Checking The Gas Train Valves For Tightness - Viessmann Vitocrossal CRU 800 Service Instructions For Contractors

Closing the combustion chamber
Tighten the burner door screws diagonally to a torque
of 30 Nm.
Danger
Leaks from the burner door can result in poison-
ing through escaping gas.
Check the burner door for flue gas tightness,
e.g. with inspection mirror, gas sensor or ther-
mal image camera.
In the case of leaks, retighten diagonally to
40 Nm.
Check the flue gas tightness again.

Checking the gas train valves for tightness

A
Fig. 16
1. Close the gas shut-off valve.
2. Undo screw in test connector
the screw.
3. Connect the pressure gauge at test connector
4. Using the pressure gauge, carefully build a test
pressure of approx. 50 mbar (5 kPa).
B
. Do not remove
B
B
Commissioning, inspection, maintenance
(cont.)
5. Wait approx. 5 min for the temperature to level out.
Then observe the display on the pressure tester:
The gas train is gas-tight if the displayed pressure
does not drop by more than 1 mbar (0.1 kPa)
within a further 5 min.
Otherwise, replace the gas train.
.
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