The Eheim Thermopreset Heater is a compact, easy-to-use aquarium heater designed to maintain a constant 25°C without the need for manual temperature adjustment. Its electronically controlled heating system provides accurate temperature regulation and even heat distribution, making it an excellent plug-and-play option for tropical freshwater and marine aquariums.
Unlike the adjustable Eheim Thermocontrol range, the Thermopreset is factory set to 25°C, making it especially convenient for aquariums where a standard tropical temperature is required. A protective plastic guard surrounds the heater for additional durability, while an LED indicator shows when the heater is actively operating. Eheim also includes automatic dry-running protection for added safety.
Available Sizes & Specifications
| Model |
Eheim Recommended Aquarium Size |
Heater Length |
Diameter |
| 50W |
25–60L |
168.5mm |
28.2mm |
| 100W |
100–150L |
183.5mm |
28.2mm |
| 150W |
200–300L |
223.5mm |
28.2mm |
| 200W |
300–400L |
253.5mm |
28.2mm |
These are Eheim's official heater ratings and dimensions for the Thermopreset range.
Key Features
✔ Factory Preset to 25°C – No manual temperature adjustment required
✔ Electronic Temperature Control – Maintains a stable and accurate aquarium temperature
✔ Four Wattages Available – 50W, 100W, 150W and 200W
✔ Compact Design – Slim 28.2mm diameter keeps the heater unobtrusive inside the aquarium
✔ Protective Plastic Guard – Provides additional mechanical protection around the heater
✔ Even Heat Distribution – Efficient heating element distributes warmth throughout the aquarium
✔ LED Heating Indicator – Shows when the heater is actively heating
✔ Dry-Run Protection – Helps protect the heater if it is accidentally operated outside the water
✔ Fully Submersible – Designed for installation inside the aquarium
✔ Secure Suction Cup Mounting – Keeps the heater securely positioned
✔ Freshwater & Marine Suitable – Suitable for tropical freshwater and saltwater aquariums
✔ 3-Year Eheim Manufacturer Warranty
Thermopreset vs Thermocontrol
The Thermopreset is designed for aquarists wanting a simple, fixed-temperature heater.
✔ Thermopreset: Factory set to 25°C – plug in and let the heater automatically maintain the temperature
✔ Thermocontrol: Adjustable temperature – better suited when you need to select a specific temperature for your fish
Perfect For
✔ Tropical freshwater aquariums
✔ Community fish tanks
✔ Planted aquariums
✔ Cichlid aquariums
✔ Marine and saltwater aquariums
✔ Aquariums maintained around 25°C
✔ Aquarists wanting simple plug-and-play heating
✔ Setups where adjustable temperature control isn't required
Important Heater Sizing Information
The aquarium sizes listed are Eheim's official recommendations. Heater requirements can also depend on room temperature, desired aquarium temperature, aquarium dimensions and whether the tank is covered or open-top.
