Ferroli PEGASUS D Ki 100 User manual

3540L870
cod. 3540L870 — 03/2009 (Rev. 00)
PEGASUS D Ki 100
INSTRUCTIONS FOR USE, INSTALLATION AND MAINTENANCE
NÁVOD K OBSLUZE, INSTALACI A ÚDRŽBĚ
VEJLEDNING I BRUG, INSTALLATION OG VEDLIGEHOLDELSE
HASZNÁLATI, BESZERELÉSI ÉS KARBANTARTÁSI UTASÍTÁS
INSTRUKCJA OBSłUGI, INSTALACJI I KONSERWACJI
РУКОВОДСТВО ПО ЭКСПЛУАТАЦИИ, МОНТАЖУ ИТЕХОБСЛУЖИВАНИЮ

PEGASUS D Ki 100
2EN
B
Declaration of conformity
Manufacturer: FERROLI S.p.A.
Address: Via Ritonda 78/a 37047 San Bonifacio VR Italy
declares that this unit complies with the following EU directives:
• Gas Appliance Directive 90/396
• Efficiency Directive 92/42
• Low Voltage Directive 73/23 (amended by 93/68)
• Electromagnetic Compatibility Directive 89/336 (amended by 93/68)
President and Legal Representative
Cav. del Lavoro
Dante Ferroli
BThis 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.
AThis symbols calls attention to a note or important notice.
cod. 3540L870 - 03/2009 (Rev. 00)
• Carefully read the warnings in this instruction book-
let since they provide important information on safe
installation, use and maintenance.
• This instruction booklet is an integral part of the
product and must be carefully kept by the user for fu-
ture 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 qualified personnel, according to cur-
rent regulations and the manufacturer's instructions.
• Incorrect installation or poor maintenance can cause
damage or physical injury. The manufacturer de-
clines any responsibility for damage caused by er-
rors in installation and use or by failure to follow the
manufacturer's instructions.
• Before carrying out any cleaning or maintenance op-
eration, disconnect the unit from the electrical power
supply using the switch and/or the special cut-off de-
vices.
• 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 qualified
personnel. Any repair/replacement of products must
only be carried out by qualified professional person-
nel using exclusively genuine parts. Failure to com-
ply with the above could affect the safety of the unit.
• Periodical maintenance carried out by qualified per-
sonnel 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 im-
proper 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.
• The images shown in this manual are a simplified
representation of the product. In this representation
there may be slight, unimportant differences with the
supplied product.

PEGASUS D Ki 100
3
3540L870 cod. 3540L870 - 03/2009 (Rev. 00)
1 Operating instructions ............................................................................................................ 4
1.1 Introduction.............................................................................................................................................4
1.2 Control panel ..........................................................................................................................................4
1.3 Turning on and off ..................................................................................................................................5
1.4 Adjustments............................................................................................................................................7
2 Installation .............................................................................................................................. 11
2.1 General Instructions .............................................................................................................................11
2.2 Place of installation ..............................................................................................................................11
2.3 Plumbing connections ..........................................................................................................................11
2.4 Gas connection ....................................................................................................................................12
2.5 Electrical connections...........................................................................................................................12
2.6 Connection to the flue ..........................................................................................................................13
3 Service and maintenance...................................................................................................... 14
3.1 Adjustments..........................................................................................................................................14
3.2 Start-up.................................................................................................................................................16
3.3 Maintenance.........................................................................................................................................17
3.4 Troubleshooting....................................................................................................................................21
4 Technical data and characteristics ...................................................................................... 23
4.1 Dimensions, connections and main components .................................................................................23
4.2 Pressure losses....................................................................................................................................24
4.3 Technical data table .............................................................................................................................25
4.4 Wiring diagram .....................................................................................................................................26

PEGASUS D Ki 100
4EN
cod. 3540L870 - 03/2009 (Rev. 00)
1. Operating instructions
1.1 Introduction
Dear Customer,
Thank you for choosing PEGASUS D Ki 100, a floor-standing boiler FERROLI featuring advanced design, cutting-edge
technology, high reliability and quality construction. Please read this manual carefully and keep it for future reference.
PEGASUS D Ki 100 is a high-efficiency heat generator for heating and domestic hot water production running on nat-
ural or liquefied gas and regulated by an advanced electronic control system.
PEGASUS D Ki 100 it is equipped with a rapid hot water storage tank in AISI316L stainless steel, and protected against
corrosion by a magnesium anode.
The boiler shell consists of cast-iron elements whose particular shape guarantees high exchange efficiency in all oper-
ating conditions and an open-flue burner equipped with electronic ignition and ionisation flame control.
1.2 Control panel
fig. 1 - Control panel
Key
1 = DHW temperature setting decrease button
2 = DHW temperature setting increase button
3 = Heating system temperature setting decrease
button
4 = Heating system temperature setting increase
button
5 = Display
6 = Summer / Winter mode selection button
7 = Economy / Comfort mode selection button
8 = Reset button
9 = Unit On / Off button
10 = "Sliding Temperature" menu button
11 = Set DHW temperature reached
12 = DHW symbol
13 = DHW operation
14 = DHW outlet temperature / setting
15 = Eco (Economy) or Comfort mode
16 = External sensor temperature (with optional ex-
ternal probe)
17 = Appears on connecting the external Probe or the
Remote Timer Control (optionals)
18 = Room temperature (with optional Remote Timer
Control)
19 = Burner On
20 = Antifreeze operation
21 = Heating system pressure
22 = Fault
23 = Heating delivery temperature / setting
24 = Heating symbol
25 = Heating operation
26 = Set heating delivery temperature reached
27 = Summer mode
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5791021
8643
12 1411
13
15 16
17182021222325
2426
27
19

PEGASUS D Ki 100
5EN cod. 3540L870 - 03/2009 (Rev. 00)
Indication during operation
Heating
A heating demand (generated by the Room Thermostat or Remote Timer Control) is indicated by flashing of the hot air
above the radiator (details 24 and 25 - fig. 1).
The heating graduation marks (detail 26 - fig. 1) light up as the heating sensor temperature reaches the set value.
fig. 2
DHW (Comfort)
A DHW demand (generated by drawing domestic hot water) is indicated by flashing of the hot water under the tap (de-
tails 12 and 13 - fig. 1). Make sure the Comfort function (detail 15 - fig. 1) is activated
The DHW graduation marks (detail 11 - fig. 1) light up as the DHW sensor temperature reaches the set value.
fig. 3
Exclude hot water tank (economy)
Hot water tank temperature maintaining/heating can be excluded by the user. If excluded, domestic hot water will not
be delivered.
When hot water tank heating is activated (default setting), the COMFORT symbol (detail 15 - fig. 1) is activated on the
display, and when off, the ECO symbol (detail 15 - fig. 1) is activated on the display
The hot water tank can be deactivated by the user (ECO mode) by pressing the button (detail 7 - fig. 1). To ac-
tivate COMFORT mode, press the button (detail 7 - fig. 1) again.
1.3 Turning on and off
Boiler not electrically powered
fig. 4 - Boiler not electrically powered
BThe antifreeze system does not work when the power and/or gas to the unit are turned off. To avoid damage
caused by freezing during long idle periods in winter, it is advisable to drain all water from the boiler, DHW
circuit and system; or drain just the DHW circuit and add a suitable antifreeze to the heating system, complying
with that prescribed in sec. 2.3.
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PEGASUS D Ki 100
6EN
cod. 3540L870 - 03/2009 (Rev. 00)
Boiler lighting
• Open the fuel on-off valves.
• Switch on the power to the unit.
fig. 5 - Boiler lighting
• For the next 120 seconds the display will show FH which identifies the heating system air venting cycle.
• During the first 5 seconds the display will also show the card software release.
• When the message FH disappears, the boiler is ready to operate automatically whenever domestic hot water is
drawn or in case of a room thermostat demand.
AIf, after correctly carrying out the lighting procedure, the burners do not light and fault A01 appears on the dis-
play, wait about 15 seconds then press the RESET button. The flame controller thus reset will repeat the light-
ing cycle. If the burners do not light after a number of attempts, consult the faults section.
AIn case of a power failure while the boiler is working, the burners will go out and relight automatically when the
power is restored.
Turning the boiler off
Press the button (detail 9 - fig. 1) for 1 second.
fig. 6 - Turning the boiler off
When the boiler is turned off, the electronic board is still powered.
Domestic hot water and heating operation are disabled. The antifreeze system remains activated.
To relight the boiler, press the button (detail 9 fig. 1) again for 1 second.
fig. 7
The boiler will be immediately ready to operate whenever domestic hot water is drawn or in case of a room thermostat
demand.
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PEGASUS D Ki 100
7EN cod. 3540L870 - 03/2009 (Rev. 00)
Shutting down the boiler for prolonged periods
To turn off the boiler:
• Press the ON/OFF button (9 - fig. 1).
• Close the gas cock ahead of the boiler.
• Disconnect the power supply to the unit.
BTo avoid damage caused by freezing during long idle periods in winter, it is advisable to drain all water from
the boiler and system; or add a suitable antifreeze to the heating system.
1.4 Adjustments
Summer/Winter changeover
Press the button (detail 6 - fig. 1) for 1 second.
fig. 8
The display activates the Summer symbol (detail 27 - fig. 1): the boiler will only deliver domestic hot water. The anti-
freeze system remains activated.
To deactivate Summer mode, press the button (detail 6 - fig. 1) again for 1 second.
Heating temperature setting
Operate the heating buttons (details 3 and 4 - fig. 1) to adjust the temperature from a min. of 30°C to a max.
of 90°C; it is advisable not to operate the boiler below 45°C.
fig. 9
Hot water temperature adjustment
Operate the DHW buttons (details 1 and 2 - fig. 1) to adjust the temperature from a min. of 10°C to a max.
of 65°C.
fig. 10
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PEGASUS D Ki 100
8EN
cod. 3540L870 - 03/2009 (Rev. 00)
Room temperature adjustment (with optional room thermostat)
Using the room thermostat, set the temperature desired in the rooms. If the room thermostat is not installed the boiler
will keep the heating system at its setpoint temperature.
Room temperature adjustment (with optional remote timer control)
Using the remote timer control, set the temperature desired in the rooms. The boiler unit will set the system water ac-
cording to the required room temperature. For information on the remote timer control, please refer to its user's manual.
Sliding Temperature
When the optional external probe is installed the control panel display (detail 5 - fig. 1) shows the actual outside tem-
perature read by the probe. The boiler control system operates with "Sliding Temperature”. In this mode, the tempera-
ture of the heating system is controlled according to the outside weather conditions, to ensure high comfort and energy
saving throughout the year. In particular, as the outside temperature increases the system delivery temperature de-
creases according to a specific "compensation curve”.
With Sliding Temperature adjustment, the temperature set with the heating buttons (details 3 and 4 - fig. 1)
becomes the maximum system delivery temperature. It is advisable to set the maximum value to allow system adjust-
ment throughout its useful operating range.
The boiler must be adjusted at the time of installation by qualified personnel. Adjustments can in any case be made by
the user to improve comfort.
Compensation curve and curve offset
Press the button (detail 10 - fig. 1) once to display the compensation curve (fig. 11), which can be modified with the
DHW buttons (details 1 and 2 - fig. 1).
Adjust the required curve from 1 to 10 according to the characteristic (fig. 13).
By setting the curve to 0, sliding temperature adjustment is disabled.
fig. 11 - Compensation curve
Press the heating buttons (details 3 and 4 - fig. 1) to access parallel curve offset (fig. 14), modifiable with the
DHW buttons (details 1 and 2 - fig. 1).
fig. 12 - Parallel curve offset
Press the button (detail 10 - fig. 1) again to exit parallel curve adjustment mode.

PEGASUS D Ki 100
9EN cod. 3540L870 - 03/2009 (Rev. 00)
If the room temperature is lower than the required value, it is advisable to set a higher order curve and vice versa. Pro-
ceed by increasing or decreasing in steps of one and check the result in the room.
fig. 13 - Compensation curves
fig. 14 - Example of parallel compensation curve shift
Adjustments from Remote Timer Control
AIf the Remote Timer Control (optional) is connected to the boiler, the above adjustments are managed accord-
ing to that given in table 1. Also, the control panel display (detail 5 - fig. 1) shows the actual room temperature
read by the Remote Timer Control.
Table. 1
Heating temperature adjustment Adjustment can be made from the Remote Timer Control menu and the boiler
control panel.
Domestic hot water temperature adjustment Adjustment can be made from the Remote Timer Control menu and the boiler
control panel.
Summer/Winter switchover Summer mode has priority over a possible Remote Timer Control heating
demand.
Eco/Comfort selection
On disabling DHW from the Remote Timer Control menu, the boiler selects
the Economy mode. In this condition, the button 7 - fig. 1 on the boiler panel
is disabled.
On enabling DHW from the Remote Timer Control menu, the boiler selects
the Comfort mode. In this condition it is possible select one of the two modes
with the button 7 - fig. 1 on the boiler panel.
Sliding Temperature Both the Remote Timer Control and the boiler card manage Sliding Tempera-
ture adjustment: of the two, the boiler card Sliding Temperature has priority.
20
30
40
50
60
70
80
90
85
20 10 0 -10 -20
1
2
3
4
5
68910 7
20
30
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50
60
70
80
90
85
20 10 0 -10 -20
1
2
3
4
5
6
8910 7
20 10 0 -10 -20
20
30
40
50
60
70
80
90
85
1
2
3
4
568910 7
OFFSET = 20 OFFSET = 40

PEGASUS D Ki 100
10 EN
cod. 3540L870 - 03/2009 (Rev. 00)
Water system pressure adjustment
The filling pressure with system cold, read on the boiler water gauge, must be approx. 1.0 bar. If the system pressure
falls to values below minimum, the boiler card will activate fault F37 (fig. 15).
fig. 15 - Low system pressure fault
Operate the filling cock (detail 1 - fig. 16) and bring the system pressure to a value above 1.0 bar.
fig. 16 - Filling cock
AOnce the system pressure is restored, the boiler will activate the 120-second air venting cycle indicated on the
display by FH.
At the end of the operation always close the filling cock (detail 1 - fig. 16)
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1

PEGASUS D Ki 100
11EN cod. 3540L870 - 03/2009 (Rev. 00)
2. Installation
2.1 General Instructions
BOILER INSTALLATION MUST ONLY BE PERFORMED BY QUALIFIED PERSONNEL, IN ACCORDANCE WITH
ALL THE INSTRUCTIONS GIVEN IN THIS TECHNICAL MANUAL, THE PROVISIONS OF CURRENT LAW, THE PRE-
SCRIPTIONS OF NATIONAL AND LOCAL STANDARDS AND THE RULES OF PROPER WORKMANSHIP.
2.2 Place of installation
The boiler unit must be installed in a specific room with ventilation openings to the outside as prescribed by current reg-
ulations. If there are several burners or suction units that can work together in the same room, the ventilation openings
must be sized for simultaneous operation of all the units. The place of installation must be free of flammable materials
or objects, corrosive gases, powders or volatile substances that, conveyed by the burner fan, can obstruct the internal
lines of the burner or the combustion head. The room must be dry and not exposed to rain, snow or frost.
AIf the unit is enclosed in a cabinet or mounted alongside, a space must be provided for removing the casing
and for normal maintenance operations.
2.3 Plumbing connections
The heating capacity of the unit must be previously established by calculating the building's heat requirement according
to current regulations. The system must be provided with all the components for correct and regular operation. It is ad-
visable to install on-off valves between the boiler and heating system allowing the boiler to be isolated from the system
if necessary.
BThe safety valve outlet must be connected to a funnel or collection pipe to prevent water spurting onto the floor
in case of overpressure in the heating circuit. Otherwise, if the discharge valve cuts in and floods the room,
the boiler manufacturer cannot be held liable.
Do not use the water system pipes to earth electrical appliances.
Before installation, carefully wash all the pipes of the system to remove any residuals or impurities that could affect prop-
er operation of the unit.
Carry out the relevant connections according to the diagram in cap. 4.1 "Dimensions, connections and main compo-
nents" and the symbols given on the unit.
Water system characteristics
In the presence of water harder than 25° Fr (1°F = 10ppm CaCO3), use suitably treated water in order to avoid possible
scaling in the boiler. Treatment must not reduce the hardness to values below 15°F (Decree 236/88 for uses of water
intended for human consumption). Treatment of the water used is indispensable in case of very large systems or with
frequent introduction of replenishing water in the system.
BIf water softeners are installed at the boiler cold water inlet, make sure not to reduce the water hardness too
much, as this could cause early deterioration of the magnesium anode in the hot water tank.
Antifreeze system, antifreeze fluids, additives and inhibitors
The boiler is equipped with an antifreeze system that turns on the boiler in heating mode when the system delivery water
temperature falls under 6°C. The device will not come on if the electricity and/or gas supply to the unit are cut off. If it
becomes necessary, it is permissible to use antifreeze fluid, additives and inhibitors only if the manufacturer of these
fluids or additives guarantees they are suitable for this use and cause no damage to the heat exchanger or other com-
ponents and/or materials of the boiler unit and system. It is prohibited to use generic antifreeze fluid, additives or inhib-
itors that are not expressly suited for use in heating systems and compatible with the materials of the boiler unit and
system.

PEGASUS D Ki 100
12 EN
cod. 3540L870 - 03/2009 (Rev. 00)
2.4 Gas connection
BBefore making the connection, make sure the unit is arranged for operation with the type of fuel available and
carefully clean all the system gas pipes to remove any residuals or impurities that could affect proper operation
of the boiler.
The gas must be connected to the respective union (see fig. 25) in conformity with current regulations, with a rigid metal
pipe or with a continuous surface flexible s/steel tube, installing a gas cock between the system and boiler. Make sure
all the gas connections are tight.
The capacity of the gas meter must be sufficient for the simultaneous use of all the appliances connected to it. The di-
ameter 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 pressure losses, in conformity with the current regulations.
BDo not use the gas pipes to earth electrical appliances.
2.5 Electrical connections
Connection to the electrical grid
BThe unit's electrical safety is only guaranteed when correctly connected to an efficient earthing system exe-
cuted 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.
The boiler is prewired and provided with a Y-cable and plug 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. During installation or when changing the power cable, the earth wire must be left 2 cm longer than the others.
BThe user must never change the unit's power cable. If the cable gets damaged, switch off the unit and have it
changed solely by professionally qualified personnel. If changing the electric power cable, use solely “HAR
H05 VV-F” 3x0.75 mm2 cable with a maximum outside diameter of 8 mm.
Room thermostat (optional)
BIMPORTANT: THE ROOM THERMOSTAT MUST HAVE VOLTAGE-FREE CONTACTS. CONNECTING 230
V TO THE ROOM THERMOSTAT TERMINALS WILL PERMANENTLY DAMAGE THE ELECTRONIC
BOARD.
When connecting time controls or a timer, do not take the power supply for these devices from their breaking
contacts Their power supply must be by means of direct connection from the mains or with batteries, depend-
ing on the kind of device.
Accessing the electrical terminal block
Undo the two screws “A” located on the top part of the control panel and remove the cover.
fig. 17 - Accessing the terminal board
A

PEGASUS D Ki 100
13EN cod. 3540L870 - 03/2009 (Rev. 00)
2.6 Connection to the flue
The flue connection pipe diameter 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. Comply with the current standards
regarding installation and sizes of the flues and connection pipe.
The diameter of the anti-backflow device collar is given in fig. 25.

PEGASUS D Ki 100
14 EN
cod. 3540L870 - 03/2009 (Rev. 00)
3. Service and maintenance
3.1 Adjustments
All adjustment, conversion, start-up and maintenance operations described below must only be carried out by Qualified
Personnel (meeting the professional technical requirements prescribed by current regulations) such as those of the Lo-
cal After-Sales Technical Service.
TEST mode activation
Press the heating buttons (part. 3 and 4 - fig. 1) at the same time for 5 seconds to activate TEST mode. The
boiler lights at maximum power.
The heating symbol (detail 24 - fig. 1) and DHW symbol (detail 12 - fig. 1) flash on the display.
fig. 18 - Operation in TEST mode
To deactivate TEST mode, repeat the activation sequence.
In any case, TEST mode is automatically deactivated after 15 minutes.
Heating system output adjustment
On PEGASUS D Ki 100 boilers, the firebox heating power and therefore the heat output delivered to the heating water
can only be adjusted by means of the main burner through the gas valve, (see fig. 19). The diagrams given in the section
cap. 4.2 "Pressure losses" indicate the variation in heat output delivered to the water according to the change in burner
operating pressure. Being able to adjust boiler output to the actual heating requirements means above all reducing heat
losses, and therefore obtaining fuel saving. Also, with the variation in output, also regulated by the provisions, the boilers
keep their efficiency levels and combustion characteristics practically unchanged
This operation is carried out with the boiler working and the water storage tank heated.
1. Using a small screwdriver, remove the secondary operator protection cap 5 of the gas valve of fig. 19.
2. Connect a manometer to the pressure point 2 (fig. 19) located below the gas valve, and turn the boiler thermostat
knob to the maximum value.
3. Adjust the pressure to the required value by means of the screw 6 (fig. 19), referring to the diagrams given in section
cap. 4.2 "Pressure losses".
4. Then turn the burner on and off 2 or 3 times by means of the control thermostat and check that the pressure value
is that just set; otherwise, another adjustment must be made to bring the pressure to the correct value.
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PEGASUS D Ki 100
15EN cod. 3540L870 - 03/2009 (Rev. 00)
Gas conversion
The unit can operate on natural gas (G20) or liquefied gas (G31) and is factory-set for use with one of these two gases,
as clearly shown on the packing and on the dataplate. Whenever a different gas to that for which the unit is preset has
to be used, a conversion kit will be required, proceeding as follows:
1. Replace the nozzles at the main burner and pilot burner, fitting the nozzles specified in the technical data table in
cap. 4.3 "Technical data table", according to the type of gas used
2. Remove the small protection cap 3 (fig. 19) from the gas valve. Using a small screwdriver, adjust the ignition “STEP”
for the required gas (G20 or G31); then refit the cap.
3. Adjust the gas pressure at the burner, setting the values given in the technical data table for the type of gas used.
4. Apply the sticker contained in the conversion kit, near the dataplate as proof of the conversion.
fig. 19 - Gas conversion
Key
1Pressure point upstream
2Pressure point downstream
3Protective cap
4Ignition “STEP” regulator
5Protective cap
6Gas pressure adjustment screw
AHoneywell VK 4100 C 1075 gas valve
BDecrease pressure
CIncrease pressure
DIgnition “STEP” adjustment for G20-G25
NATURAL gas
EIgnition step adjustment for G30-G31 LIQ-
UEFIED gas

PEGASUS D Ki 100
16 EN
cod. 3540L870 - 03/2009 (Rev. 00)
3.2 Start-up
BSystem start-up must be carried out by Qualified Personnel. Checks to be made at first lighting, and after all
maintenance operations that involved disconnecting from the systems or work on safety devices or parts of
the boiler:
Before lighting the boiler
• Open any on-off valves between the boiler and the systems.
• Check the tightness 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 all air contained in the boiler and 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, domestic hot water circuits, connections or boiler.
• Check the correct connection of the electrical system.
• Make sure the unit is connected to an efficient earthing system.
• Make sure there are no flammable liquids or materials in the immediate vicinity of the boiler.
• Vent the air from the gas pipes by means of the gas valve pressure point 1 (fig. 19).
Lighting
Open the fuel on-off valves.
Connect the power to the unit.
For the next 120 seconds the display will show FH which identifies the heating system air venting cycle.
During the first 5 seconds the display will also show the card software release.
When the message FH disappears, the boiler is ready to operate automatically whenever domestic hot water is drawn
or in case of a room thermostat demand.
AIf, after correctly carrying out the lighting procedures, the burners do not light and the message A01 appears
on the display, wait about 15 seconds and then press the RESET pushbutton. The reset controller will repeat
the lighting cycle. If the burners do not light after several of attempts, consult the "Troubleshooting" section.
AIn case of a power failure while the boiler is working, the burners will go out and relight automatically when the
power is restored.
Checks during operation
• Make sure the fuel circuit and water systems are tight.
• Check the efficiency of the flue and fume ducts during boiler operation.
• Make sure the water is circulating properly between the boiler and the systems.
• Check correct lighting of the boiler, by turning it on and off several times.
• Make sure the fuel consumption indicated on the meter matches that given in the technical data table on cap. 4.3
"Technical data table".
• Check the correct flow of domestic hot water with the Δt given in the technical data table: do not trust measurements
made with empirical systems. The measurement should be made with special instruments and as close as possible
to the boiler, also considering the heat lost from the pipes.
• During heating operation, make sure circulating pump stops when a hot water tap is opened, and that there is regular
production of domestic hot water.

PEGASUS D Ki 100
17EN cod. 3540L870 - 03/2009 (Rev. 00)
3.3 Maintenance
BThe following operations must only be carried out by Qualified Personnel.
Seasonal inspection of the boiler and flue
It is advisable to have the following checks carried out at least once a year:
• The control and safety devices (gas valve, thermostats, etc.) must function correctly.
• The fume ducts must be clean and free of obstructions.
• The gas and water systems must be tight.
• The burner and exchanger must be clean. Follow the instructions in the next section.
• The electrodes must be free of scale and properly positioned (see fig. 24).
• The water pressure in the system when cold must be approx. 1 bar; otherwise bring it to that value.
• The expansion tank must be filled.
• The gas flow and pressure must correspond to that given in the respective technical data tables.
• The circulating pumps must not be blocked.
Opening the front panel
To open the front panel, see the sequence in fig. 20.
BBefore carrying out any operation inside the boiler, disconnect the power supply and close the gas cock up-
stream.
fig. 20 - Opening the front panel

PEGASUS D Ki 100
18 EN
cod. 3540L870 - 03/2009 (Rev. 00)
Cleaning the boiler and flue
To clean the boiler properly (fig. 21):
• Close the gas cock ahead of the unit and disconnect the power supply.
• Remove the front panel of the boiler.
• Lift the casing cover by pressing upwards.
• Remove the insulation placed over the anti-backflow device.
• Remove the fume chamber closing plate.
• Remove the burner assembly (see next section).
• Clean from the top downwards, using a flue brush.
• Clean the fume exhaust ducts between the cast iron elements of the boiler shell with a vacuum cleaner.
• Carefully refit all the previously removed parts and check the tightness of the gas circuit and combustion ducts.
• During cleaning operations take care not to damage the fume thermostat bulb at the back of the fume chamber.
fig. 21 - Boiler cleaning
1Casing cover
2Fume chamber closing plate
3Flue brush
4Magnesium anode
5Flange
6Hot water tank front panel
7Combustion analysis plug
4
3
2
1
5
7
6

PEGASUS D Ki 100
19EN cod. 3540L870 - 03/2009 (Rev. 00)
Hot water tank cleaning (to be carried out every 2-3 years, depending on water aggressiveness)
• Remove the front panel of the hot water tank (6 - fig. 21).
• Close the hot water tank on-off valves and open the drain cock.
• After draining, remove the inspection flange and carry out cleaning. Use specific products available on the market.
Do not use metal tools to remove the scale.
• After cleaning, refit the inspection flange and hot water tank front panel and open the on-off valves.
Magnesium anode
The degree of deterioration of the magnesium anode (4 - fig. 21) can be checked directly from the outside by unscrewing
it from the hot water tank flange (after turning off the domestic hot water supply and draining the hot water tank).
This check is advisable at least once a year.
If the water is very hard, above 20 degrees French, install a water softener in the system.
Draining the hot water tank and heating system
• To drain the hot water tank, use the drain cock 233 of fig. 25 after closing the valves for filling from the water system;
use a hot water drawing point (washbasin, shower, etc.) as a vent.
• To drain the heating system completely, use the cock 275 of fig. 25 after releasing the shutters of the two non-return
valves detail 179 of fig. 25 (also see fig. 22). Use the radiator valves as vents.
If the boiler is connected to the system by service gate valves, check their complete opening. If the boiler is posi-
tioned higher than the radiators, the part of the system including the radiators must be drained separately.
• To drain just the water contained in the boiler, close the on-off valves and fully open the cock (255 - fig. 25). Then
release the shutters of the non-return valves (179 - fig. 25). Lastly, open the cock 197 of fig. 25).
ABefore filling the system again, remember to close the drain cock and radiator vent valves and lock the shutters
of the non-return valves 179 of fig. 25.
fig. 22
A - Shutter locked
B - Shutter released
Combustion analysis
A point for sampling fumes has been included inside the boiler, in the upper part of the anti-backflow device (detail 7 -
fig. 21).
To take the sample:
1. Remove the upper panel of the boiler
2. Remove the insulation placed over the anti-backflow device;
3. Open the fume sampling point;
4. Insert the probe;
5. Activate the TEST mode
6. Wait 10-15 minutes for the boiler to stabilise*
7. Take the measurement.
AAnalyses made with an unstabilised boiler can cause measurement errors.
A B

PEGASUS D Ki 100
20 EN
cod. 3540L870 - 03/2009 (Rev. 00)
Removing and cleaning the burner assembly
To remove the burner assembly:
• Disconnect the electrical power supply and turn off the gas ahead of the boiler;
• Undo the nut fixing the gas supply pipe ahead of the gas valve;
• Undo the two nuts fixing the combustion chamber door to the cast iron elements of the boiler (fig. 23)
• Remove the burner assembly and combustion chamber door.
Then check and clean the main burners and pilot burner. Use a non-metal brush or compressed air to clean the burners;
never use chemical products.
fig. 23 - Removing the burners
Pilot burner assembly
fig. 24 - Pilot burner
1. Combustion chamber door
2. Inspection door
3. Pilot burner
4. Ignition electrode
5. Detection electrode
6. Pilot nozzle
7. Gas supply pipe