Choosing between the Kohler C3 325 and C3 455 — now rebranded as the PureWash E815 and PureWash E820 — is one of the most common dilemmas you’ll face when shopping for a premium bidet seat.
Both are excellent seats from one of the most trusted names in bathroom fixtures, but they serve different buyers in meaningful ways — and this comparison will help you figure out which one belongs on your toilet.
| Feature | Kohler PureWash E815 (C3-325) | Kohler PureWash E820 (C3-455) |
|---|---|---|
| Image |  |
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| Dimensions (L x W x H) | 16-3/8″ x 15-11/16″ x 7-1/4″ | 20-5/8″ x 16-3/16″ x 5-1/8″ |
| Water Heating | Tank heater | Hybrid heater (continuous warm water) |
| Nozzle Cleaning | Auto self-cleaning (water rinse) | UV light auto sanitization |
| Spray Modes | Stream, Mist, Air Mist; 3D wash, Spa Spray, Boost Spray | Front & rear wash, oscillating, pulsating |
| Deodorizer | No | Yes (carbon filter) |
| Nightlight | No | Yes (LED bowl light) |
| Warranty | 3-year limited | 3-year limited |
| Buy Now |  |
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1. Kohler PureWash E815 (C3-325)
The PureWash E815 is the direct successor to the beloved Kohler C3-325, keeping everything that made that seat popular and refining it with a sleeker profile.
It fits most elongated toilets, connects to your existing water supply, and brings a full suite of electric bidet features — heated seat, warm water wash, and a warm-air dryer — into a clean, modern package controlled entirely by a handheld remote.
Features
- Three-sided rotating stainless steel wand with auto self-clean before and after each use
- Three spray modes: Stream, Mist, and Air Mist
- 3D wash feature oscillates the spray both back-and-forth and side-to-side
- Spa Spray mode activates a soothing air mist while automatically adjusting water temperature
- Boost Spray sets rear wash to maximum pressure instantly
- Child mode delivers a soft, gentle wash for younger users
- Handheld remote with two programmable user presets
- Heated seat with five adjustable temperature levels
- Quiet-Close lid, Grip-Tight bumpers, and Quick-Release for easy cleaning
- Power-save mode reduces energy use between sessions
- 3-year limited warranty
Pros
- Incredibly versatile spray system with more modes than most seats in this class
- 3D wash and Spa Spray set it apart from basic electric bidets
- Child mode makes it practical for family bathrooms
- Boost Spray delivers powerful cleaning when you need it most
- Two user presets mean everyone in the household gets their preferred settings instantly
Cons
- Tank-style heater means warm water supply is limited — long sessions may run cool
- No built-in deodorizer
- No LED nightlight for low-light bathroom trips
The E815 is the right call if you want maximum spray versatility and a feature set that rivals seats costing significantly more.
Its 3D wash, Spa Spray, and Boost modes give you a cleaning experience that goes well beyond a standard front-and-rear wash — and the Child mode is a genuine bonus if you have kids at home.
If you’re exploring the best bidets for existing toilets, the E815 belongs at the top of your shortlist.
Check its current price on Amazon
2. Kohler PureWash E820 (C3-455)
The PureWash E820 is the premium step-up from the C3-455, designed for buyers who want a more refined, hygiene-focused experience — and who want warm water that never runs out.
Where the E815 focuses on spray variety, the E820 doubles down on sanitation and comfort: a UV-sanitizing wand, automatic deodorization, an LED nightlight, and a hybrid heater that delivers continuously warm water for as long as you need it.
Features
- Hybrid heater delivers continuously heated water — no cold surprise mid-wash
- Stainless steel wand with UV light auto-sanitization after every use
- Front and rear wash modes with adjustable water temperature and pressure
- Oscillating and pulsating spray options for thorough, comfortable cleaning
- Automatic carbon filter deodorizer neutralizes odors during use
- LED nightlight illuminates the bowl for safe nighttime use
- Handheld remote with two programmable user presets
- Heated seat with adjustable temperature settings
- Warm-air drying system
- Quiet-Close lid, Quick-Release hinges for easy cleaning
- 3-year limited warranty
Pros
- Hybrid heater means unlimited warm water — ideal for extended use
- UV light wand sanitization is a significant hygiene upgrade over water-rinse-only cleaning
- Built-in carbon filter deodorizer keeps your bathroom smelling fresh automatically
- LED nightlight makes nighttime bathroom trips much safer and more comfortable
- Cleaner, more minimal aesthetic with remote-only operation
Cons
- No 3D wash, Spa Spray, or Boost Spray modes
- No Child mode
- Higher price point than the E815
The E820 is built for the buyer who wants their bidet seat to feel like an upgrade in every direction — not just cleaning performance, but bathroom hygiene overall.
The combination of UV wand sanitization, automatic deodorization, and a nightlight makes it the better choice for anyone who uses their bidet seat late at night or shares the bathroom with guests.
It’s also a strong pick if you tend to use longer wash cycles, since the hybrid heater keeps warm water flowing without any dropoff.
For a broader look at top-tier electric seats, our bidet toilet seat comparison chart puts the E820 in great context alongside competitors.
Check its current price on Amazon
Head-to-Head: Water Heating
This is the most important functional difference between these two seats.
The E815 uses a traditional tank-style heater that stores a reservoir of warm water ready to go the moment you press the wash button.
The water is immediately warm — which feels great — but that reservoir eventually runs out, and if your wash session goes long, you may encounter a temperature dip.
The E820 uses a hybrid heating system, combining a small reservoir with continuous on-demand heating.
That means you get the same instant warmth at the start, but the temperature stays consistent for as long as you’re washing.
Winner: E820. For most users the difference is minor, but for anyone who prefers longer wash sessions or lives in a colder climate, the hybrid heater is a meaningful upgrade.
Head-to-Head: Spray Versatility
The E815 wins this category convincingly.
Its three-sided rotating wand gives you Stream, Mist, and Air Mist modes, plus 3D wash (which oscillates the spray back-and-forth and side-to-side for more thorough coverage), Spa Spray mode (a soothing air mist with auto-adjusted temperature), and Boost Spray for maximum pressure cleaning.
The E820 keeps things simpler: front and rear wash, with oscillating and pulsating spray variations.
That’s still comfortable and effective — but it doesn’t match the spray depth of the E815.
Winner: E815. If customizable spray experience is your priority, the E815 is in a different league here.
Head-to-Head: Hygiene & Sanitation
Both seats clean their nozzles automatically before and after use — but the way they do it is very different.
The E815 rinses the wand with water.
That’s effective for everyday maintenance, but it doesn’t truly sanitize.
The E820 goes a step further with UV light technology, which actively kills bacteria and pathogens on the wand surface after each use — a meaningfully higher standard of hygiene.
Add in the E820’s carbon filter deodorizer, and it’s the clear winner if you care deeply about bathroom sanitation.
Winner: E820. UV sanitization and automatic deodorization make this a noticeably more hygienic seat.
Head-to-Head: Convenience Features
The E820 edges ahead here too, thanks to two extras the E815 simply doesn’t have.
The LED nightlight illuminates the bowl automatically, which is genuinely useful for nighttime trips to the bathroom — especially in households where people prefer not to turn on harsh overhead lights at 2am.
The Child mode on the E815 is a counterbalance here — families with young children will find that feature helpful in a way the E820 can’t match.
Winner: E820 for most users, with the caveat that families should weigh the E815’s Child mode.
Head-to-Head: Value
The E815 delivers a feature set that genuinely punches above its price class.
Its spray variety — 3D wash, Spa Spray, Boost Spray, Child mode — is impressive for what you pay, and the stainless steel wand ensures long-term durability.
The E820 costs more, and while its upgrades are real (UV sanitization, deodorizer, nightlight, hybrid heater), they come at a premium that not every buyer will need.
Winner: E815 on value. The E820 is worth the extra cost if those upgrades matter to you — but if you want the best bang-for-buck in the Kohler lineup, the E815 is hard to beat.
Verdict — Which One Should You Buy?
Both the Kohler PureWash E815 and E820 are excellent electric bidet seats.
They share the same Kohler build quality, the same 3-year warranty, and the same clean remote-controlled design — but they make very different tradeoffs.
Buy the Kohler PureWash E815 if:
- You want maximum spray variety — 3D wash, Spa Spray, Boost Spray, and more
- You have children at home and want Child mode
- You want the most feature-packed option at a lower price point
- Shorter wash sessions mean warm water supply isn’t a concern for you
Buy the Kohler PureWash E820 if:
- You want continuously warm water with no temperature dropoff
- UV wand sanitization and automatic deodorization matter to you
- You use the bathroom at night and want a bowl nightlight
- You share your bathroom with guests and want the cleaner, more premium seat
Frequently Asked Questions
Are the Kohler C3-325 and C3-455 still available?
The C3-325 and C3-455 have been updated and rebranded as the PureWash E815 and PureWash E820 respectively.
The new models carry over the same core technology with updated specs and names — so if you were shopping for the older versions, you’re in the right place.
Do both seats require electricity?
Yes.
Both the E815 and E820 are electric bidet seats and require a nearby GFCI-protected outlet (120V, 15A, 60Hz).
If your bathroom doesn’t already have an outlet near the toilet, you’ll need to have one installed before either seat will work.
If you’re not sure whether your setup is compatible, our guide on bidet toilets vs bidet seats covers installation requirements in more detail.
Can either seat fit a round toilet?
Both the E815 and E820 are designed for elongated toilets.
Kohler does make round-front versions of the E815 (model K-28118), so if you have a round toilet, you can still get the E815 experience — just check the right model number when ordering.
The E820 is elongated-only.
Which seat is better for seniors?
The E820 is the stronger choice for seniors, thanks to the LED nightlight (useful for low-light navigation), automatic deodorization (reduces bathroom odors without any effort), and the hybrid heater (consistently warm water without adjustment needed).
For more on choosing a bidet that works for older users, see our full guide on the best bidets for seniors.
Conclusion
The Kohler PureWash E815 and E820 represent two very capable points on the same product ladder.
The E815 gives you more spray options, a Child mode, and excellent value — it’s the pick for buyers who want the richest washing experience at a lower cost.
The E820 gives you better hygiene tech, unlimited warm water, a nightlight, and automatic deodorization — it’s the pick for buyers who want their bidet seat to elevate the entire feel of their bathroom.
Both are worth the upgrade from a basic bidet seat, and both carry Kohler’s reliable 3-year warranty to back them up.
If you’re still comparing options beyond the Kohler lineup, our bidet toilet seat comparison chart and reviews of the best bidets for home use are great next reads to help you land on the perfect seat.
