1. Introduction
Thank you for choosing the Weytoll FJ3551A Wireless Weather Station. This device provides accurate indoor and outdoor temperature and humidity readings, weather forecasts, an alarm clock with snooze function, and a clear, colorful LCD touch screen. This manual will guide you through the setup, operation, and maintenance of your new weather station.
2. Package Contents
- 1 x Wireless Weather Station (Main Unit)
- 1 x Wireless Outdoor Sensor
- 1 x USB Cable
- 1 x User Manual
3. Product Overview
Familiarize yourself with the main unit and its components:

Front Panel Controls and Display Elements:
- A1: 'Snooze/Backlight' button: Activates snooze during alarm, adjusts backlight intensity.
- A2: Alarm clock icon: Indicates alarm is set.
- A3: Weather forecast icons: Displays predicted weather conditions (sunny, cloudy, overcast, rain).
- A4: Date: Shows the current date.
- A5: Time: Displays the current time.
- A6: Indoor Temperature: Current temperature inside.
- A7: Comfort expression: Icon indicating indoor comfort level (DRY, COM, WET).
- A8: Indoor Humidity: Current humidity inside.
- A9: Outdoor sensor channel indicator: Shows which outdoor sensor channel is active.
- A10: Outdoor Temperature: Current temperature from the outdoor sensor.
- A11: Outdoor Humidity: Current humidity from the outdoor sensor.
- A12: '°C/°F' switch: Toggles temperature unit between Celsius and Fahrenheit.
- A13: Sensor channel/up button: Cycles through outdoor sensor channels or increases values during setting.
- A14: Menu/down button: Accesses settings menu or decreases values during setting.
Rear Panel and Power:
- AA battery x2: Battery compartment for backup power (batteries not included).
- DC 5V USB power supply: Main power input for the unit.



4. Specifications
| Feature | Specification |
|---|---|
| Material | ABS |
| Color | Black |
| Display Type | DIGITAL, Colorful LCD Touch Screen |
| Time Mode | 12hr / 24hr |
| Calendar | Up to 2099 |
| Alarm Function | Daily Alarm with 5-minute Snooze |
| Indoor Humidity Range | 20%RH ~ 95%RH |
| Outdoor Humidity Range | 20%RH ~ 95%RH |
| Indoor Temperature Range | 0℃ (32℉) ~ 50℃ (122℉) |
| Outdoor Temperature Range | -40℃ (-40℉) ~ 70℃ (158℉) |
| Temperature Unit | ℃ / ℉ switchable |
| Indoor Comfort Levels | 3 levels (DRY, COM, WET) |
| Wireless Outdoor Sensors | Supports up to 3 (1 included) |
| Outdoor Sensor Waterproof Rating | IPX4 |
| Data Transmission Range | 60m (in open area) |
| Installation Options | Wall mounted or standing station |
| Power Supply | 2 x LR6 AA batteries (not included) / USB Charging (DC 5V) |
| Item Size (Main Unit) | 161 x 115 x 32 mm / 6.34 x 4.53 x 1.26 inches |
| Item Weight (Main Unit) | 214 g / 7.55 oz |
| Package Dimensions | 16 cm (Length) x 12 cm (Width) x 6 cm (Height) |
| Package Weight | 0.345 kg |


5. Setup
5.1 Powering the Main Unit
- USB Power: Connect the provided USB cable to the DC 5V USB power supply port on the back of the main unit (refer to Figure 3.1). Plug the other end into a compatible USB power adapter (not included) or a USB port on a device like a power bank or laptop. This is the primary power source.
- Battery Backup: For backup power, open the battery compartment on the back of the main unit and insert 2 x LR6 AA batteries (not included), ensuring correct polarity. The unit can operate on batteries alone, but the backlight functionality may be limited to conserve power.

5.2 Powering the Wireless Outdoor Sensor
- Open the battery compartment on the back of the wireless outdoor sensor.
- Insert 2 x AA batteries (not included), observing correct polarity.
- Close the battery compartment securely.
5.3 Initial Pairing and Placement
- Place the main unit and the outdoor sensor close to each other during initial setup.
- Once both units are powered, the main unit will automatically search for the outdoor sensor. The outdoor temperature and humidity should appear on the main unit's display.
- Outdoor Sensor Placement: The outdoor sensor is IPX4 waterproof, meaning it is resistant to splashing water. For best results and accurate readings, place the sensor in a shaded area, away from direct sunlight and heavy rain. Ensure it is within 60 meters (197 feet) of the main unit in an open area. Avoid placing it near large metal objects or other electronic devices that might cause interference. The sensor can be wall-mounted or placed on a stand.

5.4 Mounting the Main Unit
The main unit can be placed on a flat surface using its integrated stand or wall-mounted using the hanging hole on its back.
6. Operation
6.1 Setting Time and Date
- Press and hold the 'Menu/down' button (A14) to enter time setting mode.
- Use the 'Sensor channel/up' button (A13) and 'Menu/down' button (A14) to adjust the values (e.g., hour, minute, year, month, day).
- Press the 'Menu/down' button (A14) again to confirm each setting and move to the next.
- The calendar supports dates up to 2099.
6.2 Setting Alarm and Snooze
- Press the 'Menu/down' button (A14) once to display the alarm time.
- Press and hold the 'Menu/down' button (A14) to enter alarm setting mode.
- Adjust the alarm hour and minute using the 'Sensor channel/up' button (A13) and 'Menu/down' button (A14).
- Press 'Menu/down' button (A14) to confirm.
- When the alarm sounds, press the 'Snooze/Backlight' button (A1) to activate the 5-minute snooze function. To turn off the alarm, press any other button.
6.3 Temperature Unit Selection (°C/°F)
Press the '°C/°F' switch button (A12) on the front panel to toggle between Celsius and Fahrenheit display for both indoor and outdoor temperatures.
6.4 Backlight Adjustment
Press the 'Snooze/Backlight' button (A1) repeatedly to cycle through 4 backlight levels: High, Medium, Low, and Off. Note that backlight intensity may be limited when operating on battery power only.
6.5 Weather Forecast
The weather station provides a personalized forecast based on changes in temperature, humidity, and barometric pressure. The forecast is displayed using vivid icons (A3) for sunny, cloudy, overcast, and rain conditions (refer to Figure 3.3).
6.6 Indoor Comfort Level
The main unit displays a comfort expression icon (A7) based on indoor temperature and humidity. There are three levels: DRY, COM (comfortable), and WET (refer to Figure 3.4). If the surrounding temperature is higher than 25°C or lower than 20°C, the comfort expression will not be displayed.
6.7 Max/Min Temperature and Humidity Records
The weather station automatically records the maximum and minimum indoor/outdoor temperature and humidity values. Press the 'MEM' button (part of A13/A14 button cluster) to view these records. Press again to clear them.
6.8 Multiple Outdoor Sensors (Optional)
The weather station supports up to 3 wireless outdoor sensors. If you have additional sensors, press the 'CH' button (part of A13/A14 button cluster) to cycle through the channels (CH1, CH2, CH3) and view readings from different sensors.
7. Maintenance
7.1 Cleaning
Wipe the main unit and outdoor sensor with a soft, damp cloth. Do not use abrasive cleaners or solvents, as they may damage the display or casing.
7.2 Battery Replacement
When the low battery indicator appears on the display, replace the batteries in both the main unit (if using backup) and the outdoor sensor promptly to ensure continuous operation and accurate readings.
7.3 Outdoor Sensor Care
Although the outdoor sensor is IPX4 waterproof, prolonged exposure to extreme weather conditions (e.g., heavy rain, direct intense sunlight, snow) may affect its lifespan and accuracy. Position it in a sheltered location if possible.
8. Troubleshooting
- No display on main unit:
- Ensure the USB cable is securely connected and receiving power.
- If using battery backup, check if the AA batteries are inserted correctly and are not depleted. - No outdoor temperature/humidity reading:
- Check the batteries in the outdoor sensor and replace if necessary.
- Ensure the outdoor sensor is within the 60-meter transmission range of the main unit and there are no major obstructions.
- Try repositioning both units to minimize interference. - Inaccurate readings:
- Ensure the outdoor sensor is not in direct sunlight or exposed to heat sources, which can skew temperature readings.
- Verify that both units are placed in well-ventilated areas. - Low battery indicator:
- Replace the batteries in the respective unit (main unit or outdoor sensor) as soon as possible.
9. User Tips
- Multiple Sensors: The weather station is designed to support up to three outdoor sensors. If you wish to monitor different locations, you can purchase additional compatible sensors and easily switch between their readings using the 'CH' button.
- Optimal Backlight: For continuous, bright backlight, always use the USB power supply. Battery power is best for temporary use or as a backup.
10. Warranty and Support
For any questions, technical support, or warranty claims, please contact the seller or manufacturer directly. Refer to your purchase documentation for specific contact information.