Function Sequence And Possible Faults - Viessmann Vitodens 100-W B1HF Series Installation And Service Instructions Manual

Checking the static pressure and supply pressure
Supply pressure (flow pressure)
For natural gas
< 20 mbar (2.0 kPa)
20 - 25 mbar (2.0 -
2.5 kPa)
> 25 mbar (2.5 kPa)

Function sequence and possible faults

Control unit issues a heat
demand
Yes
Fan starts
Yes
Ignition
Yes
Gas solenoid valve opens
Yes
Ionisation current builds
Yes
Burner in operation
For LPG
< 50 mbar (5.0 kPa)
50 - 57.5 mbar (5.0 -
5.75 kPa)
> 57.5 mbar (5.75 kPa)
Display
No
No
Fault 59, 457
No Fault 359
No
Fault 357
No Fault 369, 380
No
Shuts down below the set
boiler water temperature and
restarts immediately.
Commissioning, inspection, maintenance
(cont.)
Measures
Do not start the boiler. Notify the gas supply utility or
LPG supplier.
Start the boiler.
Install a separate gas pressure governor upstream of
the system. Set the pre-charge pressure to 20 mbar
(2.0 kPa) for natural gas and 50 mbar (5.0 kPa) for
LPG. Notify the gas supply utility or LPG supplier.
Measure
Increase set value. Ensure
heat transfer.
Check the fan connecting ca-
bles. Check the fan power
supply.
Check ignition module (con-
trol voltage 230 V across
plug "X1/54" terminals "L"
and "N" on the HBMU).
Check the gas supply.
Check the gas supply pres-
sure.
Check distance of ionisation
electrode on burner gauze
assembly.
Purge the gas line.
Check the flue system for
tightness (flue gas recircula-
tion). Check gas flow pres-
sure.
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