Yea thanks Ray. I spoke to Johnny this morning and he explained that to me.

Ahh, cool. Thanks

Sorry. mine was 300w analog dial.

But I bought it against bad reviews. And it was a mistake.

I've not used this particular heater by finnex.

I've owned 2 or 3 Finnex heaters and all of them had an end come off within two years.
I'll not be buying another one.
They looked good though (before the end popped off and left exposed wires in the sump) and I controlled the temperature through my Profilux controller.