Technical Instructions RDF20U Room Temperature Controller with LCD
Document Number 155-334 for Two-Pipe Fan Coil Units with Electric Heat
September 27, 2007
Page 8 Siemens Industry, Inc.
The QAH11.1 temperature sensor can be used as a return air temperature or
changeover sensor. The changeover sensor and the valves must be ordered
separately.
Two-way and Three-way
Zone Valves
The controller consists of two parts:
▪ Plastic housing which accommodates the electronics, the operating elements and
the built-in room temperature sensor
▪ Base
The housing engages in the base and is secured with two screws. The base carries the
screw terminals. The DIP switches are located at the rear of the housing.
Setting and Operating
Elements
Figure 7. RDF20U Components.
Display of the room temperature, setpoints or control parameters
Symbol used when displaying the current room temperature
Cooling valve open
Fan on
Heating valve open
Buttons for adjusting the setpoints and the control parameters
Operating mode selector
(Standby “ ”, Heating or Cooling mode with manual selection of fan speed)