Simply turn the unit to HEAT or COOL, set the fan in the AUTO (comes on with the unit) or ON (continuous duty), and set your desired temperature – that is it!  The thermostat will now maintain that set temperature until you turn it off or change the temperature.  Again, this item is ideal for folks looking for a simply controller and a slimmer wall mount design.  This can be a FREE alternative to your Programmable Thermosat upon purchase of any Mermaid Air System.  It can also be added later to any of our standard 24v control a/c systems (Not FX-1 Thermostat adaptable).