I'm using this unit to control a dumb "portable" aircon in my bedroom. The AC unit has no temperature control, so it runs until I get too cold at night and turn it off. This Inkbird controller unit solves this much more cheaply than spending $400+ on a new AC when the one I have works quite adequately. Come winter, I will probably try it on my convection heater which has a mechanical temp sensor with a much wider on/off temperature cycle. My main criticism is that the "set" action should be emphasised in the instructions... "PRESS SET BUTTON FOR 3 SECONDS TO SAVE PARAMETERS" IN BOLD CAPS! Five Stars!