SOFT HEAT DRYER
Soft Heat was introduced on higher end KM dryers with the 1963 models. On the electric dryers they used two heating elements, one was 3600 watts and the 2nd was 2000 watts this was on the dryers with the perforated revolving drum back, then when they changed to the solid rear bulkhead dryer drums the wattage's were 4100Ws and 1500Ws both designs total 5600 watts. With this design when a load was started both elements were on full blast, but when the exhaust reached around 135 degrees the larger element would shut off. This would normally occur when the majority of the moisture in the clothes load was gone, the smaller element would stay on the the entire heating portion of the drying cycle. If there was still much moisture left in the clothes the small element would not be enough heat to maintain and the large element would cycle back on to speed drying the drying along. But if the clothing was nearly dry the small element would be enough to maintain the exhaust temperature and no big blast of heat would be needed to finish the drying operation. This system was not only more gentle but was also faster as the heat was never completely off as in every other dryer on the market.
The gas Soft Heat system was even more exciting as it had an electrically ignited modulating gas burner. The older style dryer drum used a full 37,000 BTU burner and the later style solid bulkhead drum used a 25,000 BTU burner. On these gas models the burner would light at the start of the drying cycle and the flame would not go off at all, but instead would gradually taper down in response to a temperature sensor mounted in the exhaust housing. This is just like when you make a large pot of soup on the stove top of your stove, you start with full heat to get it boiling but you keep turning the heat down as it gets going. These were the only gas dryers ever made for the home that had such an advanced system of heat control.
But back to Jasons dryer. Sears cheapened the Soft Heat system around 1970-71 [ I don't know the exact year and model maybe Gordon can fill us in on this ]. Jasons dryer says Soft Heat on the console just like most high end KM dryers of the day, but it has just a single 5600 watt element and a single exhaust thermostat. I really don't know how they justified calling it a Soft Heat dryer. So Jason rewired it to use the real dual element system with a 4100W and a 1500W dual element. He also added a heater box and an exhaust housing thermal fuses so the dryer will be as safe as a new clothes dryer. So now it is a real SH dryer, PS, I hope the Sears deliver man that delivered it was cute.