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5.1.2 Valve protection function
5.1.3 Antifreeze protection function
5.1.4 Dew point monitoring
During periods without valve activation (e. g. outside the heating period) all heating zones with logged-
in room control unit are activated in a cyclic way in order to avoid clogging of the valves.
Independent from the operating mode, every switching output is equipped with an antifreeze func-
tion. As soon as a previously set antifreeze temperature (5...10°C) is fallen short of, the valves of the
allocated heating zone are activated until this temperature is reached. The antifreeze temperature can
be set via the microSD card, via the software surface of the Ethernet variant or via the service level of the
RBG display (parameter 161).
If the installation is equipped with a dew point sensor (provided by the customer), the valves of all heat-
ing zones are closed if dewing is detected in order to avoid damages due to humidity.
The dew point sensor input is only used during cooling operation.
5.1.5 Safety temperature limiter
5.2 Emergency operation
If an optional safety temperature limiter is used, all valves are closed when a critical temperature is
exceeded in order to avoid damage to sensitive floor coverings.
If the base station is unable to establish a radio connection to the room control unit allocated to the heat-
ing zone after a set time has elapsed, emergency operation is activated automatically. In emergency
operation, the switching outputs at the base station are activated with a modified PWM cycle duration
(parameter 181) independent from the heating system in order to avoid complete cooling of the rooms
(in heating operation) or dewing (in cooling operation).
5.1 Protection functions
5.1.1 Pump protection function
The base station is equipped with many protection functions for avoiding damage to the overall system.
In order to avoid damage by longer standstill times, the pump is activated within pre-defined periods.
The LED “pump” lights up during these periods.
5 Protection functions and emergency operation
