PEGASUS D
4.4 Troubleshooting
Diagnostics
The boiler is equipped with an advanced self-diagnosis system. In case of a boiler fault,
the display will flash together with the fault symbol (detail 22 - fig. 1) indicating the fault
code.
There are faults that cause permanent shutdown (marked with the letter "A"): to restore
operation just press the RESET button (detail 8 - fig. 1) for 1 second or RESET on the
optional remote timer control if installed; if the boiler fails to start, it is necessary to firstly
eliminate the fault.
Other faults (marked with the letter "F") cause temporary shutdowns that are automati-
cally reset as soon as the value returns within the boiler's normal working range.
Table. 2 - List of faults
Code
Fault
Possible cause
fault
No gas
Detection/ignition electrode
A01
No burner ignition
fault
Defective gas valve
Ignition power too low
Electrode fault
Flame present signal
A02
with burner off
Card trouble
Heating sensor damaged
Over-temperature pro-
toA03
No water circulation in the
tection trips
system
Air in the system
Fume thermostat contact
Fume thermostat acti-
open
vated (after activation of
F04
the fume thermostat,
Wiring disconnected
boiler operation is pre-
Flue not correctly sized or
vented for 20 minutes)
obstructed
Low pressure in the gas sys-
tem
No flame after the igni-
A06
tion phase
Burner minimum pressure
setting
Sensor damaged
F10
Delivery 1 sensor fault
Wiring shorted
Wiring disconnected
Sensor damaged
F14
Delivery 2 sensor fault
Wiring shorted
Wiring disconnected
Supply voltage under
F34
Electric mains trouble
170V.
Irregular mains fre-
F35
Electric mains trouble
quency
System empty
Incorrect system water
F37
Water pressure switch not
pressure
connected or damaged
Probe damaged or wiring
shorted
F39
External sensor fault
Sensor disconnected after
activating the sliding tem-
perature
Incorrect system water
F40
Pressure too high
pressure
Delivery sensor discon-
A41
Sensor positioning
nected from the pipe
F42
Heating sensor fault
Sensor damaged
System water pressure
F47
Wiring disconnected
sensor fault
Gas valve wiring fault
A48
Gas valve fault
Defective gas valve
Card trouble
Gas valve wiring fault
A49
Gas valve fault
Defective gas valve
Card trouble
Recommended cure
Check the regular gas flow to the boiler and
that the air has been eliminated from the
pipes
Check the wiring of the electrode and that it is
correctly positioned and free of any deposits
Check the gas valve and replace it if neces-
sary
Adjust the ignition power
Check the ionisation electrode wiring
Check the card
Check the correct positioning and operation
of the heating sensor
Check the circulator
Vent the system
Check the thermostat
Check the wiring
Replace the flue
Check the gas pressure
Check the pressures
Check the wiring or replace the sensor
Check the wiring or replace the sensor
Check the electrical system
Check the electrical system
Fill the system
Check the sensor
Check the wiring or change the sensor
Reconnect the external probe or disable the
sliding temperature
Check the system
Check the safety valve
Check the expansion tank
Check the correct positioning and operation
of the heating sensor
Change the sensor
Check the wiring
Check the wiring
Replace the gas valve
Replace the card
Check the wiring
Replace the gas valve
Replace the card
cod. 3540U171 - 06/2012 (Rev. 00)
5. TECHNICAL DATA AND CHARACTERISTICS
5.1 Dimensions, couplings and main components
400
246
44
275
273
Ø111
10
126
109
7
11
37
112
fig. 22 - Dimensions and connections model PEGASUS D 23
500
44
275
273
a4
126
11
B
fig. 23 - Dimensions and connections model PEGASUS D 32 and PEGASUS D 45
7
Gas inlet
10
System delivery
11
System return
44
Gas valve
126
Fume thermostat
246
Pressure transducer
273
Pilot light unit
275
Heating system drain cock
615
70
10
7
615
80
246
10
7
10
A
7
A
B
C
Pegasus D 30
116
119
47
Pegasus D 40
73
76
36
C
EN
44
275
44
275
a4
Ø
131
151
Ø
33