All slab-type radiant systems work best if you do not use an “on or off” strategy to control the temperature. Instead, use a modern, programmable, floor sensing control that turns the temperature down (called a “setback”) to a preset temperature when the floor is satisfied, but keeps residual heat in the slab to respond quickly when the floor starts to cool off. Each home is different, but start with a 5 degree F setback to see if the room responds the way you want. If not, you can adjust the floor temperature, setback temperature and lead time features of the programmable thermostat to get the performance you want. Try the SunTouch Programmable FloorStat and we think you will be very pleased. For smaller areas, say under 30 square feet, you might just want to install a non-programmable control and leave it on throughout the heating season.