If descaling of the plate exchanger is necessary, proceed as follows:
1. Ensure that the boiler is switched off.
2. Close the gas valve of the boiler.
3. Close the main water valve.
4. Drain the boiler:
- Open a domestic hot water tap to release the pressure and drain
any water from the circuit.
- Connect the filling loop to the heating return connection.
- Open the isolation tap and drain the circuit into a suitable
receptacle.
- When the water has stopped flowing, close all the isolation taps.
5. Unscrew the screw on the left-hand side of the heat exchanger.
6. Remove the plate heat exchanger by moving the left-hand side
forwards and tipping the right-hand side out of the bracket.
7. Clean the plate heat exchanger with a descaling product (citric
acid pH 3). To do this, a specific cleaning appliance is available
as an accessory. After cleaning, rinse thoroughly under running
water.
8.3.4.
Cleaning the domestic water cartridge
The plate heat exchanger should be removed in order to clean the
tap water cartridge. Then proceed as follows:
1. Dismantle the domestic water cartridge by rotating a screwdriver.
2. Remove the domestic water cartridge.
3. Clean or replace the domestic water cartridge if required.
4. Re-assemble all of the components.
8.3.5.
Replacement of the expansion vessel
The following procedures have to be carried out before the expansion
vessel can be replaced:
4
Close the gas valve of the boiler.
4
Close the main water valve.
4
Close the flow central heating pipe and the return central heating
pipe.
4
Drain the boiler.
R000741-A
6
5
4
3
Gas/Gaz
2
1
R000401-A
3
2
a
b
1
8. Checking and maintenance
Baxi MainEco Combi and System 24 - 28 - 35 / 18 - 24
60
02092014 - 7619497-02
