Hydor Theo Heater 400w

[fapjat]

I am having problems with my heater...I think? The light continues to go on for about a minute then off for a minute. Is this due to slowly heating the tank or is there something wrong with it. I thought the the light should stay on until the temperature was achieved, but maybe not. Please help my water temperature was suffering from my old heater that I just replaced and I want to make sure the fish do not suffer more cold water.

 

[Rooster]

Sounds normal to me... water is surprisingly "linear" the heat will sit in levels unless disturbed.... so the heater WILL turn on/off until an equilibrium is achieved in the whole tank (providing there IS water movement...)

 

[smegforbrains]

The Hydor Theos will not just stay on until the water is up to temperature. They click on and off at regular intervals, a sort of PID control effect. This is a good thing IMO because the increase in temperature is more gradual. It also increases the life span of the heating element.