81
MYDENS
COSMOGAS
8 - MAINTENANCE
C
B
A
E
D
F
020002.01.025
Figure 61
8.9 - Checking the expansion tank
When not otherwise specified, refer to Figure 61.
1. - The expansion tank is positioned on the left side of the
appliance.
2. - Check the pre-fill pressure of the expansion tank. It
must be at 1 bar.
3. - If the pressure is lower, increase it;
4. - Convey the exhaust pipes “A” and “B” (Figure 73) to a
drain, using a rubber hose;
5. - Power up the appliance and open the gas supply;
6. - Switch on the appliance;
7. - Open the exhausts until the pressure on the appliance
display is “0”;
8. - Use pin “F” to pump air into the tank until it reaches
1 bar. At the same time, allow water to flow from
exhausts “A” and “B” (Figure 73);
9. - Close exhausts “A” and “B” (Figure 73);
10. - Restore the pressure in the central heating system
(section 7.2);
If the tank needs replacing, proceed as follows to remove it:
(refer to Figure 61);
1. - Empty the central heating circuit (section 8.19);
2. - Remove screws “B”;
3. - Loosen fitting “C”;
4. - Extract the expansion tank “D” towards the front;
5. - Replace the tank;
6. - Restore the pressure in the central heating system
(section 7.2);
7. - Restore the state of the appliance by reassembling
everything in the reverse order to that used for the
dismantling phases;
