RED COMPACT SLIM 15 Installation Manual page 40

7 - HYDRAULIC CONNECTION
• after starting up the boiler for the first time and bringing the system up to temperature, stop the pumps and repeat the air purging
procedure;
• leave the system to cool, and if necessary, restore the water pressure to 1 bar.
NOTE
In systems with a closed vessel, where possible, the water pressure in the heating system must not be lower than 1
bar when the system is at room temperature; if this is not the case, use the tap to fill the system.
This operation must be performed when the system is cool.
The pressure gauge on the system enables you to read the pressure in the circuit.
To fill the system, the hydraulic kit is equipped with a tab, with a stop valve, so that you can manually fill the heating system.
During this operation, any air in the system is released from the automatic vent valve located at the top of the body of the boiler.
To allow the valve to vent, loosen the side cap (see figure)
The filling pressure of the system WHEN COLD must be 1 bar.
Upon completion of this operation, always close the tap.
To access the vent valve, lift the central cover and loosen the side cap.
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PURGE VALVE WITH CAP