When using the M Series Submersible Heater in your fish tank, you may notice that the device is not working as advertised. To see how you can potentially fix this problem with this Fluval product, you can take a look at this troubleshooting article from Aquarium Blueprints.
Before we begin, it should be noted that this guide applies to the following products:
- Fluval M50 Submersible Heater
- Fluval M100 Submersible Heater
- Fluval M150 Submersible Heater
- Fluval M200 Submersible Heater
- Fluval M300 Submersible Heater
1. The first step you should take is to check out the light indicator of the Fluval M Series. The light should turn on when the heater is actively heating the tank water.
If you don’t see any lights, then it may indicate that the desired temperature has been reached. Having the light indicator turned off may also mean that the heater is not working normally.
2. If the M50, M100, M150, M200 or M300 is turned off, then you can try using a separate thermometer to check the water temperature in your aquarium to see whether or not your heater is malfunctioning.
3. You should also make sure that you placed your heater in the correctly position. We recommend that you place the M Series horizontally, near the bottom of the tank and close to the filter intake.
4. If you are using the Fluval M Series Submersible Heater, or have to unplug it, then it may take up to 12 hours for the desired temperature to be reached.
During this time, you should not unplug the heater or change the temperature dial.
5. Keep in mind that the ambient room temperature should be within 10 ºC (or 18 ºF) of the desired tank water temperature in order for the M Series to work efficiently. Otherwise, you will end up getting cooler tank water as the heater won’t be able to make up for the huge difference.
So, if the M Series is not heating up your water to be warm enough, then it may be due to your room temperature being too cold. If you have a room heater, then you may want to consider increasing it so that the room temperature is within 10 ºC (or 18 ºF) of your desired tank water temperature.
6. If you haven’t done so already, make sure you put a top cover on your fish tank as doing so will keep the heat from escaping and, therefore, better insulate the temperature of your aquarium.
7. You should also avoid putting your tank in areas that are breezy as the wind will cool down your tank.
8. Furthermore, you should also inspect the heater to see if there are any part of the glass that is covered in fish wastes and or mineral buildup.
You scrub these off of your M50, M100, M150, M200 or M300, you can check out this cleaning tutorial.
9. If none of the aforementioned steps help with fixing your Fluval M Series Submersible Heater, then it may be broken. In this case, you need to replace it with a new heater.