1. Introduction
Thank you for choosing the SUNSUN ARK Series Aquarium Heater. This high-power, explosion-proof heating rod is designed to maintain a stable and optimal temperature in your fish tank, ensuring the well-being of your aquatic inhabitants. Featuring advanced PTC heating technology, digital temperature display, and external temperature control, this heater offers convenience, safety, and efficiency for both freshwater and saltwater aquariums.
2. Safety Information
- Always unplug the heater from the power outlet before performing any maintenance, water changes, or handling the heater.
- Ensure the heater is fully submerged in water before plugging it in. Operating the heater out of water can cause damage and pose a fire hazard.
- The heater is designed to be explosion-proof, but proper installation and usage are crucial.
- Keep the power cord and controller away from water splashes.
- Do not use the heater if the power cord or the unit itself is damaged.
- This appliance is suitable for both freshwater and saltwater environments.
- The heater features dual temperature sensing probes for accurate and reliable temperature monitoring.
3. Product Features
- External Temperature Control: Conveniently adjust temperature settings from outside the fish tank.
- Digital Display: Clear 3-digit digital screen displays current water temperature and real-time heating power.
- Dual Temperature Sensing Probes: Enhances accuracy and provides redundancy, preventing non-heating or overheating due to single probe failure.
- PTC Heating Technology: Efficient and stable heating.
- Explosion-Proof Design: Enhanced safety for aquarium use.
- Corrosion Resistance: Suitable for both freshwater and saltwater aquariums.
- Overheat Protection: Automatically displays 'E-1' and stops heating if water temperature exceeds set limits.
- Dry-Burn Protection: Automatically displays 'E-4' and cuts power if the heater is not submerged in water.
4. Setup
- Unpack: Carefully remove the heater and all components from the packaging. Inspect for any damage.
- Placement: Position the heating rod fully submerged in your fish tank. Ensure it is placed in an area with good water circulation for even heat distribution. Use the included suction cups to secure it to the tank wall.
- Controller Placement: Mount the external controller in a dry, easily accessible location outside the fish tank. Ensure the power cord is routed safely and not pinched.
- Power Connection: Plug the heater's power cord into a suitable power outlet. The digital display will light up.

5. Operating Instructions
- Power On: Once plugged in, the digital display will show the current water temperature.
- Set Temperature: Use the temperature adjustment button on the external controller. Each tap will increase the set temperature by 0.5°C. The temperature setting range is 20-35°C. The display will show the set temperature briefly, then revert to the current water temperature.
- Real-time Power Display: The display will also show the real-time heating power (in Watts) as the heater operates.
- Heating Indicator: A red indicator light typically signifies that the heater is actively heating. A blue light may indicate standby or normal operation.

6. Maintenance
- Regular Cleaning: Periodically clean the heating rod to remove algae or mineral buildup. Always unplug the heater and allow it to cool completely before cleaning. Use a soft cloth or brush and aquarium-safe cleaning solutions if necessary.
- Water Changes: Before performing water changes, always unplug the heater to prevent dry-burning. Wait at least 5 minutes after unplugging before removing the heater from the water or lowering the water level below the heater's minimum submersion line.
- Inspect Cords: Regularly check the power cord and controller for any signs of wear, cuts, or damage.
7. Troubleshooting
| Error Code / Symptom | Possible Cause | Solution |
|---|---|---|
| E-1 displayed (Overheat Protection) | Water temperature exceeds the set temperature or safe operating limit. | Check the set temperature. Ensure proper water circulation. If the ambient temperature is too high, consider cooling the room or tank. The heater will resume normal operation once the temperature drops. |
| E-4 displayed (Dry-Burn Protection) | Heater is not fully submerged in water or water level is too low. | Immediately unplug the heater. Check the water level and ensure the heater is completely submerged. Wait for the heater to cool down before plugging it back in. |
| Heater not heating | Power outage, faulty outlet, heater unplugged, or set temperature is below current water temperature. | Check power supply. Ensure the heater is plugged in. Verify the set temperature is higher than the current water temperature. |
| Inconsistent temperature readings | Poor water circulation around the heater or faulty sensor. | Ensure adequate water flow around the heater. Clean any debris from the heater surface. If issues persist, contact support. |
8. Specifications

General Specifications:
- Brand: SUNSUN
- Type: Fish Tank Heater
- Heating Element: PTC (Positive Temperature Coefficient)
- Temperature Control Range: 20-35°C (68-95°F)
- Controller Mode: Relay
- Alarm Mode: LED light flashes
- Voltage: 220-240V 50/60Hz
- Smart Device: No
- Battery Included: No
Model-Specific Specifications (Refer to Figure 3 for full details):
- Power Options: 50W, 100W, 300W, 500W, 800W, 1000W
- Sizes (approx.):
- 50W, 100W, 300W models: 20.5 x 6.5 x 2.5 cm
- 500W, 800W, 1000W models: 29.5 x 7.5 x 3 cm
- Applicable Water Volume: Ranges from 20-30L (50W) up to 700-900L (1000W)
- Applicable Fish Tank Length: Ranges from 30-40cm (50W) up to 160-200cm (1000W)
- Power Cable Length: 1.6m for lower wattage models, 2.2m for higher wattage models.
9. User Tips
- Choose Correct Wattage: Select a heater wattage appropriate for your tank size to ensure efficient and stable temperature control.
- Monitor Temperature: While the heater has a built-in thermostat, it's always a good practice to use an independent aquarium thermometer to verify the water temperature.
- Avoid Direct Sunlight: Place your aquarium away from direct sunlight or other heat sources that could cause temperature fluctuations.
- Acclimation: When introducing new fish or after major water changes, ensure the water temperature is stable before adding livestock.
10. Warranty and Support
For warranty information, technical support, or service inquiries, please contact the seller or manufacturer directly. Keep your purchase receipt as proof of purchase.





