Vaillant ecoTEC plus Installation And Maintenance Instructions Manual page 33

restrictor). The colour of the gas restrictor must match
the colour of the coding resistor on the PCB.
9. Insert the gas restrictor for the gas group in question
into the new Venturi (yellow: G20 natural gas, grey:
Liquid gas).
10. When inserting the gas restrictor, ensure that the gas
restrictor is correctly aligned using the indicated pos-
ition marks on the upper side of the Venturi and also
the positioning pins (5) on the underside of the gas re-
strictor.
11. Refit the components in the reverse order. Use new
seals for this.
12. After installing the new Venturi, carry out a gas ratio
setting. (→ Page 25)
13. If you cannot adjust the CO2 content, the gas restrictor
has been damaged during installation. In this case,
replace the gas restrictor with an appropriate spare
part.
14. Perform a gas family check. (→ Page 21)
9.6.5 Replacing the heat exchanger
1. Drain the product. (→ Page 39)
2. Remove the compact thermal module. (→ Page 36)
3. Detach the condensate drain hose from the heat ex-
changer.
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2
3
4. Remove the clamps (2) and (3) from the flow connec-
tion and the return connection.
5. Detach the flow connection.
6. Detach the return connection.
7. Remove two screws (1) on each of the two retainers.
0020209593_01 ecoTEC plus Installation and maintenance instructions
8. Remove the lower three screws (2) on the rear section
of the retainer.
9. Swing the retainer to the side around the top screw (1).
10. Pull the heat exchanger downwards and to the right,
and remove it from the product.
11. Install the new heat exchanger in reverse order.
12. Replace the seals.
Note
Instead of grease, use only water or com-
mercially available soft soap to aid installa-
tion.
13. Insert the flow and return connections into the heat
exchanger as far as they will go.
14. Make sure that the brackets are seated correctly on the
flow and return connections.
15. Install the compact thermal module. (→ Page 38)
16. Fill and purge the product and, if necessary, the heating
installation. (→ Page 24)
9.6.6 Replacing the expansion vessel on the heat
generator
1. Drain the product. (→ Page 39)
2. Undo the screwed connection (4).
3. Remove both screws (1) on the support plate (2).
4. Remove the support plate (2).
Troubleshooting 9
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