JBL ProTemp S (25-300w) (Safety Heater with Protective Basket)

JBL ProTemp S aquarium heaters use modern technology for both freshwater and marine tanks. A protective plastic guard prevents fish burns and protects the quartz glass. It has a safety shut-off if overheating occurs (e.g. when left out of water). The heater is fully submersible, compact, and easy to install vertically. Temperature is adjustable from 20–34°C via a clear dial, with an indicator light showing operation. Using a thermometer is still recommended for accuracy.

Features:

• Plastic guard protects fish such as suckermouth catfish from direct heat.
• Comes with dry run protection (turns off automatically when the water level drops or the heater is removed from the water)
• Fully submersible and very robust 2 mm safety glass.
• Direct temperature selection in °C.
• Diameter of glass: 29 mm
• Diameter on top: 36 mm
• Diameter with cage: 33 mm
• Diameter with cage + suction cup: 36 mm
• Length incl. cage: 220 mm

Technical specifications:

• temperature range: 20 - 34 °C
• accuracy: +/- 0,5 °C
• fully submersible
• run-dry-protection
• 4 years guarantee

The following sizes are available: 25/50/100/150/200/300W

 

FAQ

1. Heater feels only warm underwater
Normal. Heat is quickly dispersed into water, so it feels mild. Out of water, it heats up fast and can get very hot. Always unplug before removing from water.

2. Temperature not stable / big deviation
Heater accuracy is about ±0.5°C (up to ~1–1.5°C with measurement differences). Large deviations (5–7°C) usually mean incorrect adjustment, poor water flow around heater or faulty unit

3. Protective basket deformed
Caused by limescale buildup, which traps heat and leads to overheating.
Solution: Regularly descale (e.g. with JBL Clean A or pH Minus).

4. Do I still need to unplug during water change?
Yes. The safety switch is only backup protection, not a replacement for unplugging.

5. Can I replace the basket?
Yes, basket parts are sold separately (end, middle, and top sections with suction cups).