Top Fin Aquarium Heater Not Working

Top Fin Aquarium Heater Not Working

If you’re getting started in the fishkeeping business, then you’ll need a heater. Most fish require a temperature above 80 degrees Fahrenheit, a temperature only realistically attainable with a heater. Especially if you’re keeping tropical fish a heater is a must-have.

But if you’ve brought your heater home and it doesn’t seem to be heating up your tank, then what’s going on? Why is your Top Fin aquarium heater not working?

Your Top Fin aquarium heater may not be working due to a faulty thermostat or damage to the heater during transport.

Check the light to see if it’s turning on and carefully place your hand in the water near the heater to see if you can feel the heat emanating from it.

There are a lot of reasons your top fin aquarium heater may not be working, but most of the time, you should just contact the store you bought it from and see if they’ll get you a new one.

The rest of this article will walk you through how to diagnose a malfunctioning heater and what to do about it.


Why You Need a Heater

For most fish tanks, you probably need a heater to keep your fish safe. Fish generally prefer a temperature range from 75-80 degrees Fahrenheit (23-27 degrees Celsius) or higher.

During the winter, temperatures in your source water will affect the water in your tank, making a heater an essential part of your tank for the health of your fish. Temperatures in a tank can also cool or warm depending on how hot or cold the room is.

As such, during the winter months, when the water running through the pipes is freezing and the air in your home is cooler, fish are more susceptible to the cold and need a heater to keep their tank environment suitable for living.

If you’re close to the equator in a climate that’s warm year-round, then a heater might be option, but for most fish keepers, a heater is a necessary part of the tank setup.

How Do I Know If My Top Fin Heater Is Working?

The simplest way to know if your top fin heater is working is to turn it on, give it some time, and then place your hand in the water near it. You should be able feel the warmth emanating from the heater the closer you get.

Do not directly touch the heater. Surprising as it may seem, it’s hot. This is the quickest litmus test to ensure that your heater is actively pumping out heat, but you can also wait for 24 hours and take a temperature reading on your tank.

Some heaters come with a built-in temperature gauge, but you can use a backup one to be sure. If the heater is working properly, you should see a notable temperature increase in your tank.

A Top Fin heater is submersible, meaning that it must be in the water to work properly. Whatever you do, don’t do a water change while the heater is on and let the water level drop below the heater. This runs a high risk of making the heater crack, rendering it useless.

Why Is My Tank Not Heating Up?

There are several reasons your tank may not be heating up. The first and most obvious you should check is whether your heater is broken.

Heaters are composed of a lot of sensitive and delicate parts, and whether you’re picking it up from the store or getting it shipped straight to your door, odds are that it’s already been on a rough journey from place to place.

As such, you need to test the heater to make sure it’s working before exploring other methods. If your heater is working (aka you can feel the heat coming off it), then the next likely cause is that the heater isn’t strong enough.

In general, you need 5 watts per 1 gallon in your tank. That means a 25 watt for a 5-gallon tank, a 50 watt for a 10-gallon tank, et cetera. Of course, you also need to consider the temperature difference between your home and the tank.

If you like to run your house cold―let’s say the mid-60s―then your heater has a lot more work to do to keep your fish tank warm. It’s something of a balancing act with how much wattage you need to find the perfect temperature for your fish.

Keep in mind that some fish prefer warmer or colder temperatures.

How Do You Turn on a Top Fin Aquarium Heater?

To turn on your Top Fin aquarium heater, all you need to do is plug it in. Be sure that before you do this, your heater has sat in the water for at least five minutes so that it has time to acclimate to the water temperature.

Once you plug it in, you should notice within half an hour that you can feel the heat coming from the heater.

By default, PetSmart’s Top Fin heaters are set to 78 degrees Fahrenheit, so if you want to adjust the temperature of the thermostat, you’ll need to turn the white dial at the top of the heater.

Doing so will let you adjust the ideal temperature range for your tank. Unfortunately, heater thermostats are usually 2-3 degrees off, so having an accurate reading from your Top Fin heater isn’t the best way of monitoring your tank’s temperature.

If you need to remove the heater to inspect it for any reason, unplug it and let it sit for 10-15 minutes before removing it to avoid the risk of breakage.

Final Thoughts

Heaters can be tricky to deal with since they’re made of so many sensitive components and require great care in a tank. Top Fin heaters are submersible, meaning that they have to be fully submerged in the water to work properly.

If yours isn’t working, it’s likely that you have a dud and need to take it back to the store for a refund or replacement.