8.3.2.
Replacing the 3-way valve
If it becomes necessary to replace the 3-way valve, proceed as
follows:
1. Close the main water valve.
2. 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.
3. Open the protective cover for the fan at the top.
4. Disconnect the three-way valve cable from the automatic control
unit.
5. Unclip the locking clip that holds the 3-way valve.
6. Dismantle the 3-way valve by rotating a screwdriver.
7. Remove the 3-way valve.
8. To re-assemble, perform the above actions in reverse order.
CAUTION
Be careful of the positioning cams on the 3-way valve.
8.3.3.
Cleaning the plate heat exchanger
Depending on the water quality and the operating mode, limescale
deposits may form in the plate exchanger. As a general rule, a
periodic inspection, along with cleaning, if necessary, is sufficient.
The following factors may affect the periodicity:
4
Water hardness.
4
Composition of the limescale.
4
Number of hours’ operation of the boiler.
4
Draw-off rate.
4
Domestic hot water set point temperature.
R000400-A
4
3
6
5
7
2
1
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8. Checking and maintenance
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