Why You’ll Love It
Designed with intelligent inverter technology, the dual-core heater keeps the water at a constant temperature through the built-in chip with 0.1°F accuracy. It has a built-in dual temperature control system for over-temperature protection, low-temp alarms, dual °F/°C control, and automatic power-off.
Key Features
Precise Temperature Regulation
Leveraging intelligent inverter technology, the hygger 066 Aquarium Dual-Core Heater maintains a stable water temperature with a built-in chip that achieves accuracy to 0.1°F. It is equipped with 3 smart protectors and a dual temperature control system for both Fahrenheit and Celsius. The adjustable temperature range spans from 63°F to 94°F (17°C to 34°C). To switch between temperature units, simply long-press the controller’s set button for 2–3 seconds.

Overheating Prevention
The dual-core heater is designed to display an error code “HH” when the water temperature surpasses 93°F; at this point, it will automatically cease heating to prevent overheating.
Low-Temperature Guard
If the tank’s water temperature drops below 59°F, the variable-frequency heater will display “LL” and continue to heat the water to ensure the aquatic environment remains a stable temperature.
Dry Run Safety Feature
If the HG066 heater is not submerged in water, the display will flash “Auto shut off,” and the power will be automatically cut off to prevent dry running and potential damage.

Intuitive Digital LED Display
The dual-core heater is equipped with a distinctive smart LED screen that is fully waterproof, providing clear visibility of the current water temperature, set temperature, operating power, error codes, and operational status.
External Temperature Control
The external controller features intuitive indicators: a red light signifies that the heater is actively warming the water, while a white light indicates that the heater is off, maintaining the set temperature.
Safety and Durability
Constructed with explosion-proof quartz glass and thermally stable nickel-chromium wire, the hygger variable-frequency heater transfers heat to the water quickly and steadily. Its shell cover is made from heat-resistant ABS material, ensuring the safety of aquatic pets.
Convenient Power-Off Memory
In a power outage, the dual-core heater retains its last settings, automatically resuming operation according to these preferences once power is restored.
Usage Tips
How to position the hygger 066 dual-core heater within your aquarium?

Note: Always unplug the heater before removing it from the tank. Allow the heater to cool down for 10–20 minutes to avoid burns or injuries while cleaning the fish tank or changing the water.
Specification

Package:
1 x Heater with controller
4 x Suction cups
2 x Sucker holders
1 x User manual















Overheating and low temperature protection is nice for my fish. And the memory function is my favor. Because I don’t need to reset it in the case of power outage.