Vaillant ecoTEC plus Installation And Maintenance Instructions Manual page 32

9 Troubleshooting
5
4
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1. Remove the air intake pipe.
2. Remove the three plugs from the gas valve (2).
3. Remove the plug from the sensor on the Venturi (1) by
pushing in the latching lug.
4. Unscrew the two cap nuts (5) and (4) on the gas valve.
Use an open-ended spanner to counterhold the oppos-
ite side of the gas valve (4) and (5) when unscrewing.
5. Either remove the unit comprising the fan with gas valve
(Replacing the fan (→ Page 31)), or use an offset screw-
driver or Torx T20 socket to unscrew the fixing screw of
gas valve (3) from the retainer.
Note
The screw in the gas valve retainer secures
the gas valve against turning and must be
screwed back in once the gas valve has
been replaced.
6. Remove the gas valve from the retainer.
7. Reinstall the new gas valve in the reverse order. Use
new seals for this.
8. When tightening the cap nuts on the gas valve, use an
open-ended spanner to counterhold the opposite side of
the gas valve (4) and (5).
9. After installing the new gas valve, perform a leak-tight-
ness test (→ Page 27), gas family check (→ Page 21)
and gas ratio setting (→ Page 25).
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9.6.4 Replacing the Venturi
1
2
1. Remove the air intake pipe.
2. Remove the plug from the sensor on the Venturi (1) by
pushing in the latching lug.
3. Unscrew the cap nuts (3) of the gas connection pipe (2)
on the gas valve.
4. Remove the Venturi, including the gas connection pipe,
from the fan by turning the bayonet fitting on the Venturi
anti-clockwise as far as it goes and removing it straight
from the fan.
7
6
5
4
5. Remove the gas connection pipe (1) from the Venturi
(3) by removing the clamp (4) and pulling the gas con-
nection pipe out vertically. Dispose of the seal (7).
6. Pull the gas restrictor (6) straight off, and keep it for re-
use.
7. Check whether the Venturi is free of residue at the gas
inlet side.
Caution.
Risk of material damage to the product.
Lubricant can block function-related channels
in the Venturi.
▶
Do not use lubricant when installing the
gas restrictor.
8. Ensure that you use the correct gas restrictor (colour
coding and position of pins on the underside of the gas
Installation and maintenance instructions ecoTEC plus 0020209593_01
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