Buy thermostat fan

The Duct Stat automatically turns an attached duct booster (sold separately) on when the flow of heated air is sensed (in heat mode) or the flow of cold air is sensed in (cool mode). Automatically turns the duct booster off when the flow of air stops. Installs on the outside of the duct downstream of the duct booster. The Duct Stat must be manually switched between heat/cool modes in the winter and in the summer. Automatically senses airflow and turns thermostat fan ON/OFF Installs in minutes Works with most duct booster fans saves energy and money most electric hot water heaters have two thermostats, one near the top of the tank and one near the bottom, and are covered by removable metal cover plates. The Honeywell digital thermostats are pressed firmly against the bare metal wall of the hot water heaters tank. The top replacing thermostat usually has a high limit thermostat switch that will trip if the water gets too hot.  When it trips it shuts off the electricity to both the upper and lower heating elements. To reset the high limit switch there is usually a red button that you must press.  When the upper limit switch trips it is often an indication that something else has gone wrong with the heater. The Honeywell digital thermostat is not only attractive and accurate, but its ease of use can't be beat. Setting the desired temperature is as easy as pushing the up or down button. Additionally, three separate temperatures, day, night and vacation, can be configured so that your house can be quickly set to any of these temperatures with the press of a single button.