10.3.11 Removing Limescale - Baxi 224 Combi 2 Installation And Service Manual

Fig.75 Water unit parts

10.3.11 Removing limescale

The domestic water circuit can be cleaned after removing the water-water
heat exchanger from its seat, by unscrewing the two front screws (A).
For the cleaning operations, you must:
Disconnect the power supply to the boiler.
Cut off the gas supply to the boiler.
Close the heating system return and flow cocks.
Empty the water contained in the heating circuit by opening the cock (E).
Close the domestic water inlet cock.
Empty the water from the domestic water circuit by opening a user cock.
Remove the exchanger by unscrewing the two screws (A).
Clean the plate heat exchanger with a descaling product (e.g. formic or
citric acid with a pH value of around 3). After cleaning, rinse thoroughly
under running water.
To re-assemble, perform the above actions in reverse order.
Caution
The maximum tightening torque for the two fastening screws (A)
for the plate heat exchanger is 4 Nm.
For more information, see
Water treatment, page 19
10 Maintenance
Combi 2
69