TOTO K300 Review: Every Feature Tested Practically

Today, we are reviewing the TOTO K300 Washlet. I installed the bidet and used it for a while myself. I wanted to test it in various ways and to get a good idea of how it operates in the short and long.

In this article, I’ll we’ll be discussing how the bidet scored in various categories and how it compares to other bidets in the same price range.

Overall, I can’t recommend the bidet enough. It offers way more features than most bidets at this price point. For example, the TOTO C5 costs about the same while providing much less value (limited warm water, for example).

There is more than one version of the K300 and the best version (the SW3036R) is typically the same price. The other version is outdated yet still sold. So, make sure you choose the right one. You can compare prices for the version I recommend here (recommended) and also here. The least expensive option can be found here (availability varies).

Amazon is great, but you will get TOTO’s unreliable customer support through them. Bidet King has unmatched customer support. Plus, BK tends to run a lot of sales.

TOTO K300 Washlet Review: Quick Summary Table

TOTO Washlet K300 Attachment

TOTO Washlet K300 Electronic Bidet Toilet Seat, Cotton White

Feature(s)Details
Cleansing Performance Test ScoreExcellent
Water Pressure (Strength)Average
Monthly Operational Costs/Energy Use18-36 kWh ($2.00-5.00)
Warm Water SupplyEndless
Water Heater TypeInstantaneous
Round vs ElongatedElongated Only
Warm Air DryerTop Tier
Adjustable FeaturesWater Temp, Water Pressure, Heated Seat, Dryer Temp, Nozzle Position
Adjustable Nozzle Positions5
NightlightNone
Wand MaterialPlastic
Nozzle SystemSingle, 3-in-1
Nozzle SanitationSelf-Cleaning + Self-Sanitizing
Other Sanitation FeaturesPREMIST (Auto Bowl Cleaning)
Child Wash Mode ButtonNone
User PresetsYes (2)
One-Push Auto ModeNone
Air DeodorizerActive Carbon Filter
Special Spray ModesOscillation, Massage, Rear Soft
Auto Open/Close Seat and Lid FeatureNone
Sittable LidNone
Seat and Lid FeaturesSlow-Close Seat/Lid and Easy Bidet Removal
Eco Power Saving Modes4 Modes Including Smart Saver

TOTO K300 Review

Overall Performance: Exceptional

The TOTO K300 has 5 water pressure settings to adjust spray volume. The nozzle output can be adjusted from 0.07 to 0.11 gallons per minute, which comes to 0.27 to 0.43 L per minute.

As you can see, the K300 did quite well in the fake poop test. It uses far less water than most bidets on the market, yet cleans just as effectively (often better), which speaks to the efficiency of TOTO cleansing technology.

For example, here is the K300 results side by side with an entry-level bidet that sprays over twice as much water per minute (about 1L/min).

The K300 pic is a couple of inches closer, but you can still see that it sprays a wider area.

Additionally, the K300 cleans equally well compared to the S550e, TOTO’s most expensive bidet.

The efficiency is probably due to the wide range of coverage you get with the nozzle adjustment feature.

There’s no spray mode labeled “turbo” or “strong”, but the pressure is plenty adequate for basic cleansing.


Hot Water Performance: Top-Tier

Endless Warm Water

With the K300, you can choose between “Off” (cold) and 3 settings that range in temperature from 95° F to 104° F, which is about 35° to 40° C.

The K300 Washlet gets a 10/10 in this area for a few reasons. The main reason is that it has an instantaneous water heater that provides water at max temp for as long as needed.

Compare that to the TOTO C5, a similarly priced bidet, which relies on continuous heating of a small tank of water. With the C5, once the tank runs out, it has to refill and then reheat. Thus, the C5 warm water only lasts about 40 seconds.

The K300 Washlet is the least expensive TOTO bidet to have an instantaneous water heater. In case you’re new to the subject, instant heaters are among the most sought-after bidet features.

The K300 heater warms water on demand, so the bidet never runs cold.

As discussed in the section on energy efficiency, this has a major impact on how much power the bidet uses. Hence, the K300 is among the most energy-efficient bidets on the market.

TOTO Washlet K300 Attachment

TOTO Washlet K300 Electronic Bidet Toilet Seat, Cotton White


Design: Excellent

Dimensions, Different Versions, Etc.

EWATER+ (Newer)Non-EWATER+
WhiteSKU: SW3036R#01 ElongatedSKU: SW3036#01 Elongated
Sedona BeigeSKU: SW3036R#12 ElongatedSKU: SW3036#12 Elongated

See Sections Below for EWATER+ Explanation

Unfortunately, there is no round version of the bidet. If you have a round toilet, check out the S300e or S350e (article link).

Look and Feel

I really like the low-profile design of the TOTO K300.

Some of the older models like the C100 and C200 are extra-bulky in the back with a more exaggerated slope from back to front.

The K300 Washlet is only about 5” high in the rear.

Since it has an instantaneous heater, it doesn’t have to rely on housing a water tank in the back of the seat. So, you get a more streamlined, minimalist look.

The bidet is plain white (or beige) with few labels and decals, so it doesn’t stand out as much as other bidets on the market.


Basic and Advanced Spray Functions: Excellent

Front and Rear Cleansing, Nozzle Adjustment

For basic front and rear cleansing, the K300 has standard posterior and front feminine cleansing modes. There are 5 nozzle positions to choose from. This allows for custom aiming and better accuracy when cleansing.

I found I got the best coverage when using the oscillation mode (discussed below) and adjusted the nozzle position throughout the session.

Rear Soft Mode

The K300 has a Soft Rear cleansing function. Some folks prefer softer cleansing, but the feature has other uses as well. For example, it can be used for a bidet sitz bath session and to comfort irritated skin, such as with hemorrhoids.

The K300 does not, however, have an extra-soft front mode. The S500e and S300e series bidets have a Wide Front feature for softer feminine cleansing that covers a wider area.

This should not be an issue. According to my SO, the basic frontal wash feature is plenty soft enough on the lower pressure setting.

Oscillation and Massage Mode

The oscillating and pulsating functions are a nice feature.

The oscillation button triggers a back-and-forth nozzle motion that covers a larger area, which cleans more effectively.

This feature is one of the more important functions of modern electric bidets. Just imagine trying to wash dishes or your car by holding the sprayer or hose in one place.

The massage setting alternates lower and higher water pressure which is supposed to relax the muscles of the sphincters and help stimulate bowel movements. It’s a subtle feeling but it feels nice.


Controls (Wireless Remote and Auxiliary Controls): Excellent

The K300 is one of several TOTO bidets that comes with a wireless remote instead of a control panel. I.e., the controls are not fixed to the side of the seat, so there’s no need to look down and to the right to operate the bidet.

It’s a sleek and aesthetic remote with illuminated buttons. It is double-sided and doesn’t have an LCD screen.

TOTO remotes are the best. So many other brands (especially Bio Bidet) offer remotes that are super lightweight and fragile. The K300 remote has a firm, solid, and high-quality feel to it.

TOTO Washlet K300 Attachment

TOTO Washlet K300 Electronic Bidet Toilet Seat, Cotton White


Energy Efficiency: Top-Tier

If you keep the heated seat turned off, the bidet will run you only about 35 kWh per month, which means the bidet will cost a max of $5 monthly to use. On the conservative end, it could cost as little as $2.00 monthly.

Of course, it depends on the household size/number of users.

Energy-wise, the TOTO K300 Washlet is one of the more efficient bidets on the market.

First, it has a tankless heating system.

Tankless aka instantaneous water heaters only use energy when the bidet is cleansing with warm water. So, they don’t require around-the-clock electrical power to keep a tank of water warm.

The similarly priced TOTO C5 has a basic tank heater that draws power 24/7 to keep a small reservoir of water warm.

Again, for max savings, keep the heated seat powered off when the bidet isn’t in use. Sure, you won’t be able to sit down on a warm seat, but the difference between having the seat on vs off during non-use periods is quite significant as far as how much power the bidet uses.

The K300 has FOUR Different Energy-Saver Settings

  • Auto Energy-Saver mode. First, is the regular Energy-Saver mode that automatically detects times when the bidet is least likely to be used and lowers the heaters during that time. Most bidets simply turn the heater temperatures down when the user stands up, turning them back on when the user sits down.
  • Auto Energy-Saver + mode. This setting operates the same but turns the heaters off during times of infrequent bidet use.
  • Timer Energy Saver. With this setting, you can decide when you want the bidet to go into low-power mode during a certain time period—6 or 9 hours. To be used when you’re at work, sleeping, etc.
  • A setting that combines the above functions for max energy savings.  The Auto Energy Saver+ function operates outside of the time window set for the Timer Energy Saver function.

Warm Air Dryer Performance: Top-Tier

The TOTO K300 has a warm air dryer with 3 temperature settings. As you can see, the dryer works quite well. In general, TOTO blows other bidet brands out of the water with their dryer power.

And the K300 has the most powerful dryer of any TOTO bidet with an air volume of 10.24 ft3/min (0.29 m3/min). I tested the airspeed at about 1550 feet per minute.

You can adjust the temp from 95° to 140° F, which comes to about 35° to 60° C.

The K300 has no default dry session length, so simply hit the stop button when you feel dry. In the above test, I ran it for 3 minutes, the standard dry session length.

Here is how the K300 dryer compares to a less expensive Brondell Bidet.

It’s ideal if you can completely replace toilet paper with the dryer since doing so will provide the most savings. TP can cost a ton over a lifetime, so replacing paper can allow the bidet to pay for itself.

To be able to do that, it helps to have a high-quality dryer (not all bidet dryers are equal). Even with the best dryer, it will take some practice to get the most out of air drying.

Convenience Features: Average

TOTO user presets let you save water temp, pressure, and nozzle position. They don’t let you save seat surface or air temperatures.

Like all TOTO bidets, the K300 lacks a generic one-push auto function and a child wash mode.

But the convenience feature folks tend to find most useful is user presets since the feature saves you from having to choose the same settings over and over again.

User presets are especially convenient for those who will end up sharing their bidet since most bidets just remember the most recently used settings.

Also, guests can use the bidet without messing up your settings.

Anyway, it’s a great feature to have and one that’s lacking in some TOTO bidets, like the TOTO C2.

TOTO Washlet K300 Attachment

TOTO Washlet K300 Electronic Bidet Toilet Seat, Cotton White


No Nightlight

I’m not sure why, but TOTO has yet to get with the program on in-bowl nightlights. The feature seems like it would be easy and cheap enough to include in every model.

After all, bidet nightlights are a standard in the industry and even the least expensive, most entry-level bidets offered by other brands have the feature.

It makes no sense.

But alas, only the TOTO S550e and S350e offer a nightlight.


Air Deodorizer: Excellent

Like most higher-end TOTO bidets, the K300 has an air deodorizer. Air is circulated from the toilet bowl via a small fan through the filter on the left. The air then passes through the filter on the right which contains active carbon that breaks down molecules that are responsible for foul and embarrassing smells.

Clean air is then passed through the small vent on the side of the bidet to be circulated throughout the bathroom.

There are two modes: normal and power. When you sit down, the normal mode kicks on (3.17 ft3/min air volume). 10 seconds upon standing, the power mode turns on (almost twice as powerful at 5.65 ft3/min) and stays on for 60 seconds.


Sanitation: Top Tier

Here’s where the K300 really shines. It’s one of a handful of TOTO toilets to have the PREMIST function and EWATER+ nozzle sanitizing system. These features are not included with the TOTO C100, C200, A2, A100, or KC2.

Nozzle Sanitation

K300 Self-Cleaning Nozzle

EWATER+ Demo

EWATER+ is a patented solution that contains electrolytes that form NaOCl, which is short for sodium hypochlorite. NaOCl is antimicrobial and is used commonly in water treatment.

The nozzle self-rinses before and after each use and can be made to rinse on-demand.

Hence, the K300 nozzle not only self-cleans but self-sanitizes.

Auto Toilet Bowl Cleaning Feature

Next, is the PREMIST function that spritzes the bowl with EWATER+ before each use of the toilet. This keeps poop from sticking to the bowl so that the flushing action (when you flush the toilet) can better clean the toilet.

Never when using a TOTO bidet with PREMIST have I noticed waste sticking to the side of the toilet.


Cleansing Nozzle Features and Design: Average

The TOTO K300 Washlet has a single, 3-in-1 nozzle. So, instead of the dual nozzle setup that’s common with some bidets (Brondell and Omigo), a single nozzle cleanses the entire perennial region.

This is the ideal nozzle system in terms of efficiency since there are fewer moving parts.

On the downside, there is no specialized frontal cleansing feature (dispersed holes). Also, the nozzle is made of plastic. TOTO nozzles aren’t known for breaking but I do know a lot of bidet users who prefer stainless steel.


Comfort (Heated Seat, Sitting Room, Etc.): Excellent

Heated Seat

The heated seat is really comfortable. It only ever felt too warm when sitting for longer periods at the max temperature setting.

You can adjust the temperature from 82° to 97° F, or around 28° to 36° C.

Sitting Room

As mentioned in the design section above, the K300 is non-bulky so there is less of a slope from back to front. So, I never felt that I was pushed to the front of the seat and always felt that I had enough room.


Other Seat and Lid: Average

No Sittable Lid

As with all TOTO bidets, there is no sittable lid. So, if you like to use your toilet as a seat for non-toileting purposes, you’re out of luck with this bidet.

This matters for some folks who like to sit for clipping toenails, resting, etc.

The K300 doesn’t have the auto open/close feature of the S300e and S500e series bidets.

Soft Close Feature

But it does have the SoftClose feature which prevents wear and tear.

Just give the seat and lid a small nudge and they lower slowly and quietly. No slamming.

The bidet has a quick-release tab so that you can easily remove and reinstall the bidet for cleaning or when moving.


TOTO K300 Washlet Review: Conclusion

There you have it.

I definitely recommend the bidet. It is about 3 features shy of the S550e (TOTO’s best bidet) yet costs about half the price. And the three features it is missing are relatively small and unimportant (e.g., the nightlight).

On the other hand, the high-end heater alone makes the K300 far better than the C5. Yet, the K300 is close to the C5 in price (a bit more, but not much).

As mentioned in the intro, there is more than one version of the K300 and the newest version is the best. The older model is still for sale, so make sure to get the correct one. You can compare prices for the version I recommend here (recommended) and also here.

Amazon is great, but Bidet King has unmatched customer support (you’ll get TOTO’s lackluster customer support through Amazon). Plus, BK tends to run a lot of sales.

5/5 - (3 votes)

Leave a Comment