Johnlen Heater?

[fish12]

it says,"the heater must be placed horizontally while in use"? and im wondering why would it need to be plced in that certain position?


thank you

 

[fluttermoth]

Because hot water rises, like hot air.

If you have the heater vertically, the hot water rising up from the heating element makes the thermostat work much harder than it should, and can cause cold spots in the rest of the tank (as the thermostat 'thinks' the tank is warm enough when it's not).