Ferroli PEGASUS F2 N 2S Troubleshooting guide

PEGASUS F2 N T
cast iron gas boiler for central heating
chaudière à gaz en fonte pour chauffage central
INSTRUCTIONS FOR USE, INSTALLATION AND MAINTENANCE
INSTRUCTIONS D‘UTILISATION D‘INSTALLATION ET D‘ENTRETIEN
cod. 3544705/2 - 01/2005

Pegasus F2 N T
2
Certification
TheCEmarkingdemonstratesthatFerroligas
units conform to the requirements contained
in the applicable European directives.
In particular, this unit complies with the
following EU directives:
• GasApplianceDirective90/396assimilated
with Italian Presidential Decree DPR
15.11.96 no. 661
• Efficiency Directive 92/42 assimilated with
Italian Presidential Decree DPR 15.11.96
no. 660
• Low Voltage Directive 73/23 (amended
by 93/68)
• Electromagnetic Compatibility Directive
89/336 (amended by 93/68) assimilated
with Italian Presidential Decree DPR
15.11.96 no. 615
This symbol indicates “Caution”
and is placed next to all safety
warnings. Strictly follow these
instructions in order to avoid
danger and damage to persons,
animals and things.
This symbols calls attention to a
note or important notice
• Carefully read the warnings in this
instruction booklet since they provide
important information on safe installa-
tion, use and maintenance.
• This instruction booklet is an integral
partoftheproductandmustbecarefully
kept by the user for future reference.
• If the unit is sold or transferred to
another owner or if it is to be moved,
always make sure that the booklet
accompanies the boiler so that it can
be consulted by the new owner and/or
installer.
• Installation and maintenance must
be carried out by professionally quali-
fied personnel, according to current
regulations and the manufacturer’s
instructions.
• Incorrect installation or poor mainte-
nance can cause damage or physical
injury. The manufacturer declines any
responsibility for damage caused by
errors in installation and use or by
failure to follow the manufacturer’s
instructions
• Before carrying out any cleaning or
maintenance operation, disconnect the
device from electrical power supply
using the switch and/or the special
cutoff devices.
• In case the unit breaks down and/or
functions poorly, deactivate it, do not
make any attempt to repair it or directly
intervene. Contact professionally quali-
fied personnel.
• Any repair/replacement of products
must only be carried out by qualified
professionalpersonnelusingexclusively
genuine parts. Failure to comply with
the above could affect the safety of
the unit.
• Yearly maintenance carried out by
qualified personnel is essential for
guaranteeing good operation of the
unit.
• This unit must only be used for the
purpose for which it was designed. Any
other use is considered improper and
therefore hazardous.
• After removing the packing, check the
integrity of the contents.
• Packing materials must not be left
within the reach of children as they are
potentially hazardous.
• In case of doubt do not use the unit,
and contact the supplier.

Pegasus F2 N T
3
1. Operating instructions............................................................................4
1.1 Introduction.............................................................................................................4
1.2 Control panel and main components .....................................................................4
1.3 Turning on and off...................................................................................................5
1.4 Adjustments............................................................................................................7
1.5 Maintenance............................................................................................................8
1.6 Trouble ....................................................................................................................8
2. Installation..............................................................................................9
2.1 General Instructions................................................................................................9
2.2 Place of installation.................................................................................................9
2.3 Plumbing connections.............................................................................................9
2.4 Gas connection .....................................................................................................10
2.5 Electrical Connections ..........................................................................................11
2.6 Connection to the flue..........................................................................................12
3. Service and maintenance......................................................................13
3.1 Adjustments..........................................................................................................13
3.2 System start-up.....................................................................................................16
3.3 Maintenance..........................................................................................................17
3.4 Troubleshooting ................................................................................................... 21
4 Technical characteristics and data .........................................................23
4.1 Dimensions and connections ................................................................................23
4.2 General view and main components ....................................................................24
4.3 Technical data table ..............................................................................................25
4.4 Diagrams ...............................................................................................................26
4.5 Wiring diagrams....................................................................................................27

4
Pegasus F2 N T
Fig. 1
1. OPERATING INSTRUCTIONS
1.1 Introduction
Dear Customer,
Thank you for choosing Pegasus F2 N T, a FERROLI floor-standing boiler featuring advanced
design, cutting-edge technology, high reliability and quality construction. Please read this manual
carefully and keep it for future reference.
Pegasus F2 N T is a high-efficiency heat generator for central heating running on natural or liquid
gas (configurable at the time of installation).
The boiler shell consists of cast-iron elements whose particular shape guarantees high exchange
efficiency under all operating conditions and an open-flue main burner equipped with a pilot
burner with piezoelectric ignition.
The boiler outfit moreover includes an automatic boiler air vent valve, control thermostat, safety
thermostat and fume thermostat.
1.2 Control panel and main components
To access the control panel, lift the front door.
Key
1Arrangement for thermostatic controller
2Boiler pressure/temperature gauge
3Fume thermostat cover
4Plugs
5Boiler control thermostat
60 - 1 - TEST switch
7Gas valve
8Piezoelectric igniter
9Pilot light unit
10 Inspection door
1243445 6
7
8
9
10
FRONT VIEW WITHOUT
FRONT PANEL

5
Pegasus F2 N T
1.3 Turning on and off
Opening the front panel
To open the front panel, see the sequence in fig. 2.
1
2
Fig. 2
Ignition with SIT 820 NOVA valve for models
51-68 (fig. 3)
Make sure the boiler switch is on “0”(part 6 fig. 1).
Turn the boiler control thermostat 5 (fig. 1) onto mini-
mum.
Open the gas cock ahead of the boiler.
Open the inspection door 10 of fig. 1.
Press control knob 1 of the gas valve and keep it pressed
on position “a”(fig. 3).
Ignite the pilot burner by repeatedly pressing the button
of the piezoelectric igniter 8 (fig. 1).
Once the pilot light is burning, keep the gas valve knob
pressed for approximately 15 to 20 seconds and then
slowly release it, checking that the pilot light stays lit. If
it goes out, wait for 30 seconds and repeat the ignition
operation.
Power up the boiler’s electric circuit and turn the boiler
switch onto “I”.
Turn the boiler control thermostat 5 (fig. 1) onto the
desired temperature (no less than 50°C).
At this point, the main burner will light and the boiler begins to function automatically.
Pilot Burner
Ignition
Main Burner
Ignition
Turning Off
SIT 820 NOVA VALVE
Fig. 3

6
Pegasus F2 N T
Ignition with HONEYWELL V4400C valve for models 85-102 (fig. 4)
Make sure the boiler switch is on “O”(part 6 fig. 1).
Turn the boiler control thermostat 5 (fig. 1) onto minimum.
Open the gas cock ahead of the boiler.
Open the inspection door 10 of fig. 1.
Press the gas valve ignition button “A”and keep it pressed.
Ignite the pilot burner by repeatedly pressing the button of the piezoelectric igniter 8 (fig. 1).
Once the pilot light is burning, keep the gas valve knob pressed for approximately 15 to 20 seconds
and then slowly release it, checking that the pilot light stays lit. If it goes out, wait for 30 seconds
and repeat the ignition operation.
Power up the boiler’s electric circuit and turn the boiler switch onto “1”.
Turn the boiler control thermostat 5 (fig. 1) onto the desired temperature (no less than 50°C).
At this point, the main burner will light and the boiler begins to function automatically.
HONEYWELL V4400C VALVE
Fig. 4
Key
1 Ignition button
2 Off button
In case of an electrical power failure while the boiler is working, the main burner will go out and
re-ignite automatically when power is restored.

7
Pegasus F2 N T
Turning the boiler off temporarily
To turn the boiler off for a short period of time, just cut off power to the unit (by turning the boiler switch
off). In this way, power is cut off to all the electric parts and only the pilot light stays on.
Turning the boiler off for an extended period
Turn knob 1 as shown in fig. 3 (on models 51-68), or press button 2 as shown in fig. 4 (on models
85-102). This shuts off the gas line to both the main burner and the pilot. Close the gas cock ahead
of the boiler and cut off power to the unit.
To avoid damage caused by freezing during long shutdowns in winter, it is advisable to drain all
water from the boiler and the system; or add a suitable antifreeze to the heating system.
The boiler switch 6 has 3 positions, “0-1-TEST”; the first two have the on-off function, the third
(unstable) must only be used for service and maintenance purposes.
1.4 Adjustments
System temperature adjustment
Turn knob 5 (fig. 1) clockwise to increase the heating water temperature, turn anticlockwise to decrease
it. The temperature can be varied from a minimum of 30°C to a maximum of 90°C. However, it is
advisable not to operate the boiler below 50°C.
Room temperature adjustment (with optional room thermostat)
Using the room thermostat, set the temperature desired in the rooms. Controlled by the room
thermostat, the boiler lights and delivers water to the system at the temperature set by the
boiler control thermostat 5 (Fig. 1). The generator turns off when the desired temperature in
the rooms is reached.
If the room thermostat is not installed the boiler will keep the system at the temperature set
by the boiler control thermostat.
Water system pressure adjustment
The filling pressure with system cold, read on boiler hydrometer (detail 2 in fig.1), must be about 1.0 bar.
If, during operation, the system pressure falls (caused by the evaporation of gas dissolved in the water) to
values below the minimum described above, the user must bring it back to the initial value by operating
the filling cock. At the end of the operation always close the filling cock.

8
Pegasus F2 N T
Before calling the assistance service, check that the problem is not due to there being no
gas or electricity.
1.5 Maintenance
Theusermust have the heatingsystemservicedbyqualified personnel at leastonceayearand combustion
checked at least every two years. Consult chapter 3.3 of this manual for more information.
The boiler casing, panel and aesthetic parts can be cleaned with a soft damp cloth, possibly soaked in
soapy water. Do not use any abrasive detergents and solvents.
1.6 Anomalies
Listed below are the anomalies that can be caused by simple, user-solvable problems.
Symbol Fault Cure
Boiler shutdown due to low pressure
(only if a pressure switch is installed
on the system)
Fill the system to 1-1.5 bar cold by means of the system filling cock.
Close the cock after use.
Boiler shutdown due to insufficient
e acuation of fumes Unscrew the fume thermostat co er and press the button below. In case of repeated shutdowns, contact the nearest assistance centre.

Pegasus F2 N T
9
2. INSTALLATION
2.1 General Instructions
This device must only be used for the purpose for which it is specially designed. This unit
is designed to heat water to a temperature below boiling point at atmospheric pressure
and must be connected to a heating system and/or a water supply system for domestic
use, compatible with its performance, characteristics and its heating capacity. Any other
use is considered improper.
THE BOILER MUST ONLY BE INSTALLED BY QUALIFIED PERSONNEL, IN ACCORDANCE WITH ALL
THE INSTRUCTIONS GIVEN IN THIS TECHNICAL MANUAL, THE PROVISIONS OF CURRENT LAW,
ANY LOCAL REGULATIONS AND THE RULES OF PROPER WORKMANSHIP.
Incorrect installation can cause damage or physical injury for which the manufacturer declines
any responsibility.
2.2 Place of installation
This unit is an “open chamber”type and can only be installed and operated in permanently ventilated
rooms. An insufficient flow of combustion air to the boiler will affect its normal operation and fume
evacuation. Also, the fumes forming under these conditions (oxides) are extremely harmful to health
if dispersed in the domestic environment.
Therefore the place of installation must be free of dust, flammable materials or objects or corrosive
gases. The room must be dry and not subject to freezing.
When positioning the boiler, leave sufficient space around it for normal maintenance activities.
2.3 Plumbing connections
The heating capacity of the unit should be previously established by calculating the building’s heat
requirement according to current regulations. For good operation and long life of the boiler, the
plumbing system must be well proportioned and always complete with all those accessories that
guarantee regular operation and running.
If the delivery and return pipes follow a path where air pockets could form in certain places, it is
advisable to install vent valves at these points. Also, install a discharge device at the lowest point in
the system to allow its complete emptying.
If the boiler is installed at a lower level than the system, it is advisable to provide a flow-stop valve to
prevent the natural circulation of system water.
The temperature drop between the delivery manifold and the return to the boiler should not
exceed 20°C.
Do not use the water system pipes to earth electrical appliances.
Before installation, carefully wash all the pipes of the system to remove residues or impurities that
could affect the unit’s good working.
Make the connections to the corresponding connections as shown in Fig. 5.

Pegasus F2 N T
10
It is advisable to install on-off valves between the boiler and
heating system allowing the boiler to be isolated from the
system if necessary.
Make the boiler connection in such a way that its internal
pipes are free of stress.
Fig. 5
B
Characteristics of the water system
In the presence of water harder than 25°Fr, we recommend the use of suitably conditioned water in order
to avoid possible scaling in the boiler, caused by hard water, or corrosion produced by aggressive water.
It should be remembered that, because of its low thermal conductivity, even scaling of just a few mm thick
causes significant overheating of the boiler walls with consequent serious problems.
Water treatment is indispensable in the case of very large systems (containing large amounts of water) or
with frequent introduction of replenishing water in the system. If partial or total emptying of the system
becomes necessary under these conditions, it is advisable to refill it with treated water.
Filling boiler and system
The filling pressure with system cold system must be about 1 bar. If, during operation, the system
pressure falls (caused by evaporation of gas dissolved in the water) to a value below the minimum
described above, the user must bring it back to the initial value. For correct operation of the boiler,
when hot, its pressure must be about 1.5÷2 bar.
2.4 Gas connection
Before making the connection, ensure that the unit is arranged for operation with the type of
fuel available and carefully clean all the pipes of the gas system to remove any residues that
could affect good functioning of the boiler.
The gas must be connected to the relative connector (see Fig. 5) in conformity with current standards,
with rigid metal pipes or with continuous flexible s/steel wall tubing, placing a gas cock between the
system and the boiler. Make sure that all the gas connections are tight.
The capacity of the gas meter must be sufficient for the simultaneous use of all equipment connected
to it. The diameter of the gas pipe leaving the boiler does not determine the diameter of the
pipe between the unit and the meter; it must be chosen according to its length and loss of head,
in conformity with current standards.
Do not use the gas pipes to earth electrical appliances.
Pegasus F2 N 51 T
Pegasus F2 N 68 T
Pegasus F2 N 85 T
Pegasus F2 N 102 T
550
640
720
800
B
180
180
200
200
C
43
46
44
42
D
35
38
36
34
E
Type and model
3/4
3/4
3/4
3/4
a3
Gas inlet
1 1/2
1 1/2
1 1/2
1 1/2
a2
eating
delivery
1 1/2
1 1/2
1 1/2
1 1/2
a1
eating
return
Rear view

Pegasus F2 N T
11
2.5 Electrical Connections
Connection to the electrical grid
The boiler must be connected to a single-phase, 230 Volt-50 Hz electric line.
The unit’s electrical safety is only guaranteed when correctly connected to an efficient earthing
system executed according to current safety standards. Have the efficiency and suitability of
the earthing system checked by professionally qualified personnel. The manufacturer is not
responsible for any damage caused by failure to earth the system. Also make sure that the
electrical system is adequate for the maximum power absorbed by the unit, as specified on
the boiler dataplate, in particular ensuring that the section of the system’s cables is suitable
for the power absorbed by the unit.
The boiler is prewired and supplied with a connector located inside the control panel, arranged for
connection to an electronic thermostatic controller (see wiring diagrams in paragraph 4.5). In addition,
it is equipped with a three-pole cable for connection to the electricity line. The connections to the grid
must be made with a permanent connection and equipped with a bipolar switch whose contacts have
a minimum opening of at least 3 mm, interposing fuses of max. 3A between the boiler and the line. It
is important to respect the polarities (LINE: brown wire / NEUTRAL: blue wire / EARTH: yellow-green
wire) in making connections to the electrical line.
Access to the electrical terminal board and internal components of the
control panel
To access the electrical components inside the control panel, follow the sequence in fig. 6 - 7 - 8 - 9.
The layout of the terminals for the various connections is given in the wiring diagrams in the
technical data chapter.
Fig. 6 - Unscrew the 2 self-tapped screws holding
the boiler cover.
Fig. 7 - Lift by pressing upwards and take off the cover
that is held at the sides of the boiler by pins.
Fig. 8 - Unscrew and take out the two screws and both
plates holding the control panel.
Fig. 9 - Turn the control panel forwards.

Pegasus F2 N T
12
2.6 Connection to the flue
The diameter of the flue connection pipe must not be less than that of the connection on the
anti-backflow device. Starting from the anti-backflow device it must have a vertical section at least
50 cm long. Current standards must be complied with regarding the dimensioning and installation
of the flues and connection pipe.
The diameters of the anti-backflow device collars are given in the table of fig. 5.
Anyadditionalsensitiveelements of the system’scontrol
and safety devices, temperature sensor, pressure
switch, thermostat bulb, etc., must be located on the
delivery pipe within 40 cm. of the rear wall of the boiler
casing (see Fig. 10).
max. 40 cm
System deli ery
System return
Fig. 10

Pegasus F2 N T
13
3. SERVICE AND MAINTENANCE
3.1 Adjustments
All adjustment and conversion operations must be carried out by Qualified Personnel.
The manufacturer declines any responsibility for damage or physical injury caused by unqualified and
unauthorized persons tampering with the device.
Adjusting the burner gas pressure
Pegasus F2 N T boilers are made to burn natural gas. The pressure setting and test are
performed in the factory.
However, as there may be changes in supply pressure, at the time of the first ignition it will be
necessary to check and perhaps adjust the pressure at the nozzles, observing the values given in
the technical data chart in paragraph 4.3.
The operations for adjusting the pressure are performed with the boiler working, using the pressure
control on the gas valves (see fig. 11a - 11b).
Preliminary operations:
1Ignite the boiler and turn the control thermostat knob onto minimum.
2Connect a pressure gauge to the pressure point on the gas manifold pipe of the burner assembly
(see part 15 in Fig. 19).
3Take off the cover protecting the pressure regulator 6 of fig. 11a - 11b.
Gas conversion and pressure control with the “SIT 820 NOVA”valve
The main burner pressure setting is performed using screw 2 (fig. 11a) that is turned clockwise to
increase the pressure and anticlockwise to decrease it.
The pilot light adjustment is made without using instruments, watching to see that the flame
correctly envelops the thermocouple without burning too much gas. To adjust this flame, turn
screw 5 (fig. 11a).
To convertthe boiler fromnaturalgas to liquidgas, besides changingthe nozzles itis necessary,taking due
care, to screw the pressure control screw 2 fully in and change the pilot burner nozzle.
Gas conversion and pressure control with the “HONEYWELL V4400C”valve
The main burner pressure setting is performed using screw 2 (fig. 11b) that is turned clockwise to
increase the pressure and anticlockwise to decrease it.
The pilot light adjustment is made without using instruments, watching to see that the flame
correctly envelops the thermocouple without burning too much gas. To adjust this flame, turn
screw 5 (fig. 11b).
To convertthe boiler fromnaturalgas to liquidgas, besides changingthe nozzles itis necessary,taking due
care, to screw the pressure control screw 2 fully in and change the pilot burner nozzle.
The full kit for conversion to liquid gas (G30 - G31) is only supplied on request.
The gas pressures measured at the burner gas manifold should be read at least 30 seconds after
making the adjustments, i.e. when the flame has stabilized.
On completing the adjustment operations, turn the burner on and off 2 - 3 times with the
adjustment thermostat and check that the pressure values are the ones you have just set; if this is
not so, you need to make another adjustment to bring the pressures to the right values.

Pegasus F2 N T
14
Fig. 11a
Changing the main nozzles and pilot light nozzle
To change the main and pilot nozzles, proceed as follows:
Turn off the gas and disconnect the power ahead of the unit.
Remove the entire gas unit from the combustion chamber (see fig. 14 - 15).
Remove the pilot burner (fig. 16).
Remove the main burners from the manifold.
Change the main and pilot nozzles.
Reassemble carefully.
Perform the main nozzle gas pressure setting, as described above, and the pilot flame adjustment
utilizing the gas valve (fig. 11a - 11b).
Check that it all works properly and there is no gas leakage.
SIT 820 NOVA VALVE
(for mod. 51 - 68)
Pilot Burner
Ignition Main Burner
Ignition
Turning Off
Key
1On-off knob
2Gas pressure adjustment screw
3Inlet gas pressure point
4Outlet gas pressure point
5Pilot adjustment screw
6Protective plug

Pegasus F2 N T
15
fig. 11b
Decrease
Increase
Detail of
pressure
regulator
To measure the burner gas pressure, use the pressure point on the gas manifold pipe of the
burner assembly (see part 15 fig. 19).
HONEYWELL V4400C VALVE
(for mod. 85 - 102)
Key
1Ignition button
2Gas pressure adjustment screw
3Inlet gas pressure point
4Pilot adjustment screw
5Off button
6Protective plug
Fig. 11b

Pegasus F2 N T
16
3.2 System start-up
System start-up must be carried out by Qualified Personnel.
The following operations and checks are to be made at first ignition, and after all maintenance opera-
tions that involved disconnecting from the systems or an intervention on safety devices or parts of the
boiler.
Before lighting the boiler:
•Open any on-off valves between the boiler and the system.
•Check the airtightness of the gas system, proceeding with caution and using a soap and water
solution to detect any leaks in connections.
•Fill the water system and make sure that all air contained in the boiler and the system has been vented by
opening the air vent valve on the boiler and any vent valves on the system.
•Make sure there are no water leaks in the system or boiler.
•Make sure the electrical system is properly connected.
•Make sure that the unit is connected to a good earthing system.
•Make sure that the pressure and gas flow values are those required for heating.
•Make sure there are no flammable liquids or materials in the immediate vicinity of the boiler.
Lighting the boiler
•Open the gas valve ahead of the boiler.
•Vent the air from the pipe ahead of the gas valve.
•Follow the user operating sequence described in paragraph 1.3.
The boiler switch 4 of fig. 19 has 3 positions, “0-1-TEST”; the first two have the on-off function,
the third (unstable) must only be used for service and maintenance purposes.
In case of an electrical power failure while the boiler is working, the burners will go out and re-
ignite automatically when power is restored.
Checks during operation
•Check the airtightness of the fuel circuit and water systems.
•Check the efficiency of the flue and fume ducts while the boiler is working.
•Check that the water is circulating properly between the boiler and the systems.
•Check the proper ignition of the boiler by performing various tests, turning it on and off with
the room thermostat or boiler thermostat.
•Make sure that the fuel consumption indicated on the meter corresponds to that given in the
technical data table in chap. 4.
Turning off
To turn the unit off temporarily or for an extended period, refer to the user instructions given
in paragraph 1.3.

Pegasus F2 N T
17
To avoid damage caused by freezing during long shutdowns in winter, it is advisable to drain all
water from the boiler and the system; or add a suitable antifreeze to the heating system.
3.3 Maintenance
The following operations must only be carried out by Qualified Personnel.
Seasonal inspection of the boiler and flue
It is advisable to carry out the following checks at least once a year:
•The control and safety devices (gas valve, thermostats, etc.) must function correctly.
•The fume ducts must be free of obstructions and leaks.
•The gas and water systems must be airtight.
•The burner and boiler shell must be clean. Follow the instructions in the next paragraph.
•The thermocouple must be free of scale and properly positioned (see fig. 16).
•The water pressure in the cold water system must be about 1 bar; otherwise, bring it to that value.
•The expansion tank, if present, must be filled.
•The gas flow and pressure must correspond to that given in the respective tables (par. 4.3).
•The circulating pumps must not be blocked.
Safety devices
The Pegasus F2 N T boiler is equipped with devices that guarantee safety in the event of
operation anomalies.
Temperature limiter (safety thermostat) with automatic reset
This device prevents the water temperature in the system from exceeding boiling point. The maximum
intervention temperature is 110°C.
Automatic reset of the temperature limiter can only occur with cooling of the boiler (the temperature
must drop by at least 10°C) and identification and consequent elimination of the problem that
caused the shutdown.
Fume sensor (fume thermostat) safety device with manual reset
The boiler is equipped with a device to control the evacuation of fumes (fume sensor - pos. 7 of fig.
19). If there are any anomalies in the fume evacuation system with consequent return of burnt gas
in the environment, the unit shuts down. The hood is equipped with a temperature sensor bulb for
measuring and controlling the fume temperature.
Any leak of burnt gases into the environment causes an increase in the temperature detected by the
bulb, which causes the boiler to turn off within 2 minutes shutting off the gas to the burner. If the fume
sensor intervenes, unscrew the protection cover (7 of fig. 19) located on the control panel and manually
reset the device. The boiler will resume operation.
If the sensor has to be replaced due to breakdown, only use original accessories and ensure that the
electrical connections and positioning of the bulb have been correctly carried out.
The fume sensor must not be cut-out for any reason!

Pegasus F2 N T
18
Combustion analysis
A point for sampling fumes has been included inside the boiler in the upper part of the anti-backflow
device (see fig. 13).
To take the sample:
1) Remove the top panel of the boiler (see Fig. 6 - 7).
2) Remove the insulation on the anti-backflow device
3) Open the fume sampling point;
4) Insert the probe;
5) Adjust the boiler temperature to the maximum.
6) Wait 10-15 minutes for the boiler to stabilize*
7)Take the measurement.
*Analyses made with
an unstabilized boiler
can cause measurement
errors.
Fume sampling point
Fig. 13
Opening the front panel
To open the front panel, see the sequence in fig. 12.
1
2
Fig. 12
Before carrying out any operation inside the boiler,
disconnect the electrical power supply and close
the gas cock upstream.

Pegasus F2 N T
19
Disassembly and cleaning the burner unit
to remove the burner unit:
•Disconnect the electrical power supply and turn off the gas ahead of the boiler.
•Extract the safety thermostat bulb (part 8 fig. 19) from its housing sheath.
•Disconnect the power cable from the gas valve.
•Disconnect the piezoelectric igniter cable.
•Unscrew the nut fixing the gas feed pipe ahead of the gas valve (fig. 14). On model 102,
unscrew the 2 nuts.
•Unscrew the two nuts attaching the combustion chamber door to the cast iron elements of
the boiler (fig. 15).
•Remove the burner assembly and combustion chamber door.
At this point, check and clean the burners. Only use a non-metallic brush or compressed air to clean
the burners and thermocouple; never use chemical products.
On completion, fit it all back together in reverse order.
fig. 14
fig. 15

Pegasus F2 N T
20
Key
1 Combustion chamber door
2Inspection door
3Pilot burner
4Ignition electrode
5Thermocouple
6Pilot nozzle
7Gas supply pipe
Fig. 16
Pilot light unit
5
33- 4 mm
4
7
Cleaning the boiler and flue
To properly clean the boiler (fig. 17):
•Turn off the gas ahead of the unit and disconnect the electrical
power supply.
•Take the front panel off the boiler (see Fig. 12).
•Lift the boiler cover by pressing upwards (see also Fig. 6-7).
•Remove the insulation covering the anti-backflow device.
•Remove the fume chamber closing plate and the associated insu-
lation.
•Remove the burner unit (see preceding paragraph).
•Usingthebrushprovided,cleanthefumeevacuationducts between
the cast iron elements of the boiler shell, lastly removing the dirt
with a vacuum cleaner.
•Carefully reassemble all the previously disassembled parts and
check the airtightness of the gas circuit and the combustion
ducts.
•During cleaning operations take care not to damage the fume
thermostat bulb mounted on the back of the fume chamber.
Fig. 17
Key
1Screws securing the boiler cover
2Boiler cover
3Fume chamber closing plate
4Fume chamber insulation
5Brush
6Combustion analysis plug
5
3
2
6
1
4