Installation and operating instruction
Oil condensing boiler WTC-OB 18-B
3 Product description
83311002 1/2018-03 La
12-132
3.3.4 Safety and monitoring functions
Flow sensor eSTB
The fuel supply is shut off and the fan and the pump run-on are activated if the tem-
perature exceeds 95 °C (
W12
). The appliance restarts automatically if the temperat-
ure drops below the target supply value for 1 minute.
The fuel supply is shut off and the fan and the pump run-on are activated if the tem-
perature exceeds 105 °C. The system goes to lockout (
F11
). This locking function
of the supply sensor replaces the water deficiency safety function in accordance
with EN 12828.
Flue gas sensor
The fuel supply will be switched off and the fan and pump run-on activated if the
flue gas temperature exceeds the values defined in parameter
33
(factory setting
120 °C) (
F13
). On proximity to the safety temperature stage 1 is started, at 5 K dif-
ference (115 °C) the burner shuts down (
W16
).
Differential temperature flow / return
The boiler is switched off if the difference between the supply temperature and re-
turn flow temperature exceeds a preset value (
W15
). The installation goes to lockout
after 30 warnings with (
F15
).
System pressure sensor
If the system pressure drops below the value of parameter
39
, a waring message
is issued (
W36
). If the system pressure drops below 0.5 bar, the appliance shuts
down (
F36
). If the pressure increases above 0.5 bar, the appliance automatically
restarts.
Combustion chamber pressure sensor
The appliance shuts down if the combustion chamber pressure exceeds the prede-
termined value (
W19
). The installation goes to lockout after 3 warnings with (
F19
).
When approaching the specified value, a service message appears in the display,
the spanner icon flashes intermittently (twice briefly, long pause).
Level switch
The level switch is used to monitor leakage from water and oil carrying components
in the appliance. If the termination well is filled with liquid, the burner shuts down
(
W25
).
