10.3.3 Draining the heating system
It may be necessary to drain the central heating system if radiators need
to be replaced, if there is a major water leak or if there is a risk of freezing.
1. Open the valves on all the radiators connected to the system.
2. Shut down the boiler.
3. Wait approximately 10 minutes, until the radiators feel cold.
4. Connect a drain hose to the lowest draining point. Place the end of the
hose in a drain or at a place where drained pipe water will not cause
any damage.
5. Open the central heating system filling/draining valve. Drain the
installation.
Warning
The water may still be hot.
6. Close the drain valve when no more water comes from the draining
point.
10.3.4 Check the hydraulic pressure
1. Check the hydraulic pressure in the installation.
Caution
The hydraulic pressure must reach a minimum of 0.08 MPa (0.8
bar).
Important
If the hydraulic pressure is lower than 0.08 MPa (0.8 bar), the bar
symbol flashes.
2. Top up the heating system with water to increase the hydraulic
pressure.
Important
The recommended hydraulic pressure when cold is between 0.15
MPa (1.5 bar) and 0.2 MPa (2 bar).
For more information, see
Displaying the water pressure on the control panel, page 38
10.3.5 Topping up the installation with water
1. Open the valves on all radiators connected to the heating system.
2. Set the room thermostat to as low a temperature as possible.
3. Put the boiler in shut-down/frost protection mode.
4. Open the fill valve.
5. Close the filling valve when the pressure gauge shows a pressure of
0.15 MPa (1.5 bar).
6. Put the boiler in heating mode.
Fig.63
MW-2000561-1
5
3
2
1
2
3
4
1
4
10 Maintenance
78
MID _HMI T-control - Gas 120 ACE
7717201 - v03 - 25062019
