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Eheim Thermocontrol heater review

EheimThermocontrol aquarium Heaters

A review of the Eheim Thermocontrol heater range for fresh and saltwater aquariums.

Eheim Themocontrol Heater

The Eheim Thermocontrol heater often referred to as the Eheim Jager, can be found on sale in most aquarium shops.  As heaters go they look pretty standard but as with all Eheim products (that I’ve tried so far) they have a high level of quality as standard.  These heaters often stand out as they are quite large in comparison to other heaters of the same power.  This is due to them operating on a single coil, rather than multiple, which makes them more efficient.  This heater has the added feature of user calibration and also has a built-in safety cut off.


Unboxing the Eheim Thermocontrol Heater

The Eheim Thermocontrol heaters box is pretty sturdy, inside you will find the heater itself with a long 1.7m power cable, an instruction book, rubber suckers and bracket, and some protective packaging.  As mentioned, the heater is quite long, it feels sturdy and the operation seems simple with a temperature dial at the top.  Just under the temperature setting dial is a little red arrow.  This is used to calibrate the heater, this means that if over time the heaters calibration drops out a little, then you can correct it quickly and easily.  They tend to be pretty well calibrated out of the box though.

Eheim Thermocontrol heater




Calibrating the Eheim Thermocontrol

The calibration of this heater is very simple.  To calibrate the heater:

  • Set the heater to the required temperature.
  • Add the heater to your aquarium.
  • Add an accurate thermometer.
  • Keep an eye on the heater until it switches off (stops heating).
  • Check the temperature it turned off at using your thermometer.
  • Adjust the red arrow until it lines up with the temperature that the heater turned off at (Do not move the temperature dial itself, the red arrow only).
  • The heater is calibrated.
  • Re-set the required temperature and test.


Setting the Eheim Thermocontrol heater up

Setting this heater up couldn’t be easier, the dial on top of the heater is easy to adjust and to set your desired temperature.  The rubber suckers that come with these are the biggest letdowns of the heater, whilst they do work, they certainly are not the best and I found that the heater was easily knocked off the side of the aquarium.

The heater can be positioned either vertically or horizontally, as with most heaters, but keep in mind the length of it.  If the heater touches the bottom (substrate) of your aquarium, then you will need to set it up horizontally.

The heater is fully submersible and has an easy to read ‘minimum water level’ with a line around the top of the heater.

The Eheim Thermocontrol has a built-in safety cut off.  This means that if the water level drops too low then the heater will automatically switch off to prevent damage to the device itself or your fish.  This safety cut off also works if the heater gets too hot.  This gives an added level of protection for your fish as it won’t overheat the water if it malfunctions.



Eheim Thermocontrol Set up



Is the Eheim Thermocontrol effective?

The Eheim Thermocontrol has now taken the spot of my favourite heating device for my aquariums.  I’ve had many different aquarium heaters over the years and these stand out as the most efficient and value for money.

They are reasonably priced, depending on the size of the heater they range between £16 and £25 at the moment, depending on where you shop.

Due to their single-coil design, they heat the water more effectively and use less energy to do so.  This means that they are capable of heating more water than a competitor model of the same wattage, which means more money in your pocket (lower electricity bill).

The heater itself is durable and easy to use and the added safety cut off gives a good amount of peace of mind.  It is suitable for both fresh and marine aquariums and has a long power lead for larger aquariums.

I have been running two 150W Eheim Thermocontrol heaters in my 580-litre tank for quite some time now.  They are really effective, they keep my aquarium at a very stable temperature and have certainly reduced my electricity bill since I switched over to them.  I previously had two 300W heaters of another brand doing the same job, it cost more money to run and the temperature varied a lot more.

The only issue I have had with them is the previously mentioned rubber suckers, they are quite weak and larger fish will easily knock the heater off the side of the aquarium, so a potential upgrade would be to change out either the rubber suckers or the entire holder for something more effective.




Overall I am very happy with these heaters and I would be hard-pressed to switch to any other.  They give a consistent temperature and use less electricity than other models that I have used.  The build is high quality and the ability to re-calibrate them is really handy.

I would certainly recommend an upgrade of the rubber suckers used to attach the heater to the side of the aquarium, they are pretty poor and not effective, so they definitely require an upgrade.

These are a great bit of kit and great value, in my opinion, and they can be even more effective when used with an additional temperature controller such as the Inkbird 306A, which you can find here.  If you’re looking for a reliable, effective and safe aquarium heater that won’t break the bank then look no further than the Eheim Thermocontrol range.

So if you’re looking for a new heater at the moment, give the Eheim Thermocontrol a try, they are available here:






(As an amazon associate I earn from qualifying purchases).






Want to compare another heater? Check out our review on the Betta compact heater here.


Let us know your thoughts on these in the comments.

About the author

James @Seriously Fishy

I am a fish keeping enthusiast with over 20 years experience. I currently keep American Cichlids (CA) which are my favourite fish to keep so far. I started Seriously Fishy as I noticed a large volume of people on various web pages looking for help with Aquarium basics. I created the first Seriously Fishy book to solve the issue in 28 pages, that led to the Seriously Fishy UK fish forum and blog.

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