Purpose for a ranco controller?

[RockStarFish]

I just got a ranco single stage and was wondering if it was just a on/off switch for your heater/chiller?

 

[Doahh]

Yes but the built in thermostat sucks in most heaters. Today mine failed. Im glad my Chiller was on the Ranco or I would have never noticed that the heater failed

 

[RockStarFish]

How do you plug the heater into it?

 

[Doahh]

they have a male edison plug and a female one.