REMEHA Avanta Plus 24s, Installation And Service Manual

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X9
Terminal
Block X9
DHW sensor (red band) or volt free thermostat (make on temp fall)
Remove existing link to use this function
1
2
3
4
5
6
7
8
Exist
links
X9
Terminal
Block X9
Modulating - using Open Therm control
eg: Honeywell Chronotherm or Celcia 20
On / Off - using simple volt free switching control
1
2
3
4
5
6
7
8
Exist
links
2.7.6 Connecting the DHW sensor/thermostat
LT.AL.W7H.000.031
• If an external DHW calorifier is being used with the Avanta
Plus system boiler a volt-free DHW control sensor or ther-
mostat can be connected to connectors 3 and 4 of the X9
terminal strip after removing the existing link. The control
will automatically detect whether a sensor or a thermostat
has been connected.
2.7.7 Connecting a frost thermostat
The boiler must be installed in a frost-free area to prevent the
condensate drain from freezing. However if the temperature of
the CH water in the boiler drops too low, the integrated boiler
protection device is activated as follows:
- at a water temperature below 7°C: the circulation pump is
switched on;
- at a water temperature below 3°C: the boiler is switched on;
- when the water temperature is above 10°C: the boiler is
switched off and the circulation pump runs for another 15
minutes.
o
•
A frost thermostat should preferably be installed in rooms
with a high frost risk.
•
Connect the frost thermostat in parallel to the room thermo
stat - connectors 7 and 8 of the X9 terminal strip (remove
existing link between connectors 7 and 8 before use).
m
• This function is a protection device for the boiler only, not
for the system or building fabric.
• If a frost thermostat or a modulating room control,
connected across connectors 7 and 8 is activated, the
boiler will operate continuously to achieve the flow set point.
• If the Celcia 20 control has been fitted, with an outside
sensor the boiler and building fabric will be protected.
See the installation documentation supplied with the control.