1. Introduction
This manual provides detailed instructions for the safe and efficient installation, operation, and maintenance of your Coway Bidetmega 400E Elongated Electronic Bidet Seat. Please read this manual thoroughly before installation and use, and keep it for future reference.
2. Safety Information
Always adhere to the following safety precautions to prevent injury or damage to the product.
- Ensure the operating voltage is 120V / 60Hz and use a grounded power outlet.
- Verify adequate tap water pressure between 14.5 PSI and 100 PSI.
- Do not attempt to repair or modify the unit yourself. Contact qualified service personnel.
- Keep the power cord away from heat sources and sharp edges.
- Avoid spraying water directly onto the electrical components.
3. Package Contents
Before beginning installation, ensure all components are present:
- Coway Bidetmega 400E Bidet Seat
- Bidet Hose
- Fixer Bracket
- 7/8" T-valve (Installation Adapter)
- Fixing Screws
- Fixing Nuts
- Fixing Sliders
- Fixing Washers
- Remote Control
- Remote Control Holder
- Remote Control Stand
- Remote Control Sticker
- Screws for Remote Holder
- Fixer Anchors
- Battery AAA (for remote)
- Remote Control Tape
You will also need a wrench and a screwdriver for installation.
4. Installation Guide
Follow these steps for proper installation of your bidet seat.
4.1 Pre-installation Checklist
- Ensure your toilet bowl type (Elongated or Round) matches the bidet seat. This model is for Elongated bowls.
- Confirm a grounded 120V / 60Hz power outlet is available near the toilet.
- Check for adequate water pressure (14.5 PSI ~ 100 PSI).

4.2 Water Source Connection
- Remove the existing toilet seat and lid.
- Turn off the water supply valve to the toilet and flush the toilet to drain the tank completely.
- Disconnect the water supply hose from the toilet's water supply pipe.
- Connect the provided 7/8" T-valve to the water supply valve.
- Connect the toilet's water supply hose to one outlet of the T-valve.
- Connect the bidet hose to the remaining outlet of the T-valve and to the bidet seat's water inlet. Ensure all connections are tight to prevent leaks.
- Reopen the water supply valve.
4.3 Product Installation
- Insert the fixing nuts into the toilet holes.
- Place the fixer bracket over the toilet holes, aligning it with the fixing nuts.
- Align the fixing sliders and fixing washers onto the bracket.
- Insert the fixing screws and tighten them clockwise until secure.
- Gently slide the bidet seat onto the bracket until you hear a click sound, indicating it is securely in place.
- Connect the power plug to a grounded electrical outlet.
5. Operating Instructions
Your Coway Bidetmega 400E is designed for intuitive operation using the wireless remote control.
5.1 Remote Control Overview
The remote control automatically pairs with your bidet. It features two displays (front and rear) and various buttons for different functions.

5.2 Key Functions
- Stop: Stops any active washing or drying cycle.
- Rear Wash: Activates the rear wash function.
- Front Wash: Activates the front wash function.
- Water Pressure: Adjusts the water spray intensity.
- Nozzle Position: Adjusts the nozzle's forward or backward position.
- Seat Temp: Adjusts the heated seat temperature.
- Water/Dry Temp: Adjusts the water and dryer air temperature.
- Dry: Activates the warm air dryer.
- Clean Bidet: Initiates the nozzle self-cleaning function.
- Mode: Cycles through different wash modes (Basic, Active Move, Soothing Wash, Care).
- Child Mode: Activates a gentle wash suitable for children (press both Basic and Active Move buttons).
5.3 Remote Control Mounting
You can set up your remote control in two ways:
- Wall-mount: Use the provided double-sided tape or screws to mount the holder on a clean wall.
- Remote Stand: Engage the stand and the holder, then tighten the two small screws provided.
6. Features
The Coway Bidetmega 400E offers a range of features for enhanced hygiene and comfort:
- i-wave Technology: Unique technology designed to fit every body for a comfortable cleaning experience.
- Dual Nozzle System: Separate nozzles for rear and front washing, ensuring hygienic cleaning.
- Heated Seat: Provides warmth and comfort, especially in colder environments.
- Warm Air Dryer: Reduces the need for toilet paper, offering a gentle and effective drying experience.
- Night Light: A soft blue LED light illuminates the toilet bowl, providing visibility in the dark.
- ECO Mode: An energy-saving function to reduce power consumption.
- Child Mode: A specialized gentle wash setting for children.
- Wireless Remote Control with Braille: Easy-to-use remote with tactile indicators for visually impaired users.
- IPX5 Waterproof: Provides protection against water jets from any direction.


7. Maintenance
Regular cleaning and maintenance will ensure the longevity and optimal performance of your bidet seat.
7.1 Cleaning the Nozzle
The bidet features a self-cleaning nozzle function. Additionally, you can manually clean the nozzle by detaching it if required.
7.2 Cleaning the Mesh Filter
The mesh filter inside the water inlet is detachable for cleaning with water. Regularly check and clean the filter to prevent blockages and maintain water flow.
7.3 General Cleaning
- To clean the bidet seat, gently slide the product off the bracket by pressing the release button and sliding it out.
- Use a soft, damp cloth and mild detergent. Avoid abrasive cleaners or solvents.
- The bidet is IPX5 waterproof, allowing for safe cleaning with water, but avoid direct high-pressure spraying on electrical components.
8. Troubleshooting
If you encounter any issues, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No water spray | Water supply valve closed; clogged mesh filter | Open water supply valve; clean mesh filter |
| Weak water pressure | Low household water pressure; clogged mesh filter | Check household water pressure; clean mesh filter |
| Heated seat not working | Power not connected; seat temperature setting too low | Ensure power is connected; adjust seat temperature on remote |
| Remote control not responding | Batteries drained; remote not paired | Replace batteries; ensure remote is within range and paired |
If the problem persists, please contact Coway customer support.
9. Specifications
- Model: Bidetmega 400E
- Color: White
- Product Dimensions: 23.25"D x 8.25"W x 19"H
- Material: Stainless Steel (nozzle), Plastic (seat)
- Item Weight: 17.41 pounds (7.91 Kilograms)
- Installation Type: Floor Mounted
- Shape: Elongated
- Operating Voltage/Hertz: 110V / 60Hz
- Operating Tapwater Pressure: 14.5 PSI ~ 100 PSI
- UPC: 826439000318
- ASIN: B082LZC4N4
10. Warranty and Support
Warranty Description: 1-Year Manufacturer’s Limited Warranty.
For customer support, troubleshooting assistance, or warranty claims, please refer to the contact information provided in your product packaging or visit the official Coway website.





