Connection Of The Domestic Hot Water Sensor; Antifreeze Protection - DeDietrich MCR 24 Technical Instructions

4 Connection of the domestic hot water sensor

: Existing bridge
: Connecting the tank sensor

5 Antifreeze protection

: Existing bridge
: Cable BUS: AD 221 or AD 222 or Thermostat ON/OFF
MCR boilers must be installed in a frost-free environment
If the temperature of the central heating water in the boiler falls too
much, the integrated protection device switches itself on:
- If the water temperature is lower than 7°C, the circulating pump is
activated,
- If the water temperature is lower than 3°C, the boiler is activated,
08/06/06 - 300008460-001-B
If an external domestic hot water tank is used with the MCR boiler,
the probe without power from the domestic hot water tank can be
connected to connectors 3 and 4 of terminal block X9.
The control unit automatically detects the presence of an external
sensor.
- When the water temperature is above 10 °C, the boiler is switched
off and the circulation pump runs for another 15 minutes.
If a room thermostat, connected via connectors 7 and 8, is
activated, the boiler will operate permanently until it
reaches the outlet setting point.
MCR 24, 24/28 MI, 30/35 MI, 34/39 MI
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