Another object of this invention is to provide a device which automatically switches between thermal operating speed and circulation speed upon pre {HEAD ~ selected conditions} determined by {TAIL ~ a conventional thermostat} 
determined by
Another object of this invention is to provide a device which automatically switches between thermal operating speed and circulation speed upon pre { HEAD ~ selected conditions } determined by { TAIL ~ a conventional thermostat }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL