Vaillant ecoTEC exclusive 627 Installation And Maintenance Instructions Manual page 35

3
5. Unscrew the retaining screw (2) and remove the air
intake pipe (1) from the intake stub.
6. Unscrew the cap nut from the gas valve (3).
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3
4
5
6
7. Remove the ignition line plug (2) and the earth line plug
(3) from the ignition electrode.
8. Remove the plug (7) from the fan motor by pushing in
the latching lug.
9. Remove the two plugs from the gas valve (6).
10. Unscrew the four nuts (1).
11. Remove the entire compact thermal module (5) from
the heat exchanger (4).
12. Check the burner and the heat exchanger for damage
and dirt.
13. If necessary, clean or replace the components accord-
ing to the following sections.
14. Fit a new burner flange seal.
15. Check the insulating mat on the burner flange and on
the back wall of the heat exchanger. If you notice any
signs of damage, replace the relevant insulating mat.
0020193966_04 ecoTEC exclusive Installation and maintenance instructions
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12.8.2 Cleaning the heat exchanger
1. Protect the hinged down electronics box against spray-
ing water.
1 2
3
4
2. Never undo the four nuts on the stud bolt (1) or tighten
them.
3. Clean the spiral immersion heater (3) of the heat ex-
changer (4) using water or, if required, vinegar (to a
maximum of 5% acid). Allow the vinegar to act on the
heat exchanger for 20 minutes.
4. Rinse away any loose dirt with a sharp jet of water or
use a plastic brush. Do not point the jet of water dir-
ectly at the insulating mat (2) on the rear of the heat ex-
changer.
◁
The water flows out of the heat exchanger through
the condensate siphon.
12.8.3 Checking the burner
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2
3
1. Check the surface of the burner (1) for damage. If you
see any damage, replace the burner.
2. Fit a new burner flange seal (3).
3. Check the insulating mat (2) on the burner flange. If you
notice any signs of damage, replace the insulating mat.
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