Aqueon Heater Not Working: Find Out Why

Have an aquarium that you care for a lot. Got a heater for it, but for some reason, it is not working.

So is the Aqueon heater not working

Aqueon heaters could malfunction due to various reasons. It may be due to a power supply issue, a thermostat issue, or even due to the heater being broken. The heater can be tested in a small bucket to see if it is truly broken. Damaged heaters need to be replaced. 

There are many more aspects to why your Aqueon heater may not work. You can read all about it right here!

Aqueon 50w Heater Not Working

There could be a plethora of reasons why your Aqueon heater may not be working. Diagnosing the problem can be done in various ways. So let’s find out how to tell if the Aqueon heater is working.

The following aspects are true for any aquarium heater, not just Aqueon heaters. 

Check the Aquarium Heater is Plugged In

First, make sure it has power by checking the plug. plus whether or not the plug is turned on.

There are a lot of black plugs and wires that come with heaters. Hence it would be understandable if you forget that the power is disconnected.

If it is connected to a power strip, try another outlet. Cheap four- and six-socket converters often fail in one socket.

Use a Thermometer to Check the Temperature

To see whether the aquarium water is too hot or too cold, you may use a thermometer. Then, after adjusting the thermostat, you should verify the set temperature.

The water in the aquarium is at least 25 degrees Celsius. And the heater may be pre-set to that temperature. If that happens, the heater won’t activate. or display the “on” functional light.

Since the water temperature exceeds the heater’s preset temperature, this is the result. Therefore, it will remain off till the water temperature decreases.

Double-check the Thermometer

Inaccurate readings from thermostats are common. It’s possible that your digital thermometer needs new batteries.

Some thermometers may have had their probes dipped out of the water. It may be because the cable they were attached to was wet. Because of this, the colder room temperature is read in the measurement.

If you want reassurance and an alternative view, use the alternative thermometer.

Check the Aquarium Heater Light Is On

Aquarium Heater Light Verification

The thermostat on the heater may be preset to 24 degrees Celsius. But the actual temperature of the water could be much lower.

In this situation, make sure the “on” light on the heater is glowing after you’ve turned it on. At the end of the glass tube, there is often an orangish LED light that is installed.

Spend a little bit of time analyzing the heater’s performance. It is not unusual for Aqueon heaters to kick on for a few minutes or seconds. Then, after each round of heating, take a little pause in between the sessions.

If the light is turning on and off, this indicates that the heater is operating correctly. Everything is going about their business as usual. Allow the water some time to warm up.

But if the aquarium heater light on but not working, then the heater may be broken. Test the heater in a smaller body of water and replace it if it still does not work.  The process of testing will be discussed later. 

Examine the Heater to Know If It Is Warm

Place your hand carefully near the submerged heater. Check for the presence of heat by touching it.

Check the submerged heater to observe if any wavy patterns are forming. These streaks represent convection currents surrounding the heaters. If they are, then everything is functioning normally.

Test the Temperature Control Knob

Test the Temperature Control Knob

The heat switch could be activated. The water temperature, however, may be abnormally low. There would therefore be safeguards in that regard as well.

First, make sure the top-mounted control knob is in the correct position. There might be a numerical display on certain types of aquarium heaters. Albeit, the majority of heaters feature just the barest “+” and “-” symbols.

Try turning the dial in the water to check if the heater turns on. If so, the bar was simply set too low.

Check the Heater for Damage

The heaters in aquariums that are submerged don’t always work. Most Aqueon heaters, however, are designed to malfunction when the power switch is in the off position.

Taking an electric water heater away from the water is dangerous. Remove the device from the suction cups with caution only after you have turned it off. And you have unplugged it.

Glass tubes, electrical cords, and plugs should be removed if they show any signs of wear and tear. Put brand new ones in the damaged ones’ place. Don’t throw away the receipt; you may need it later.

It’s best to have a backup if you want to maintain fish without any hassle. Alternatively, you might want two smaller models. With this setup, one will activate in the event that the other one fails.

Test in a Smaller Space

Use a bucket of water to diagnose whether the aquarium heater is functioning properly.

Locate a bucket and fill it with water to a depth of between 5 and 10 liters. Get a thermometer and compare the water temperature before and after installing the Aqueon heater.

Light and water currents should be checked. A method and location for doing so have been explored.

There has to be at least 30-60 minutes of waiting time. The heater is malfunctioning if the waiting time is noticeably longer than that.

Aqueon Heater Not Turning On

There could be a few reasons why the heater is not turning on. Let us see what they may be. 

Faulty Product

You should attempt to test out your new heater. Check it out in a more limited body of water first. Simply repeat the steps we’ve already given you.

A brand new heater is replaceable. But only if there’s an issue right from the bat that wasn’t your fault.

Ensure that a comprehensive check has been performed on the heater. If there is a fault,  you may still return it to the retailer for a refund.

Not a Good Heat Proof Appliance

Alternatively, you might use an aquarium heater made entirely of glass. Alternative materials that degrade at high temps might be used.

You might have set the thermostat at a higher degree and the room temperature may drop. In that scenario, the heater will kick in.  It’s possible the temperature is too high for the aquarium heater.

The various degrees might result in a non-working situation. Or perhaps outright damaging the heater.

Power Supply Issue

The problem with the power source might be one of two types. It might be the fuse or the plug itself that is the problem.

Earlier, problems with the plug and the fuse were brought up for discussion.

It Needs Rest

Perhaps your fish tank has recently finished a period of intense activity. This might mean it needs some time to get back on its feet.

Also, it may have been in use for a long time. Therefore, it may malfunction as a result of becoming old. 

However, test it out first in a more manageable setting before committing to a full replacement. We discussed testing in limited space already. 


Why Does My Aqueon Heater Turn Off?

Automatic shutoff for overheat protection is standard on all Aqueon heaters. The heater will begin operating as soon as it is plugged in. In most cases, the thermostat determines when to turn the heater on and when to turn it off.

Can The Aqueon Heater Be Fully Submerged?

The vast majority of Aqueon heaters may be completely submerged in water. The heaters are equipped with suction cups, allowing them to be positioned in either a vertical or horizontal orientation inside the aquarium.

Do Aquarium Heaters Stay On All The Time?

The heaters in aquariums are on all the time. The water temperature is maintained just a few degrees of the predetermined point thanks to an inbuilt thermostat. These shut off the heating when the water gets to the preset temp. 


And with that we know so much more about Aqueon heater not working. The problem may be as simple as the plug not being plugged in. or the heater itself may be broken.

There are many ways to diagnose the heater. Our article should give you all the knowledge you need.

Good luck!

Howard Parker

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