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Is the 150 W Type 3666 inside EHEIM's published capacity range for a 65-gallon freshwater aquarium?
Yes, the operating manual lists Type 3666 for about 200–300 L (53–79 US gal), so 65 gallons is within that published band. The rating does not assure a target temperature in a cool room, an uncovered aquarium or a low-flow placement. Confirm that the item is the 150 W / Type 3666 North American 120–127 V version and independently check the aquarium temperature.
Explore this need in the finder →Can the thermocontrol+ e 150 be considered for a 79-gallon marine aquarium set to 90°F?
The manufacturer identifies Type 3666 for fresh and marine water, up to 79 US gallons, and the operating manual includes 90°F at the top of its stated adjustment interval. This is a match to documented limits, not a husbandry recommendation or proof of measured stability. Check the package's North American voltage, vertical placement, marked waterline and actual temperature independently.
Explore this need in the finder →What distinguishes Type 3666 from the thermocontrol+ e 200 and 250?
The 150 W Type 3666 is the 327 mm (12.87 in) size with a 79-US-gallon upper screen; the 200 W Type 3667 is 386 mm long and rated to 106 gallons, while the 250 W Type 3668 is 431 mm and rated to 159 gallons. All three share WLAN-based adjustment and the same manual-stated 68–90°F span, so aquarium volume and clearance—not wattage alone—separate the sizes.
Explore this need in the finder →The EHEIM thermocontrol+ e 150 is a 150 W, digitally controlled, WLAN aquarium heater. This assessment is for the North American Type 3666 configuration, not the similarly named classic thermocontrol e150 or the analog Jäger 150 W. EHEIM's operating manual places Type 3666 in an approximate 200–300 L band, or 53–79 US gallons, and lists a 327 mm (12.87 in) body. Those figures help screen model size; they do not estimate heat loss or guarantee a target temperature in a particular room.
Its useful distinction is remote setup, not a new tank-size rule
The thermocontrol+ e family uses WLAN programming rather than the direct manual setting of EHEIM's classic glass heaters. EHEIM documents smartphone, tablet or computer control, a wireless connection to certain other EHEIM.digital equipment, status indicators and optional e-mail notice when temperature deviates by about 2°C. The manual shows a local setup sequence using a WLAN-capable device and a browser. That makes the feature set more involved than a simple heater dial: check that you are willing to configure the network and follow the exact manual before relying on its alerts. The manufacturer also says the heater cannot cool water, so it is not a temperature-cycling device by itself.
Within the four-size line, 150 W is the shortest and smallest-capacity option: the 200 W Type 3667 is rated through 106 gallons and is 386 mm long; 250 W Type 3668 reaches 159 gallons and is 431 mm; 300 W Type 3669 reaches 264 gallons and is 486 mm. All are 32 mm in diameter and share the same listed adjustment and WLAN family features. A larger wattage is not automatically the right choice; actual water volume, room temperature, circulation, tank cover and clearance still matter.
Read the setting-range discrepancy conservatively
The exact product page describes adjustment from 18–32°C, but the English operating manual states 20–32°C ±0.5°C and gives the Fahrenheit range as 68–90°F ±1°F. Those lower endpoints are not equivalent. For this US-oriented finder record, the explicit Fahrenheit range in the manual is used rather than silently converting the page's 18°C minimum into a wider screen. Check the included instructions for the exact model supplied. Neither a documented setpoint nor EHEIM's control-accuracy figure determines an appropriate livestock temperature or proves the water in a particular aquarium is at the setpoint; use an independent thermometer and species-specific guidance.
Plan vertical placement and the wireless waterline
The manual instructs vertical in-tank mounting, strong water circulation and respecting the minimum-water mark. EHEIM calls the unit fully submersible, while its product page says best WLAN reception requires immersion only to the marked water level. Because radio reception and aquarium placement can interact, check the marks and mounting diagram on the supplied device; the reviewed English text does not give a numeric maximum immersion depth. The heater is glass, not documented as shatterproof. Its dry-run circuit breaker is a safety feature, not permission to run it outside water. EHEIM also specifies cooling time in the manual before normal removal.
The manual lists Type 3666 among the 120–127 V / 60 Hz group, alongside a distinct 220–240 V supply group for Types 3666–3669. A US retailer listing bridges the 150 W model to UPC 720686011670, but the package and unit labels remain the final check. The official EHEIM exact-model image shows the right 150 W product but visibly reads 220–240 V, so it remains rejected. This page instead uses a wattage-matched photo tied to the US retailer listing; no voltage label is legible there, so check the package and unit. Do not treat a correct model name or photo as proof of electrical compatibility.
Bottom line: Type 3666 is worth comparing when a freshwater or marine aquarium is within EHEIM's approximate 53–79 US-gallon band, an adjustable setting is required, and the 12.87-inch vertical heater fits. The principal tradeoffs are WLAN setup, a glass body, a marked waterline and the unresolved online-page/manual minimum-temperature difference. This is a source-based review, not a hands-on test.
Sources: EHEIM's thermocontrol+ e 150 page, the Types 3666–3670 operating manual, and the US retailer's thermocontrol+ e listing.
Key specifications
Key details at a glance
| Rated heater power | 150 W |
|---|---|
| Manufacturer aquarium rating | 79 US gal |
| Lowest thermostat setting | 68°F |
| Highest thermostat setting | 90°F |
| Temperature control | Adjustable thermostat |
| Supported water types | freshwater / saltwater |
| Installation route | Fully submerged, in-tank |
| Heater length | 12.87 in |
| Electrical supply | 120 V |
| Line frequency | 60 Hz |
Use the exact model’s instructions for operating limits, supplied equipment and version differences.
Sources for this review
Sources for this assessment
Check the complete aquarium setup
Use the finder to compare documented tank size, water type, installation and temperature-control fit. A match does not guarantee the keeper's species-specific target or measured performance.