5.3.7
Frost protection combined with on/off thermostat
When an on/off thermostat is used, the pipes and radiators in a frost-
sensitive room can be protected by a frost thermostat. The radiator valve
in the frost-sensitive room must be open.
1. Place a frost thermostat (Tv) in a frost-sensitive room (e.g. a garage).
2. Connect the frost thermostat (Tv) and the on/off thermostat (Tk) in
parallel to the R-Bus terminals of the connector.
Warning
If a Remeha eTwist or OpenTherm thermostat is used, a frost
thermostat cannot be connected in parallel to the R-Bus terminals.
In this case, ensure frost protection of the central heating system
in combination with an outside sensor.
5.3.8
Frost protection combined with outdoor temperature
sensor
The central heating system can also be protected against frost in
combination with an outdoor temperature sensor. The radiator valve in the
frost-sensitive room must be open.
1. Connect the outdoor temperature sensor to the Tout terminals of the
connector.
The frost protection works as follows with an outdoor temperature sensor:
If the outdoor temperature is lower than -10 °C: heat demand from the
boiler.
If the outdoor temperature is higher than -10 °C: no heat demand from
the boiler.
Important
The outdoor temperature before the start of frost protection can be
changed with the AP080 parameter.
5.3.9
Connecting an outdoor temperature sensor
An outdoor temperature sensor (accessory) can be connected to the Tout
terminals of the connector. If the boiler is equipped with an on/off
thermostat, the temperature is controlled using the setpoint of the internal
heating curve (F). Various parameter settings can be used to change the
internal heating curve.
1. Connect the plug from the outdoor temperature sensor to the Tout
terminal.
5.3.10 Blocking input
The boiler has a blocking input (normally closed contact). This input
relates to the BL terminals of the connector.
If this contact is opened, the boiler will be blocked or locked out.
Change the function of the input by configuring the AP001 parameter.
Important
Remove the bridge if this input is used.
Only suitable for potential-free contacts.
Fig.26
to SCB-02
MW-2000921-01
Tv
Tk
0-10
Tout
+
-
0-10
Tdhw
Tflow
R-Bus
Fig.27
to SCB-02
MW-2000922-01
0-10
Tout
+
-
0-10
Tdhw
Tflow
R-Bus
Fig.28
to SCB-02
MW-2000922-01
0-10
Tout
+
-
0-10
Tdhw
Tflow
R-Bus
Fig.29
to CB-09
MW-2000873-01
Tout
BL
RL
R-Bus
-
+
PWM
5 Installation
24
MID _HMI T-control - Gas 120 ACE
7717201 - v03 - 25062019
