View Full Version : Fluval E Series Heater Not Working

01-18-2012, 02:46 AM
Hello, I recently setup a new 20 gallon tank. I got a 100w Fluval E Series heater for it. I followed the directions and the thermostat is set to 77 F. The heater has been running for about 5 hours but the temperature is going down. Currently it's 73 F! What should I do? I transferred my guppies from a 5 gallon tank to this one. Unfortunately during the transfer I set my old heater on the carpet and it has melted carpet on it now! Maybe I can clean it off?

01-18-2012, 02:59 AM
hmm i was thinking of buying one of those... 5 hours should be plenty of time for that heater to heat it up... hows the circulation on the tank? not that it should really matter all that much...try turning the setting up to 80? see if that helps.

01-18-2012, 03:05 AM
Circulation is good, I have a Fluval 205. Turning the temp up shouldn't matter. According to the manufacture the heater has a thermostat and should turn on full time when the temp is below the desired temp. But I'll try turning it up to 80.

01-18-2012, 03:17 AM
Turning it up to 80 made the LCD screen start flashing since now the temp is off by more than 3 degrees Celsius. I was able to get the melted carpet off my old heater pretty easily, it just peeled right off. I scrubbed it a whole bunch too to make sure there was nothing bad on there. I have no idea of the wattage, but it's designed for a 5 gallon tank, so it's tiny. I figured it's better than nothing.

01-18-2012, 03:31 AM
Hmm, it actually started showing a Low Flow error now, after like six and a half hours. I had it positioned just inside the filter output. I thought that was a good flow spot. I tried moving it outside the filter output so it's in the corner since the water seems to move around more there.

01-18-2012, 03:52 AM
Weird the 100w heater is almost overkill for a 20 gallon tank. I would take it back since it's not working. Then if you put 2 50w heaters in there if 1 should someday fail the other one could still keep the temp from falling.

01-18-2012, 07:16 AM
Temperature started to go up, so I turned off my old heater. Temperature continued to rise and is now at 76 F. I'm not sure if it was just the placement, or if unplugging it and re-plugging it in fixed things. Anyways it seems to be working now.

01-18-2012, 07:22 AM
Keep an eye on it for awhile to ensure that it does shut off as expected.

01-18-2012, 07:50 AM
even though 100w is a bit overkill for a 20gallon, if the room that the tank is too cold, it will just heat up to 100w, and might not be on the exact temp you want it to be.

what i would do is, unplug the heater for around 10-15 minutes for it to adjust to the tank's temp. then plus it back in.

here is a good article on wattages of Heaters (http://freshaquarium.about.com/od/heating/a/heatersizeguide.htm)

01-18-2012, 04:17 PM
Thanks pjaldave! I checked out that article. The lowest temp my homes thermostat is set for it 62 F. So I guess with the tank temp set to 77 F the difference is 15. According to the article 100w in a 20 gallon should be good for an 18 degree difference. So it would seem that I have the correct heater. This morning the glass thermometer in my tank is reading about 76 F. The house thermostat says it's 70 F inside. The Fluval E Series heater is set to 77 F but the LCD said the current temp is 74 F. So it seems like the heater is working, the screen is just displaying bad info. This was not the case yesterday, my glass thermometer was reading low temps too! It was always reading about one degree higher than what the heater said though. I'm trying what you suggested. I've unplugged the heater and in 20 minutes I will plug it back in.

Lady Hobbs
01-18-2012, 05:12 PM
If the wattage is too low for the volume of water, all it will do is turn off and on constantly because it will never catch up. You are better off using a higher wattage than a less wattage than needed.

01-18-2012, 05:39 PM
Well it sounds like I have enough wattage, most of the time the ambient to tank temp it only off by 5 degrees. The most that it'll be off is by 15 degrees. The article that pjaldave linked says 100 watts in a 20 gallon is good enough for an 18 degree difference. And according to the below video from the manufacture, at 2 minutes 51 seconds: "Dual thermal sensor technology also provides fast heat response. The Fluval E heater will stay on continuously until the preset temperature is reached. It will not cycle on and off like bi-metallic heaters."


01-18-2012, 06:18 PM
I called the manufacture and they seemed to think that it should be doing a better job, they suggested I return it. So I ordered a new one. I went with the 200w version this time since some people seemed to think I was a little under powered. The manufacture said it wouldn't hurt to go up in wattage. It was only $1.12 more to get the 200w. The new one should arrive on Friday.

01-18-2012, 08:46 PM
I just replaced a Rena SmartHeater with a Fluval E. I originally had it in a corner next to the filter intake, but there just wasn't enough water movement there. I put it in the middle of the tank, between the filter intake and returns, and now it's bang on the set temp every day.

The room the tank is in is only 66 degrees F, so the heater is working hard to keep the tank at the right temp. I do see a slight drop overnight, only 1 or 1.5 degrees, but that certainly isn't enough to stress the fish who probably experience a bit of an overnight temp drop in the wild as well.

I will probably get another Fluval when my other SmartHeater dies; Rena is discontinuing production or I would have bought the same brand again.