Is my heater Faulty

[Ollymoran]

I have a heater in my tropical aquarium and it is set to 25 degrees. When I woke up my tank temperature was at 24.7 degrees and my heater was off and did not come on. I double checked it was set to 25 and it was so I turned it to 27 and it came on. When I turned it down to 25 again it went off. Do these heaters heat it to exactly 25 degrees or do they actually give or take .2 or .3 degrees when the come off or on? Failing that is the thermostat on it knackerd?? It should not be because it is only 3 or so months old but don't want my fishies to freeze due to a faulty heater i dont know of.

Any ideas??

 

[Convict2161]

What kind is it? Doesn't sound to be faulty IMHO my heaters are set to 76 and tank temp is about 78.4-78.8

They will fluctuate a little from time to time. If it turned on when you raised it I wouldn't worry too much. Just keep an eye on your thermometer readings.

 

[Ollymoran]

What kind is it? Doesn't sound to be faulty IMHO my heaters are set to 76 and tank temp is about 78.4-78.8

They will fluctuate a little from time to time. If it turned on when you raised it I wouldn't worry too much. Just keep an eye on your thermometer readings.

It is an all pond solutions heater, it came as a package when I bought the tank along with the pump filters etc. It was fine in the hot weather cos the tank temp was 25 - 26. just dont want it too drop too much as uncomfy for fish. Tank temp has never gone lower than 24 or higher than 26 but when the light goes off at night dont want it to get too chily during the night, as the light throws out heat