Automatic, reflux control via solenoid valve arrangement. Reflux control is effected by an adjustable time switch,such as 6671-14 control, and a solenoid take-off plunger valve surrounded by 6590-10 electromagnetic coil. Reflux ratio is thus a time function and is independent of throughput. A supplied #7 Ace-Thred™ bushing accepts 6-7mm diameter temperature probes or thermometers. Equalizing arm 12/3 joints are supplied with 7669-03 clamps. Top and bottom joints are 14/20. Thermometer not included.