Electronics Self-Test; Working On The Compact Thermal Module - Vaillant ecoTEC exclusive VC 156/5‑7 N-DE Installation And Maintenance Instructions Manual

Test
Display
programme
T.04 Check cylinder
charge pump
T.05 Check circula-
tion pump
T.06 Check external
pump
T.08 Checking the
burner
11.2

Electronics self-test

Menu → Installer level → Test programs → Electronics
self-test
You can use the electronics self-test to check the PCB.
11.3

Working on the compact thermal module

11.3.1 Removing the compact thermal module
Note
The compact thermal module consists of four
main components:
– Speed-regulated fan,
– Gas valve,
– Burner flange,
– Premix burner.
Danger!
Risk of death and risk of material damage
caused by hot flue gas.
The seal, insulating mat and self-locking nuts
on the burner flange must not be damaged.
Otherwise, hot flue gases may escape and
cause personal injury and material damage.
▶
Replace the seal each time you open the
burner flange.
▶
Replace the self-locking nuts on the
burner flange each time you open the
burner flange.
▶
If the insulating mat on the burner flange
or on the back wall of the heat exchanger
shows signs of damage, replace the insu-
lating mat.
1. Disconnect the product from the power supply.
2. Close the gas isolator cock.
3. Remove the front casing.
4. Tilt the electronics box forward.
0020186710_06 ecoTEC exclusive Installation and maintenance instructions
Action
Switch the cylinder charging
pump on and off.
Switch the circulation pump
on and off.
Switch the external pump on
and off.
Product starts up and
switches to minimum load.
The flow temperature is
shown in the display.
Inspection and maintenance 11
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).
1 2
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. Release the cable harness from the clip.
11. Unscrew the four nuts (1).
12. Remove the entire compact thermal module (5) from
the heat exchanger (4).
13. Check the burner and the heat exchanger for damage
and dirt.
14. If necessary, clean or replace the components accord-
ing to the following sections.
15. Fit a new burner flange seal.
16. 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.
1
2
7
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