How Long Do Aquarium Heaters Last?

If you’ve decided to graduate from keeping a single goldfish in a goldfish bowl, the chances are pretty good you’ve discovered the importance – and downright need – of a quality aquarium heater.

An aquarium heater is an essential part of your fish keeping system. All fish are cold-blooded, regulate their temperature based off of surrounding water temperature, and do a whole lot better – and survive a lot longer (leading happy, healthy lives) when water is maintained at a consistent temperature.

Unfortunately, though, like everything else man-made aquarium heaters do eventually “burnout”.

Granted, top-quality options are going to give you at least a couple of years of regular and consistent use before showing signs of wear and tear.

But you’ll want to know what to look for, know how often you should be replacing an aquarium heater, and understand why they fail in the first place all the same.

That’s why we’ve put together this detailed guide!

Recommended Aquarium Heater:

How Often Should I Replace an Aquarium Heater?

While it’s impossible to say exactly how long your specific aquarium heater is going to last (if only because the longevity of a top-of-the-line options going to differ wildly from a knockoff, cut rate option), you can pretty accurately ballpark the lifespan of this important equipment.

As a general rule of thumb, aquarium heaters (especially those that run 24/7, every day of the year) are going to give you anywhere from two years to three years of life.

After that these pieces of aquarium equipment start to sputter, run the risk of burnout, and either can’t heat up your tank water any longer or superheat your tank water – both major problems you need to avoid.

There are some aquarium keepers that like to swap out an essential piece of technology like this every year or so. And with today’s top-of-the-line heater units becoming less expensive all the time (and modular enough to “hot swap” when necessary) that might not be a bad idea.

Your budget will influence whether or not you decide to go down that road, though.

When you get right down to it, expect to get about two or three years of use out of your aquarium heater. After that, though, you’ll need to start shopping for a new one!

Why Do Aquarium Heaters Fail?

There are a couple of different reasons that aquarium heaters fail, but the most common reason that these units “go on the fritz” has to do with their electronic thermostats.

The thermostat design in almost all aquarium heaters (even those that are considered to be the best of the best) leave a little bit to be desired.

Many feature very simplistic circuit topologies combined with less than super high quality components, resulting in a thermostat control module that is finicky at best – and also features a lot of failure points.

If you’ve ever noticed that your aquarium heater maintains perfect water temperature levels for the first six months of its life but then starts to get a little wonky the problems can almost always be tracked back to a thermostat control issue.

On top of that, the design of these thermostats make them very susceptible to long-term heat exposure problems.

If you are running a heater on a regular and consistent basis, and electrical load is going to be shooting across that thermostat controller almost all the time. That’s going to cause a lot of heat, that heat is going to cause problems with core components, and before you know it you have a meltdown kind of situation.

Another common problem, though, has to do with the actual heater core itself becoming compromised.

A lot of manufacturers sell their heater systems telling customers to submerge the unit fully, but some people still like to run their heater cores poking at least a little bit out of the water line.

Because these units have been designed to have the heat they generate synced away by the water around them (a much more efficient thermal transfer than with air), the exposed components superheat and quickly become compromised.

Even worse, though, is that it’s possible for lower quality heater components to be compromised even after they have been fully submerged.

Faulty manufacturing, poor quality control, or less than watertight seals can all cause your heater to become “dead in the water” (pun fully intended) sooner than you would have expected.

This is why it’s so important to invest in a high quality option with a reputation for durability and reliability.

How Long Should My Aquarium Heater Be On?

Truth be told, you’ll get the best results using aquarium heaters that are “always on” but have the most advanced thermostat control modules possible to turn the unit on and off as necessary – maintaining a temperature range that you’ve adjusted.

If that can happen, though, you might want to get your hands on time to or controllable aquarium water heaters.

The systems allow you to tinker with and toy with the water heating schedule, giving you a chance to sort of figure out what works best for your underwater environment.

At the end of the day, though, the best aquarium heaters are always going to be the “always on” systems. You don’t want to have to babysit something like this every single day – or even every hour of the day.

Especially not when water temperatures that are too hot or too cold could kill everything in your tank.

How Do I Know If My Aquarium Heater is Working?

The best way to know that your aquarium heater is working is simply to check your water temperatures on a regular basis.

It’s not a bad idea to get used to checking water temperature every time you feed your fish.

This’ll give you a good idea of whether or not your temperatures are consistent, how your temperatures are fluctuating, and whether or not your aquarium heater needs to be swapped out.

If you’re seeing water temperatures that are in the same range on a regular basis (within a couple of degrees, anyway), the odds are pretty good your water heater is working the way it should.

If, on the other hand, you’re seeing water temperatures skyrocket – or water temperatures plummet – you need to get your hands on a new system.

The one you’re using right now isn’t working!