Cracked heater... Still worked

[Sfork]

So for about 1+ months now my tank has been a steady 82.3 F. The first thing I did maybe 2 weeks ago was unplug the heater during the day to verify that it was indeed the heater heating the tank ( I could never catch it with the light on) Came back later that day and the tank was about 76.5 I pulled the heater out and turned it down a notch. I turned the notch down every 2 -3 days, until I hit the bottom(still actual temp was 82.3). Today I pulled out the heater to clean it, suspecting some tough algae had covered it or something. I find it looks kind of wet inside (but not flooded) I inspect it even more to find an impact type crack.

Not really sure what caused it but I threw it out and pluged in my spare 100w and everything is good now . I guess I'm super lucky I didn't fry my tank but I'm even more amazed it continued to work for 1+ month.

 

[Euphyllia]

Luckier than me. Last year my heater exploded, and once the smoke cleared, I had to find and gather the shards of glass from around the tank.
Could you have possibly cracked it while taking it out to adjust the temperature?

 

[Sfork]

I don't think so. The only time I pulled it out was because it was hitting 82.3F. It may have been when I changed its location a few months ago and the water didn't get in until last month.

 

[bondolo]

Your's wouldn't happen to be be a Hydor Koralia would it? My symptoms are the same as yours and it's heating to almost exactly the same temperature. From reading various forums some people report a quality issue on the Theo heaters and thermocouples that slowly go off spec. Others with the same heater never have a problem.

 

[Sfork]

It was actually! Mine was a 200W version.

 

[bondolo]

Same model and wattage as mine. I guess I will use the Theo for warming water changes and invest in an Eheim Jager for my tank.