# JBL PROTEMP External Aquarium Heater

The JBL PROTEMP external aquarium heater is designed to fit into an external filter’s water-return hose rather than sit inside the aquarium. Its digital display shows current and target temperatures, while the listing describes automatic temperature regulation and protection against overheating and dry running.

- [Original product page](https://bargainpostbox.co.uk/product/jbl-protemp-external-aquarium-heater)
- [View offer](https://bargainpostbox.co.uk/visit/jbl-protemp-external-aquarium-heater)
- Market: UK
- Language: en-GB
- Currency: GBP
- Brand: JBL
- Model: PROTEMP
- Category: Pet Supplies > Aquariums & Terrariums
- Price: 72.05 GBP
- Previous price: 94.90 GBP
- Discount: 24%
- Price checked: 2026-11-14T19:40:32.889Z
- Rating: 4.6 / 5
- Reviews: 6

Prices and deal status are the latest recorded data, not a guarantee of availability. Confirm the price and availability with the store.

## At a glance

- Fits into the water-return hose of an external filter. The listing says it cannot be used with internal filters.
- Digital LED display shows current and target temperatures side by side, with SET and arrow keys for adjustment.
- Listing claims automatic control from 20-35 °C and safety shut-off for overheating or dry running.
- Six adapters are listed for hose sizes 12/16, 16/22 and 19/25 mm.

## Pros

- External-hose installation keeps the heater outside the aquarium, if the setup uses a compatible external filter.
- Side-by-side current and target temperature readings make the set point and displayed water temperature easy to compare.
- Dry-running and overheating shut-off are listed safeguards, including in the described filter-cleaning scenario.

## Cons

- It is not suitable for aquariums using an internal filter, according to the product description.
- The heater and its connections require space in the filter return hose, and the listing says the hoses must not be kinked.

## Specifications

### Identity
- Brand: JBL
- Model: PROTEMP
### Dimensions and installation
- Weight listed: 908 Grams
- Listed aquarium capacity: External heater for aquariums from 10 to 600 litres
- Hose sizes: 12/16, 16/22, 19/25 mm
- Total length including hose connections: 35 cm
- Additional hose length: 2 x 2 cm
### Temperature and operation
- Adjustable temperature range: 20-35 °C
### Other details
- Manufacturer: JBL GmbH & Co. KG
- Country of origin: China
- Warranty listed: 2 year manufacturer

## Before you buy

- The 10 to 600 litre range is a listing claim. Suitability for a particular aquarium will depend on its setup and conditions. The described installation requires an external filter return hose, and the hoses must not be kinked. The listing also gives a total length of 35 cm including connections, plus 2 x 2 cm for the hoses.

## In the box

- External heater with ceramic heating element (Included)
- 6 adapters (Included): Listed for hose sizes 12/16, 16/22 and 19/25 mm.
- Cleaning brush (Included)

## A good fit for

- Aquarium keepers with an external filter and a return hose matching one of the listed adapter sizes.
- Buyers who want an external heater with a digital readout of current and target temperatures.

## Less suited to

- Aquariums that use an internal filter or have no compatible external-filter return hose.
- Setups without room for the heater and its hose connections.

## Customer feedback

Aggregate ratings lean positive, but the small number of ratings and a notable three-star share leave room for varied experiences. With no written feedback supplied, they do not reveal what customers liked or disliked. Treat the ratings as limited context rather than evidence of heating performance or suitability for a particular filter setup.

## Frequently asked questions

### Can the JBL PROTEMP be used with an internal filter?
The product description says it cannot be used with internal filters. It is intended to fit in an external filter’s water-return hose.
### What temperature can it be set to?
The listing gives an adjustable range of 20-35 °C.
### Which hose sizes are supported?
The listing names 12/16, 16/22 and 19/25 mm hose sizes and says six adapters are included.
### Does it switch off if it runs dry or overheats?
The listing claims safety shut-off for dry running and overheating. These are manufacturer claims, not independent performance verification.

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## Images

![JBL PROTEMP External Aquarium Heater — 1](https://bargainpostbox.co.uk/i/p2jjoTebrVagECACjus7_pc7PWeo5YVeCFNhGK19uXNcuwSA3xDtO3ocaWBZ6a5fSRtLL3xQrV0maKDaD7JjPTN-Ml8_PRIL8-JABGyWj4sBvSwUIgwHgqJA.jpg)

![JBL PROTEMP External Aquarium Heater — 2](https://bargainpostbox.co.uk/i/mXGFLo2tzObTt8k0LePPNAjajos7fYH_R8TgWF4Cy1NcrW9Ly-vzkNLoUjWiouLwvDUR82vmOojmOwO9n5GWLt2Y0sGI7sGgbHiSWBP0XI8t4dDJ5IC-f_Aa.jpg)

![JBL PROTEMP External Aquarium Heater — 3](https://bargainpostbox.co.uk/i/YcLaEhne2IvrK7OcTUXZBFze4vhlR6D7xC-JNlNwoPTDvND7dJ1KF3aDL-JL4_CR7gLJHHk5uimUmXTyCeAkqcyL2zTt97Uhbeo6lDOrPrBX7F_YpTChngD8.jpg)

![JBL PROTEMP External Aquarium Heater — 4](https://bargainpostbox.co.uk/i/sfLC95xU0N8iEiea5IuUeR3hX43wc46trW1ASA6TMACUQKjilo3WZ9Hc-7Y2i7pYkjMSRQNCn5k1UUQFPSWqE1YXn-Y6Cw41i5-opZdTbd2MZuMo3wI_G7aX.jpg)

![JBL PROTEMP External Aquarium Heater — 5](https://bargainpostbox.co.uk/i/TM4d731O7jz4sVzVebwTtGsLF1YvDMdbYWEMacpMkRwNvGdneRCsF2QGX37n8SRoSeIKFv7_moJERo4txt2OXzO1WRdxsRzrWlS3HXirPCCDQSBWK02Z5z8h.jpg)

![JBL PROTEMP External Aquarium Heater — 6](https://bargainpostbox.co.uk/i/JvJcBkgoSGmH60-bPUc4_y4zoUjx45sZPQiTV2vUsKsT3Qv5cE5BYVuOpziox05dwfP7P6pj2wJgDLkxO_magzrHlKGj-8xJ_aXkdUImof6ZC9e6rabhnt8P.jpg)

![JBL PROTEMP External Aquarium Heater — 7](https://bargainpostbox.co.uk/i/A-9wJ_2Q50kiL6aIns7fpZRMMD0wCQRpwM__R24W6oc__DRDCRvQTjGtrDIALMpkyfr2rx7hz571cxGSXr5bTM-H9lXCezJ2EbUlUEtn3iV1Bcehf-4XWVwv.jpg)