can’t find a K300, these seats are current on their makers’ sites. Within TOTO, the WASHLET S7A is the step up, adding an automatic lid and EWATER+ for the wand and bowl, though it also fits elongated bowls only. TOTO’s S5 (SW3446) is another tankless option with EWATER+ and four user memories, but TOTO also marks it limited inventory. Outside TOTO, the Brondell Swash 1400 offers tankless heating with separate front and rear nozzles, in round or elongated sizes.

Best for: Premium, hands-free features Electric bidet seat

TOTO WASHLET S7A

SW4736 (Contemporary, elongated)

TOTO’s upper-tier WASHLET with an automatic opening and closing lid, instant water heating and EWATER+ cleaning of the wand and bowl.

• Automatic open/close lid
• Instantaneous (tankless) water heating
• EWATER+ and PREMIST bowl pre-mist
• Warm-air dryer with 5 settings; auto deodorizer
• Remote with dock and 4 user memories

Check first: Elongated bowls only; needs an outlet near the toilet.

Check Price on Amazon for TOTO WASHLET S7A (opens Amazon in a new tab)

Researched, not hands-on tested Specs checked against the manufacturer’s page, November 2026.

Specifications from manufacturer product pages, checked November 2026. Models and availability change — confirm details on the listing before you buy. No prices are shown because they change frequently.

For more options by need, see our best bidet toilet seats roundup.

Frequently asked questions

What is the difference between the TOTO SW3036 and SW3036R?

According to TOTO’s spec sheets, both are the K300 with instant water heating, a three-setting dryer and a two-user remote. The SW3036R adds EWATER+ automatic wand cleaning and an on-demand wand-cleaning function on the remote.

Does the K300 fit round toilets?

No. TOTO describes the K300 as a slim, elongated seat design.

Is the K300 tankless?

Yes. TOTO’s spec sheet lists an instant water heating system for continuous warm water.

Bottom line

Compare TOTO with other brands in our best smart toilet seats of 2026, or browse more reviews.