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How to fix Fluval E Series Heater E1 issue

When using your Fluval E50, E100, E200 or E300 Advanced Electronic Aquarium Heater, you may see the LCD screen of the device display a E1 message. The screen may also flash between the red, blue and green colors.

You can check out the troubleshooting guide at Aquarium Blueprints to see how you can potentially fix this error message and get the device to work normally again.

What does the E1 error indicate?

If your E Series heater is showing E1 on its display screen, then it means that the device has detected some kind of problem. As a result, it has turned off power and is no longer heating the water in your fish tank.

How to fix the E1 issue with the E Series

In order to fix this error code, we recommend that you take the following steps:

1. To start off, we recommend that you unplug the power plug of your E50, E100, E200 or E300 from the power outlet.

2. Next, you should check to see if the water level in your fish tank is above the minimum water line that appears on the heater.

If the water level in your aquarium is below the line, then make sure you add more water. Alternatively, you can move the heater further down the tank.

3. The E Series should not be submerged by more than 39 inches (or 100 cm) below the top of water in your aquarium. Otherwise, you may see the E1 error show up on the LCD display.

4. We also recommend that you clean your heater as the mulm or mineral deposit could be causing this problem.

You should follow the steps laid out in our previous tutorial to see how you can properly remove the heater from your tank water and then wipe it clean.

5. The E1 error with alternating flashing colors won’t go away, even if you make several potential fixes, unless you unplug the heater from the power outlet.

Afterwards, we recommend that you wait at least 30 minutes for the heating core to cool down to the same temperature as your tank water.

Once half an hour has passed, you can plug the device back into the power outlet.

If the E Series is fully reset, and it detects that there aren’t any abnormal conditions, then the heater should start working normally again. The E1 error messages should no longer show up on the LCD screen of your E50, E100, E200 or E300 as well.