Experience with heater malfunctions?

  • #1
Decided to get a Fluval M 100Watt heater for my 20 long (did not have one because of the horrible stories I have read about malfunction)
Have you guys had any experience with a heater malfunctioning? Any tips on using and installing a heater? (I'm a newbie to heaters lol). Tank is cycled, had fish in the tank for a while, and want a temp at about 76 degrees.
  • #2
No horror stories here, just one that stopped working. No fish loss, they adjusted to cooler temp when water cooled down, and then got back to normal when I got new one and it's been working perfectly.
  • #3
yes I had a heater fail and lost a pair of goldspot plecos.
  • Thread Starter
  • #4
yes I had a heater fail and lost a pair of goldspot plecos.
Oh no! May I ask what the brand was?
  • #5
I haven't had any malfunctions personally but they are not unheard of.

As for installing just set the required temp and install it. Best to let it sit in the tank for 10min or so before switching the power on. Also I recommend checking its accuracy with a reliable thermometer. The temp settings are often a bit off so you may have to adjust it a bit over time to get your water temp exactly where you want it.
  • #6
Just another tip in case you aren’t aware. Put the heater in at a 45 degree angle or so for better heat distribution and Accuracy in the tank.
  • #7
It's not uncommon for them to stick on and heat up your tank to the point of killing it's inhabitants.
  • #8
Keep a reliable thermometer in the tank and you should be fine. Many years ago I had a heater stay on and it killed all but one lone little cory. We moved into our new home but hadn't moved the tank yet. I wasn't keeping a close eye on things when it happened. Had I moved the tank over here before it happened I would have caught it before it caused any harm to the fish.

Now I check the thermometer several times a day so would catch it if something was going amiss. That and one can tell at a glance at the tank if the light is staying on longer than it should. Had I still been in the same house when the heater stuck on I would have known it right away.

So in the many years I have been in this hobby I have had one stay on and only one just quit working. I have to say that is a pretty good track record. I have one heater that I have used every winter for at least 20 years and it still works as well as it did when new. The name on it is Radiant.

I know some heaters are designed to be fully submersible (most of mine are) but I cannot bring myself to put a power cord in any of my tanks. I always situate my heater vertical with the top of them sticking out of the water. I always have to remember to unplug them while doing water changes. Fortunately so far I've never forgotten to do so. It helps that the heater plug is right behind my water changing buckets so easy to remember to both plug and unplug.
  • #9
oh yer. I only buy heaters these days that automatically turn off if they are out of water. I had ones glass explode in a tank once.
  • #10
Just another tip in case you aren’t aware. Put the heater in at a 45 degree angle or so for better heat distribution and Accuracy in the tank.
Interesting. I had not heard this before. I have a heater horizontal near the bottom. Thinking heat rises so heat at the bottom should be efficient. But this heater seems to always heat to 78 degrees no matter what I set it to. Trying to keep the tank cooler than that. Currently set at 72, but tank is at 78. Could that be due to the thermostat not working right with horizontal orientation? Or maybe water is cooler at the bottom. Do not think that should be the issue. I will give it a try.
Charlie’s Dad
  • #11
I have an Inkbird thermal controller on my heaters. You set what temp you want and it controls and maintains that temp. Very very nice. Available on Amazon for 35 bucks or less.

You won't regret it if try it!
  • #12
I think YouTube channel is where I also heard about keeping a heater kept slightly diagonally or at a 45, if not all the way horizontal, so rising heat doesnt falsely trigger the thermostat to turn off.
I started to keep mine either at a 45 or at least tilted somewhat.

Gel0city, FWIW, I've got 2 Fluval M heaters like the one you mentioned. One is a 200w (came with tank my friend gave me) and the other a 300w. So far no issues with them. I like how there is a click on the thermostat knob when its rotated. Most knobs on other brands dont have the individual click on the settings

Also, you may want to invest in an external heater controller if you have concerns with theil thermostat failing and leaving the heater on.

When using a heater controller, you can set the heater's thermostat knob slightly above its normal setting where it keeps tank exactly at temp you want. Then plug heater into the controller. Next the controller plugs into the power outlet and has a separate wired thermometer that goes into the tank.

Finally set the controller to the temp you keep your tank and you're done. Some controllers have separate temp thresholdsfor both on and off temps. The controller is basically a relay that switches on/off the power supply to your heater is plugged into. When controller detects the tank dropped below the set threshold, it gives power to the heater. It turns off power supply when max temp threshold is reached.

Since you already turned the heater's thermostat just slightly above the setting it's normal kept at, if the controller actually failed and kept the power supply on to the heater, the heater's thermostat will turn off. If controller fails in this manner, the tank temp only rises a few degrees b/c heater thermostat still turns it off.

Basically, a controller gives you a 2nd layer of insurance again a heater staying on.

Heater controllers cost anywhere from $20 to over $100 ( professional models found on Jehmco website).

Finnex makes controllers (and heaters as well).

A lot of people are using the Inkbird brand of controllers found on Amazon. They have different models, and make some that even control freezers and chillers, humidifiers and all sorts of equipment.

***edit, Charlie’s Dad refers to the Inkbird above, ha. While writing this response he must have posted before I did and I just now read it. Ha! Funny how we both were thinking same thing at same time!****

The Inkbird model for aquariums (description says the wires thermostat is submersible) I believe costs around $24-$30 if I remember correctly. Members on this forum report they work well with no issues.

When I first heard about the Inkbird controllets and saw them on Amazon, my first thought was "what the heck is this weird brand?" I researched them and they appear to be a quality product from what I've seen.

Later in the Spring, I probably will buy Inkbird controllers for our 65g and 75g tanks, since I have extra heaters I am not currently using and I can meet the controller power 2 heaters at same time per tank for better heat distribution.

I also use Aqueon, Aqueon Pro and the Top Fin heaters that come with their kits. All of those never had a heating issue related to the thermostat sticking on (or not coming on for that matter).

I did have one issue with the new version of the Aqueon (non-pro) where the knob seemed to have to much resistance when turned back and forth, and it popped off. I took it back to PetSmart and they exchanged it, no problems with new one. Aqueon does have a lifetime warranty.

I try to keep the receipts for any aquarium equipment I buy and scan receipts to a file on my computer. Most manufacturers are very good regarding warranty claims. Hydor just honored my claim, all I needed to do was send them a receipt and tell them part number and description of problem, and I received replacement 3 days later!

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