I have 6 heaters in 6 tanks. Every one has been set for a specific reason at a specific temperature. They are the "fully submersible" ones - I do not remember the specific brand at this time - but they were not cheap! Each has reliable heated its respective tank for over a year.

Now, all of a sudden for not particular reason, all of my tanks are at 80-85 degrees! The heaters have been turned down to 70 and the tanks are still peaking out!

It is not that hot here. The night temps are in the low 40's and 50's F. , the house never gets over about 78 or so.....at the max heat of the day.

What gives?????

Had any kind of power surge lately? I dunno, thats very odd.

Would have to ask the same question as Ceridwen, power surges or outtages would be the first cause. Unless of course...something caused the heaters to spontaniously combust inside.

I guess a power surge is a possibility - we certainly have had our share of nasty tornado weather and power "glitches". They are plugged into power bars with some surge protection and a separate breaker, but they are not really high powered expensive ones or anything. I guess I should start pulling them and trying them out in buckets of water with alternative thermometeres.

i would not want to electrocute any fish like stories told here!!!!!