Cleaning The Condensate Trap - Vaillant ecoTEC exclusive 843 Installation And Maintenance Instructions Manual

10. Unscrew the four nuts (7).
11. Remove the entire compact thermal module (2) from
the heat exchanger (1).
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.
10.3.2 Cleaning the heat exchanger
1. Protect the folded down electronics box against sprayed
water.
1
2. Never undo the four nuts on the stud bolt (1) or tighten
them.
3. Clean the heating coil (2) of the heat exchanger (3) us-
ing 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 water jet directly at
the insulating mat on the rear of the heat exchanger.
◁
The water flows out of the heat exchanger through
the condensate trap.
10.3.3 Checking the burner
1
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.
0020193968_03 ecoTEC exclusive Installation and maintenance instructions
Inspection and maintenance 10
10.3.4 Installing the compact thermal module
1. Connect the compact thermal module (2) to the heat
2
exchanger (1).
2. Tighten the four nuts (7) in a cross-wise pattern until the
3
burner flange fits closely and uniformly onto the mating
surfaces (if a torque spanner is available, set at 6 Nm).
3. Reconnect the plug (4) to the gas valve.
4. Reconnect the plug (5) for the earth line and the plug
(6) for the ignition line.
5. Reconnect all of the plugs to the fan motor (3).
6. Connect the gas line using a new seal. In the process,
secure the gas pipe against twisting.
7. Open the gas isolator cock.
8. Make sure that there are no leaks.
9. Check that the sealing ring in the air intake pipe is posi-
tioned correctly in the seal seat.
10. Reconnect the air intake pipe to the intake nozzle.
11. Secure the air intake pipe with the retaining screw.
12. Check the gas flow pressure. (→ Page 21)
10.4

Cleaning the condensate trap

1. Remove the lower section from the condensate trap.
2. Flush out the lower section with water.
3. Fill the lower section:
–
VUW 356/5-7: With water until around 10 mm below
the upper edge
–
VUW 436/5-7: With water until two-thirds full
4. Attach the lower section to the condensate trap.
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6
5
4
1
2
3
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