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What to do if the Fluval E Series Heater is not working

The Fluval E Series is an advanced fish tank heater as it features an LCD screen as well as electronic sensors.

If your water heating device does not seem to be working as intended, then you can take a look at this troubleshooting article from Aquarium Blueprints to see how you can potentially get it to function normally.

Before we begin, it is important to state that this guide will cover the following products in the E Series:

  • Fluval E50 Advanced Electronic Aquarium Heater
  • Fluval E100 Advanced Electronic Aquarium Heater
  • Fluval E200 Advanced Electronic Aquarium Heater
  • Fluval E300 Advanced Electronic Aquarium Heater

1. The first step we recommend taking is to see if there are any errors being shown on the LCD screen of the heater.

If you see a green color, then it indicates that the temperature of your tank water is within range of the set temperature of the heater.

To see how you can deal with the different error indicators or codes with this device, you can take a look at the following articles:

2. If the LCD screen isn’t showing anything, then make sure that the E Series is plugged into the power outlet. You can also try using a different power outlet to see if the screen will turn on.

If you still aren’t getting any images, then you can try using a thermometer to test your water temperature. If the temperature is within your desired range, then it may indicate that only the LCD screen is defective. If the device doesn’t appear to be turned on at all, then it may need to be replaced.

3. Keep in mind that, for this Fluval product to work, the water level in your fish tank needs to be above the minimum water line label of the heater.

If the water level in your aquarium is below the line, then you can either add more water to the tank or move the E Series lower in the water column.

4. If you decide to reposition your heater, then we recommend that you also try to accomplishing the following placement suggestions:

  • Put the device in a horizontal or diagonal position.
  • Place it as close to substrate as possible.
  • Make sure that the heater isn’t touching any physical objects.
  • You should also make sure that there is enough water flow going through the heater.

All of these should help the device become more efficient at keeping the tank water heated.

5. Your E50, E100, E200 or E300 heater may also be covered with mulm and/or mineral deposits to prevent it from working normally.

To see how you can clean this Fluval device, we recommend checking out this post.

6. One last step you can try is to cool down the device before trying to use it again by taking the following steps:

  • Unplug the E Series from the power outlet.
  • Let the heater sit unplugged in the tank water for at least 30 minutes.
  • Take the heater out of the tank and then let it sit in the air at room temperature for at least 60 minutes.
  • Put the E Series back into the tank water. Make sure that the water level of your fish tank exceeds the minimum water line.
  • Let the heater sit in the water unplugged for at least 20 minutes.
  • Finally, you can plug the heater back into the power outlet.

If none of the aforementioned potential solutions worked, then it is likely that the device is defective. In this case, all you can do is get a replacement for your heater.