Checking The Combustion Chamber Pressure Limiter - Viessmann Vitocrossal 100 Series Service Instructions For Contractors

Commissioning, inspection, maintenance
Setting the maximum heating output
Weather-compensated control unit
Service menu
1. Press OK and simultaneously for approx. 4 s.
å
2. "Service functions"
3. "Max. output"
4. "Change?" Select "Yes".
A value is shown on the display (e.g. "85"). In the
delivered condition, this value is 100 % of the rated
heating output.
5. Set the required value.

Checking the combustion chamber pressure limiter

The combustion chamber pressure limiter responds in
the event of deflagration, blocks the burner and pre-
vents flue gas escaping if the flue system is damaged.
Fig. 5
A Reset button
Connection hose
B
Plug-in connection
C
4
2
3
Fig. 6
14
A
B
C
1
(cont.)
Constant temperature control unit
Service menu
1. Press OK and simultaneously for approx. 4 s.
å
2. Select " 3 " using . Confirm with OK.
Ú
The display shows "FL" and "ON" flashes.
3. Confirm with OK.
4. The display shows the set heating output (e.g. "85")
and " ". In the delivered condition, this value is
A
100 % of the rated heating output.
5. Set the required value. Confirm with OK.
Check connection hose
■
undamaged; replace if necessary.
■ Check whether the combustion chamber pressure
limiter has responded:
Measure the resistance across terminals 1 and 3. If
the resistance is > 0 , the pressure limiter has
Ω
responded.
If the combustion chamber pressure limiter has
responded, check the following components and
replace if necessary:
■ Electrodes
Burner gauze assembly
■
Ignition transformer and ignition cables
■
Check the flue system for damage and leaks.
■
Check the combustion chamber pressure limiter is
working properly using a pressure tester. Switching
point 100 10 mbar. If the value measured differs
±
from this, replace the combustion chamber pressure
limiter.
!
Please note
Incorrect installation or installing damaged
burner components can result in deflagration.
■ Check the combustion chamber pressure lim-
iter is working properly.
Check the burner components are undamaged
■
and correctly installed.
Danger
Faulty components and deflagration can cause
potentially fatal poisoning due to the escape of
carbon monoxide in the flue gas.
Observe the maintenance instructions.
is seated correctly and is
B