Analogue Electronic Room Temperature controller for
underfl oor heating.
Operating and mounting instructions
General
Congratulations on choosing the new REHAU room controller. In
selecting the REHAU Star 20 you have chosen an analogue electronic
room temperature controller which off ers key advantages over conven-
tional mechanical products. This unique controller is easy to operate
using the conventional backlit adjusting dial. The illuminated dial gives
the extra function of displaying when room set point is achieved. It
also off ers you unique control simplicity for heating applications of all
types thanks to the high quality device electronics. This electronic
control system ensures that the set room temperature is maintained
and when required a time signal input automatically activates a
reduction in temperature (night setback).
Building regulations and the environment
REHAU have a commitment to assist building owners and occupiers
to reduce their carbon footprint, by reducing the energy used for
heating systems and hot water. One eff ective method is to burn fuel
when there is a demand for heat from the boiler, either for heating or
hot water. When this demand is satisfi ed, the boiler should switch off
again – it should not be able to fi re until a new demand is created by
REHAU STAR CONTROLS
STAR 20 -ANALOGUE ELECTRONIC ROOM CONTROLLER, ART NO: 206029
the controls. This is called Boiler Interlock and represents the mini-
mum standard required under the Building Regulations for new and
existing heating systems.
The following characteristics of the REHAU Star 20 guarantees you
precise, comfortable and energy saving operation of you room heating
system.
Technical characteristics
Pulse-Width-Modulation (PWM)
Underfl oor heating has the basic problem of Temperature overshoot.
i.e. the room continues to be heated even when the valve is closed
and the desired room temperature has been reached. The REHAU Star
20 solves this problem electronically and extremely eff ectively using
Pulse-Width-Modulation (PWM), It operates using a constant com-
parison of desired and actual temperature. The opening period of the
actuators is adjusted as to avoid over and under shoot, therefore
the actual is much closer using PWM to the desired setpoint tem-
perature. This achieves a more precise and comfortable control of the
desired set point desired temperature.
Please note:- if the REHAU Star 20 is used for radiators or
convection heating systems, the Pulse-Width-Modulation (PWM) can
be switched off (see basic settings section).
Valve protection feature
In order to ensure that the valves remain fully functional even after
long periods of no operation - i.e. in summer, the REHAU
controller is supplied with a switchable valve exercising operation.
This ensures that the valves remain functional by operating the
output each week. This valve protection feature can be deactivated if
required.
Temperature reduction (Night setback)
It is important to reduce energy and today we have the ability to
reduce the room temperature in times of inactive or no occupancy.
Industry research has shown that this can signifi cantly reduce the
energy required in a normal dwelling by up to 30%.
The REHAU Star 20 allows you to automatically reduce the room tem-
perature by 4K, without the need to adjust the room unit, based on a
Building Solutions
Automotive
Industry
