Sejoy C12
Sejoy Water Flosser C12 User Manual
Model: C12 | Brand: Sejoy
Product Overview
The Sejoy Water Flosser C12 is a portable, cordless electric dental flosser designed for daily oral care. It features a 350ML detachable water tank, 5 professional cleaning modes, and comes with 9 interchangeable jet tips to meet various oral hygiene needs. Its powerful battery ensures long-lasting use, making it ideal for home and travel.

Image: Sejoy Water Flosser C12 with its packaging, various jet tips, and USB charging cable.
Safety Information
Important Safety Precautions:
- Always keep the water flosser away from water when charging.
- Do not use the water flosser if you have any medical conditions, including but not limited to, epilepsy, heart conditions, or are pregnant.
- Always supervise children when using the water flosser.
- Do not use the water flosser with damaged or worn-out nozzles.
- If you experience any discomfort or pain while using the water flosser, stop using it immediately and consult a dental professional.
Setup Guide
1. Charging the Device
The Sejoy Water Flosser is equipped with a 2000mAh powerful lithium battery. Before first use, fully charge the device. A full charge takes approximately 4 hours and provides up to 30 days of continuous use.
- Connect the provided USB cable to the charging port on the device.
- Plug the other end of the USB cable into a compatible USB power source (e.g., power bank, computer, phone charger, car charger).
- The indicator lights will show charging status. Once fully charged, disconnect the cable.

Image: Illustration of the Sejoy Water Flosser's USB charging port and battery life indication.
2. Attaching a Nozzle
The water flosser comes with 9 different nozzles for various needs, including standard, tongue cleaner, periodontal, and orthodontic tips. To attach a nozzle:
- Select the desired nozzle.
- Insert the nozzle into the opening at the top of the flosser until it clicks into place.
- To remove, press the knob/button on the side of the flosser and pull the nozzle out.

Image: Visual guide to the different types of nozzles included: Tongue Cleaner, Periodontal Tip, Standard Jet Tip, and Orthodontic Tip.
3. Filling the Water Tank
The 350ML detachable water tank provides sufficient capacity for a thorough cleaning session.
- Detach the water tank from the main unit by pulling it downwards.
- Open the water tank cap.
- Fill the tank with warm water.
- Close the cap securely and reattach the tank to the main unit, ensuring it clicks into place.

Image: Steps showing how to detach, fill, and reattach the 350ML water tank for easy use and cleaning.
Operating Instructions
1. Selecting a Cleaning Mode
The Sejoy Water Flosser offers 5 professional cleaning modes:
- Soft (60psi): Ideal for children or first-time users.
- Normal (90psi): For effective daily cleaning.
- Strong (110psi): For deep cleaning of teeth and braces.
- Pulse (60-110psi): Provides a massage for gums.
- DIY Mode (50-120psi): Allows for 10 freely adjustable speeds to customize water pressure according to your dental needs.
Press the mode button to cycle through the available modes. For DIY mode, long press the mode button to enter, then short press to adjust pressure.

Image: Visual representation of the 5 water pressure modes and their recommended uses.

Image: Instructions on how to enter and adjust settings within the DIY mode.
2. Using the Water Flosser
- After filling the tank and selecting your mode, place the tip in your mouth.
- Close your lips around the nozzle to form a tight seal and lean over a sink.
- Turn on the water flosser using the power button.
- Guide the tip along your gum line and teeth, pausing briefly on each tooth. The 360° rotatable nozzle allows easy access to all areas of the mouth.
- Continue for approximately 2 minutes or until all areas are cleaned.
Important: Make sure you have pointed it into your mouth before you turn it on. Do not take the water flosser out of your mouth while it is working. The mouth can be slightly closed during the flushing process.

Image: Step-by-step visual guide on how to add water, attach tips, choose pressure, position in mouth, and turn on for cleaning.

Image: Close-up view of the 360-degree rotatable nozzle and the button to unlock/release the tip.
Maintenance and Cleaning
Proper maintenance ensures the longevity and hygiene of your Sejoy Water Flosser.
Daily Cleaning
- After each use, remove the nozzle and rinse it under clean water.
- Empty any remaining water from the tank.
- Clean the water tank and any other parts that came into contact with water. The detachable design makes this easy.
- Wipe the main unit with a soft, damp cloth.
- Store the device in a dry place.

Image: The Sejoy Water Flosser submerged in water, demonstrating its IPX7 waterproof rating. A note reminds users to ensure the base cover is closed tightly before use.
Nozzle Replacement
For optimal hygiene and performance, it is recommended to replace the nozzle every 3 months.
Troubleshooting
| Problem | Possible Cause / Solution |
|---|---|
| Device does not turn on or spray water on first use. | The device may need priming. Turn it on, hold it upside down, and wait until it starts to spray. This primes the pump for initial use. |
| Water leakage. | Ensure the water tank is securely attached and the base cover is tightly closed. Check for any cracks or damage to the tank or seals. |
| Reduced water pressure. | Check if the water tank is sufficiently filled. Ensure the nozzle is not clogged. Clean the nozzle and internal components thoroughly. |
| Mold or residue buildup inside the unit. | Regularly clean the detachable water tank and rinse all parts that come into contact with water. For deeper cleaning, run a solution of water and white vinegar through the unit. Ensure the unit is completely dry before storage. |
Product Specifications
- Model Number: C12
- Brand: Sejoy
- Water Tank Capacity: 350ML
- Cleaning Modes: 5 (Soft, Normal, Strong, Pulse, DIY)
- Pressure Range: 50-120psi (DIY Mode)
- Nozzles Included: 9 (Standard, Tongue Cleaner, Periodontal, Orthodontic)
- Battery: 2000mAh Lithium Battery
- Charging Time: Approx. 4 hours
- Usage Time: Up to 30 days (continuous use)
- Waterproof Rating: IPX7
- Power Source: Battery Powered
- Product Benefits: Removes Plaque and Improves Gum Health
- Package Dimensions: 10.43 x 4.02 x 3.9 inches
- Item Weight: 1.1 Pounds
Warranty and Support
Specific warranty information for the Sejoy Water Flosser C12 is not provided within this manual. For details regarding warranty coverage, technical support, or replacement parts, please refer to the official Sejoy website or contact their customer service directly.
Manufacturer: Sejoy
Date First Available: October 10, 2024
For further assistance, please visit the Sejoy Store on Amazon.
Ask a question about this manual
Ask about setup, troubleshooting, compatibility, parts, safety, or missing instructions. Manuals+ will review the question and use this page’s manual context to help answer it.