Coway
Coway Bidetmega 400S
Coway retired the original Bidetmega 400 and replaced it in 2025 with this 400S — same design-award-winning minimalist look, now with instant tankless heating and 'Triple Hygiene Care' (anti-stick WaterShield bowl mist, auto-cleaning stainless nozzle, and UV nozzle light). Its signature i-wave system runs automated multi-stage wash courses that vary pressure, temperature, and motion. Lists at $599 direct but typically sells around $450 on Amazon.
Specifications
Features
Pros
- ✓i-wave course washes are the standout: one button runs a 3-stage cycle that steps through pressure, temperature, and nozzle motion — closest thing to 'set and forget' in this price class
- ✓New-for-400S instant heating ends the original 400's warm-water limits, and a dedicated child mode makes it a favorite for family bathrooms
- ✓WaterShield mist pre-wets the bowl before you go — the same anti-stick trick as Toto's premist, which the Alpha JX only recently copied
- ✓UV light plus auto-rinse keeps the stainless nozzle sanitized between uses, a hygiene stack usually found on $700+ seats
- ✓Two user-preset buttons sit right on the remote (User 1 / User 2), so couples aren't re-dialing settings every visit
- ✓The flat, sculpted lid won a 2024 PIN UP Design Award — repeatedly called the best-looking seat this side of a Toto S550e
- ✓A Gadgeteer reviewer reported zero complaints after 6 months and noted it matches competitors' features 'for $100 less'
- ✓Home Depot reviewers describe the default spray as 'just right' — firm but never harsh, ideal for sensitive skin and first-timers
Cons
- ✗The warm-air dryer is the most-cited weakness — reviewers say it's underpowered and most still finish with a pat of paper
- ✗The power cord is notably short; multiple owners had to buy an extension cord to reach their outlet
- ✗No deodorizer, which the similarly-priced Toto C5 includes
- ✗Turbo mode aside, peak pressure is tuned gentle — spray-strength chasers coming from a Bio Bidet vortex wash will be underwhelmed
- ✗Only a 1-year warranty against Alpha's 3 years and the Discovery DLS's 5 — thin coverage for a $450 electronics purchase
- ✗The seat body is bulkier front-to-back than it photographs, and some owners mention losing sitting room
- ✗The 400S launched in 2025, so there's no long-term reliability record yet — and original 400 owners report its parts are drying up post-discontinuation
- ✗Coway's direct price is $599 while Amazon sells it near $450; the retailer spread makes it easy to overpay
Compare the Coway Bidetmega 400S
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