n
Connect frost protection
Frost protection in combination with on/off thermostat
If an on/off thermostat is used, it is advisable to protect any rooms
where there is risk of frost by using a frost thermostat. The radiator
valve in a room where there is a risk of frost must be open.
4
In rooms where there is a risk of frost, a frost thermostat (
Tv
)
should preferably be installed.
4
Connect the frost thermostat in parallel with an on/off room
thermostat (
Tk
) to the
On/off-OT
terminals of the connector.
When using a
OpenTherm
thermostat, a frost thermostat
cannot be connected in parallel to the
On/off-OT
terminals. Implement frost protection for the central heating
system in combination with an external sensor.
Frost protection in combination with an outside sensor
The central heating system can also be protected against frost in
combination with an outside sensor. The radiator valve in a room
where there is a risk of frost must be open. Connect the outside
sensor to the
Tout
terminals of the connector. The frost protection
functions as follows where an outside sensor is used:
4
At an outside temperature lower than -10°C (can be set with
parameter
p30
): the circulation pump switches on.
4
At an outside temperature higher than -10°C (can be set with
parameter
p30
): the circulation pump continues to run and then
switches off.
This is only possible with an iSense or qSense.
n
Operation signal and failure signal (Status)
The alarm or operation signal is selected using parameter
p40
.
4
If the boiler is operating, the operation signal can be switched via
a potential-free contact (maximum 230 VAC, 1 A) on the
No
and
C
terminals of the connector.
4
If the boiler locks out, the alarm can be transmitted via a potential-
free contact (maximum 230 VAC, 1 A) on the
Nc
and
C
terminals
of the connector.
4
The external 3-way valve (230 VAC, 1 A) can be used when
connecting an indirectly heated calorifier via a volt-free contact.
The neutral position of the three-way valve can be set using
parameter
p34
. The three-way valve is connected as follows:
-
Nc
= Central heating
-
No
= Domestic hot water
-
C
= Phase on
4
This is only possible with an iSense or qSense.
4
Status
connection can be used for standalone
condensate pump.
R000450-A
1
2
3
4
5
6
3
4
1
2
1
2
1
2
3
On/off
OT
Enable
+
-
+
-
CH
DHW
Status
Nc C No
Tout Tdhw BL
SCU
BUS
BUS
HMI
R000451-A
1
2
3
4
5
6
3
4
1
2
1
2
1
2
3
On/off
OT
Enable
+
-
+
-
CH
DHW
Status
Nc C No
Tout Tdhw BL
SCU
BUS
BUS
HMI
R000453-A
1
2
3
4
5
6
3
4
1
2
1
2
1
2
3
On/off
OT
Enable
+
-
+
-
CH
DHW
Status
Nc C No
Tout Tdhw BL
SCU
BUS
BUS
HMI
5. Installation
Baxi MainEco Combi and System 24 - 28 - 35 / 18 - 24
36
02092014 - 7619497-02
