Vaillant ecoTEC plus VUI Series Installation And Maintenance Instructions Manual page 47

5. Unscrew the air intake pipe (1) from the upper retainer
and remove the air intake pipe from the intake stub, as
shown in the figure.
6. Unscrew the union nut from the gas valve assembly
(3).
7. Remove the two plugs from the gas valve assembly .
8. Remove the plug or, if necessary, the two plugs from
the fan motor (2) by pushing in the latching lug.
1
6
4
5
9. Remove the earth cable (6) from the ignition electrode
(4), the two plugs from the ignition transformer (5) and
the plug for the control electrode's cable (3).
10. Remove the four nuts from the burner flange (2).
11. Remove the entire compact thermal module from the
heat exchanger (1).
12. Check the burner and burner insulating mat for dam-
age. (→ Section 12.8.3)
13. Check the heat exchanger for damage.
Result:
Heat exchanger damaged
▶
Replace the heat exchanger. (→ Section 13.7.8)
14. Check the heat exchanger for dirt.
0020308121_04 Installation and maintenance instructions
A
B
C
3
2
3
4x
Result:
Heat exchanger dirty
▶
Clean the heat exchanger. (→ Section 12.8.2)
15. Check the insulating mat on the heat exchanger for
damage.
Result:
Insulating mat damaged
▶
1 Replace the insulating mat (→ Spare parts instruc-
tions for the heat exchanger insulating mat).
12.7.2 Installing the compact thermal module
2
6
4
5
1. Connect the compact thermal module to the heat ex-
changer (1).
2. Tighten the four new nuts in a cross-wise pattern until
the burner flange fits closely and uniformly onto the
mating surfaces.
–
Tightening torque: 6 Nm
3. Reconnect the earth cable (6) to the ignition electrode
(4). Reconnect the two plugs on the ignition trans-
former (5) and the plug for the control electrode's cable
(3).
2
3
1
4x
47