Code
Fault
Possible cause
fault
Probe damaged or wiring shorted Check the wiring or replace the sensor
F39
External probe fault
Probe disconnected after activat-
ing the sliding temperature
Delivery sensor or DHW sensor
A41
Sensor positioning
detached from the pipe
F42
Heating sensor fault
Sensor damaged
No H
2
F43
Exchanger protection trips.
Air in the system
Modulating Operator wiring discon-
nected
F50
Gas valve fault
Faulty gas valve
A51
Poor combustion fault
Inlet/exhaust flue obstruction
5. TECHNICAL DATA AND CHARACTERISTICS
Table. 9 - Key of figures cap. 5
5 Sealed chamber
7 Gas inlet
8 Domestic hot water outlet
9 Cold water inlet
10 System delivery
11 System return
14 Safety valve
16 Fan
19 Combustion chamber
20 Burner assembly
21 Main nozzle
22 Burner
26 Combustion chamber insulation
27 Copper exchanger for heating and hot water
28 Fume manifold
29 Fume outlet manifold
5.1 General view and main components
187
5
16
278
81
20
21
22
42
340
10
8
44
fig. 18 - General view
30
EN
Cure
Reconnect the external sensor or disa-
ble the sliding temperature
Check the correct positioning and
operation of the sensors
Replace the sensor
O system circulation
Check the circulating pump
Vent the system
Check the wiring
Check the gas valve and replace it if
necessary
Check the flue
32 Heating circulating pump
36 Automatic air vent
38 Flowswitch
42 DHW temperature sensor
44 Gas valve
56 Expansion tank
72 Room thermostat (not supplied)
74 System filling cock
81 Ignition and detection electrode
114 Water pressure switch
138 External probe
139 Room unit
187 Fume baffle
278 Double sensor (Safety + Heating)
340 Bypass pipe
29
7
38 9
74
11
32
cod. 3540V402 - Rev. 00 - 9
5.2 Plumbing diagrams
27
278
10
340
42
27
278
56
28
27
19
26
14
10
340
42
36
114
DOMIproject F 24 D
38
9
74
8
fig. 19 - Heating Circuit
38
9
74
8
fig. 20 - DHW Circuit
56
114
36
32
14
11
56
114
36
32
14
11