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T e c h n i c a l N o t e b o o k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T e c h n i c a l T r a i n i n g
Safety devices for fan flue boilers
Safety
Control device
Values
Action
Safety devices locking the appliance and requiring a RESET in the case of a fault
Overheating and
temperature limiting
Outgoing/return
heating NTC
97 °C => max. temperature
Fault displayed F20
T° increase more than 10 K/S.
Fault displayed F24
ΔT (outlet - return) > 35 K
Fault displayed F23
Flame control
Ignition and
ionisation
electrode
Up to 3 spark sequences separated by 7
seconds
Fault F28 if no ignition
Fault F29 if burner goes out
Gas
Gas safety valve
0V when shut down
24V then 16V in operation
Display of various faults depending
on origin
Air flow
Air flow switch
12 kW -> at 25°C : ON 13 Pa, OFF 10 Pa
23 kW -> at 25°C : ON 71 Pa, OFF 46 Pa
25 kW -> at 25°C : ON 80 Pa, OFF 68 Pa
30 kW -> at 25°C : ON 59 Pa, OFF 51 Pa
On = contact closed
Off = contact opened
Fault displayed F33
Safety devices not requiring a RESET after the fault clears
Antifreeze
Outlet NTC
7 °C --> immediate heating
Burner lit up to 35°C
Pump anti-blocking
Internal computer Activated for 30s if not activated for 24
hours
Activation without apparent demand
3-way valve
anti-blockage
Activated for 30s if not activated for 24
hours
Activation without apparent demand
Heating pressure
Pressure sensor
Triggered at 0.5 bar
Reset at 0.3 bar
Display
below 0.3 bar
display blinking between 0.3 and 0.5 bar
Heating valve
Opens at 3 bar
Evacuation of excess pressure
(display blinking below 2.5 bar)
Temperature safety
(ant-freezing / overheating)
Gas safety valve
(EVS)
Air flow switch
Flame control
3-way valve
anti-blockage
Water pressure sensor
Pressure relief valve
(3 bar)
Pump anti-block