1. Introduction and Overview
Thank you for choosing the Hembisen Carbon Monoxide (CO) Detector. This device is designed to monitor carbon monoxide levels in your environment and alert you to potentially dangerous concentrations, helping to ensure the safety of your home and family. Carbon monoxide is a colorless, odorless, and tasteless gas, making a reliable detector an essential safety measure.


2. Safety Information
Please read all safety instructions carefully before using this product. Failure to follow these instructions may result in product malfunction, property damage, or serious injury.
- This carbon monoxide detector is designed to detect naturally occurring carbon monoxide in the environment. It is not intended to detect other gases or smoke.
- The detector has an alarm threshold and will only trigger when the concentration of carbon monoxide reaches a specific alarm value.
- Do not install the detector in very dirty, dusty, or greasy places such as kitchens, garages, or industrial rooms. Oil, dust, or household chemicals can contaminate the sensor, affecting its proper function.
- Regularly check the product to ensure the green 'Power' light is continuously illuminated, indicating it is functioning correctly.
- Ensure the power source and outlet are functioning properly.
3. Product Features
- Accurate & Easy to Read: Equipped with a new imported electrochemical sensor for high reliability and responsiveness, minimizing false alarms.
- AC Power Plug-in Design: Eliminates complex installation. Simply plug into a standard AC outlet for immediate use.
- Breakthrough Heat Dissipation: Constructed with ABS advanced material and an optimized heat dissipation structure for continuous daily use without overheating.
- Digital Display: Provides real-time monitoring of carbon monoxide gas levels in parts per million (PPM), offering clear and easy-to-understand readings.
- Loud 85dB Warning: When carbon monoxide concentration reaches the default alarm value, the detector emits a loud 85dB alarm, ensuring prompt awareness for safety.

4. Specifications
| Specification | Detail |
|---|---|
| Brand | Hembisen |
| Model Number | WA996 |
| Power Source | Plug-and-play (AC Power) |
| Product Dimensions | 1.5"D x 2.76"W x 4.33"H |
| Item Weight | 4.5 Ounces |
| Alarm Type | Audible (85dB) |
| Sensor Type | Electrochemical |
| Alarm Concentration | 150 PPM (as per product image) |
| UPC | 632368770563 |

5. Setup
The Hembisen Carbon Monoxide Detector is designed for simple, plug-and-play installation.
- Unpack the detector from its packaging.
- Select an appropriate location for installation (refer to Section 9: Placement Guidelines).
- Plug the detector directly into a standard AC wall outlet.
- The device will undergo a short warm-up period. Once powered, the green 'Power' indicator light should illuminate.
- Perform a self-test as described in Section 6: Operating Instructions to ensure proper functionality.
This video demonstrates the simple plug-in setup of the Hembisen Carbon Monoxide Detector.
6. Operating Instructions
Once plugged in, the detector continuously monitors carbon monoxide levels.
- Digital Display: The LED screen displays the current carbon monoxide concentration in PPM (parts per million). In normal conditions, it may show '0000' or a low background reading.
- Power Indicator (Green LED): A continuously lit green light indicates the device is powered on and operating normally.
- Fault Indicator (Yellow LED): A lit yellow light indicates a fault or malfunction with the device. Refer to the Troubleshooting section.
- Alarm Indicator (Red LED): A flashing red light, accompanied by an audible alarm, indicates detected carbon monoxide levels are at or above the alarm threshold.
- Self-Test Button: Press and hold the 'SELF-TEST' button to manually test the alarm and display functionality. The device will typically cycle through its indicators and emit a test alarm sound.
7. Alarm Indications
The Hembisen Carbon Monoxide Detector is designed to alert you to dangerous CO levels with both visual and audible signals.
- Audible Alarm: A loud 85dB siren will sound when CO levels reach the alarm threshold (e.g., 150 PPM).
- Visual Alarm: The red 'Alarm' LED will flash, and the digital display will show the detected CO concentration.
If the alarm sounds:
- Immediately move to fresh air outdoors or open all doors and windows to ventilate the area.
- Do a head count to check that all persons are accounted for.
- Do not re-enter the premises until the alarm has stopped and the area has been thoroughly ventilated.
- Call emergency services or a qualified technician to investigate the source of the carbon monoxide.
8. Maintenance
Proper maintenance ensures the longevity and accuracy of your CO detector.
- Regular Cleaning: Clean the detector with a soft-bristled brush or a vacuum cleaner on a weekly basis to prevent dust and debris from accumulating on the sensor.
- Daily Check: Visually inspect the detector daily to ensure the green 'Power' light is constantly on.
- Monthly Self-Test: Press the 'SELF-TEST' button monthly to verify the alarm and display are working correctly.
- Avoid Obstructions: Ensure the air inlet and outlet vents are not blocked by furniture, curtains, or other objects.
9. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power/Display off | Power outage, faulty outlet, loose connection | Check power supply, try a different outlet, ensure secure connection. |
| Yellow 'Fault' light on | Internal malfunction, sensor issue | Unplug and re-plug the device. If the fault persists, contact customer support. |
| Alarm sounds without visible CO source | False alarm, low-level CO presence, detector near combustion source | Ventilate the area. If alarm persists, treat as a real alarm and evacuate. Ensure detector is not too close to appliances that produce CO. |
| Inaccurate readings (e.g., high PPM without CO source) | Dust/debris on sensor, chemical interference | Clean the detector as per maintenance instructions. Relocate if near strong chemical fumes. |
10. Placement Guidelines
Optimal placement of your Hembisen Carbon Monoxide Detector is crucial for effective monitoring.
- Install at least one detector on each level of your home, especially near sleeping areas and living spaces.
- For best results, place detectors at outlet height, as carbon monoxide mixes with air.
- Consider placing a detector in rooms with fuel-burning appliances (e.g., furnace, water heater, fireplace).
- Avoid placing detectors directly above or next to fuel-burning appliances, as this can lead to false alarms during normal operation.
- Do not place in direct sunlight, near windows or doors, or in areas with high humidity or extreme temperatures.
- Keep the detector away from vents, fans, or other air currents that might prevent CO from reaching the sensor.




11. Warranty and Support
Specific warranty details are not provided in the product information. For warranty claims, technical support, or further inquiries, please contact Hembisen customer service directly through the retailer where the product was purchased or visit the official Hembisen website.