Ferroli OPTIMAX 25 OV Troubleshooting guide

OPTIMAX 25 OV
wall-mounting,
pre-mixed
condensing gas boiler
INSTRUCTIONS FOR USE INSTALLATION AND MAINTENANCE
cod. 3544708/3 - 08/2004

Optimax 25 OV
2
IMPORTANT
Your “benchmark” Installation, Commissioning and Service Record Log Book will be enclosed in
your customer information pack.
“This record must be completed and left with the end user”.
Ferroli is a member of the Benchmark initiative and fully supports the aims of the programme.
Benchmark has been introduced to improve the standards of installation and commissioning of central
heating systems in the UK and to encourage the regular servicing of all central heating systems to
ensure safety and efficiency.
Please see installation and servicing guidelines.
• Read the warnings given in this manual thoroughly.
They provide important information for safe instal-
lation, use and maintenance
• Keep the manual carefully for future consultation.
• The instruction manual is an integral and essential
part of the product and must be kept safely by the
user.
• If the appliance is sold or transferred to another
owner or if the owner moves, leaving the appliance
behind, always ensure that the manual is kept with
the appliance for consultation by the new owner
and /or installer.
• Incorrect installation or poor maintenance absolves
the manufacturer from all liability for damage to
people or property.
• Installation and maintenance must be carried out
in conformity with current legislation, according
to the manufacturer’s instructions and by qualified
personnel.
• Before cleaning or maintenance, disconnect the
appliance from the mains via the switch on the
appliance or a suitable isolating device.
• In the event of malfunction or faulty operation, switch
off the appliance. Do not attempt to repair or carry
out any other operation on the appliance directly.
Contact qualified personnel only.
• Repairs or the replacement of components must be
carried out exclusively by qualified personnel using
original spare parts only. Failure to respect the above
my compromise the safety of the appliance.
• To guarantee efficient operation, the appliance must
be serviced once a year by an authorised service
centre.
• The appliance may not be used for purposes other
than those for which it was explicitly designed. Any
other use is considered improper and therefore dan-
gerous.
• Incorrect installation and use or failure to follow the
instructions provided by the manufacturer absolve
the manufacturer from all liability for damage.
• After unpacking, check that thecontents arecomplete
and undamaged.
• Keep packing out of reach of children as it is poten-
tially hazardous.
• To clean external parts, use a damp cloth moistened
with soapy water if necessary. Avoid using abrasive
cleaning products and solvents.
This symbol indicates “Caution” and is placed next to all safety warnings. Carefully
follow these instructions in order to avoid danger and damage to persons, and or
property.
This symbols calls attention to a note or an important notice for the installer/service
engineer.
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

Optimax 25 OV
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1. OPERATING INSTRUCTIONS..................................................................4
1.1 Introduction.............................................................................................................4
1.2 Control panel ..........................................................................................................5
1.3 Turning ON and OFF ..............................................................................................6
1.4 Adjustments ............................................................................................................6
1.5 Maintenance............................................................................................................7
1.6 Faults.......................................................................................................................7
2. INSTALLATION .......................................................................................8
2.1 General Instructions................................................................................................8
2.2 Boiler location .........................................................................................................9
2.3 Water connections ................................................................................................10
2.4 Connection to the gas system..............................................................................13
2.5 Electrical Connections ..........................................................................................13
2.6 Flue system ...........................................................................................................16
2.7 Condensate outlet connection .............................................................................22
3. SERVICE AND MAINTENANCE............................................................24
3.1 Adjustments ..........................................................................................................24
3.2 System start-up.....................................................................................................25
3.3 Maintenance..........................................................................................................26
3.4 Troubleshooting ....................................................................................................28
4 TECHNICAL CHARACTERISTICS AND DATA.........................................30
4.1 Dimensions and connections ................................................................................30
4.2 General view and main components ....................................................................31
4.3 Hydraulic diagram.................................................................................................32
4.4 Technical data table ..............................................................................................33
4.5 Wiring diagram .....................................................................................................34

4
Optimax 25 OV
1. OPERATING INSTRUCTIONS
1.1 Introduction
Dear Customer,
Thank you for choosing Optimax 25 OV, a FERROLI wall-mounted boiler of the latest generation, fea-
turing advanced design and cutting-edge technology.
Optimax 25 OV is a high-efficiency condensing pre-mix appliance for heating with extremely low emis-
sions, running on natural gas or LPG.
The boiler consists of an aluminium laminar heat exchanger providing effective condensation of the
water vapour contained in the flue gases, permitting extremely high efficiency.
Above the heat exchanger, in the boiler, there is a ceramic surface pre-mix burner, equipped with
electronic ignition and ionization flame control, which achieves extremely low emissions while ensuring
high reliability and long life operation.
The boiler is totally room sealed from the installation room: the air needed for combustion is drawn from
outside. The boiler also includes a modulating speed fan, modulating gas valve, safety valve, temperature
sensors, a safety thermostat and a flue gas sensor.
Thanks to the twin microprocessor control and adjustment system with advanced self-diagnosis, unit
operation is for the most part automatic. The power for heating is automatically governed by the control
system.
The user only has to set the temperature desired inside the home (by means of a room thermostat and
or regulate the temperature of the system). The adjustment and control system will provide optimum
operation throughout the year.
The display continuously provides information on the unit’s operating status and it is easily possible
to obtain additional information on the sensor temperatures, set-points, etc. or configure them. Any
operating problems associated with the boiler or system is immediately signalled by the display and, if
possible, corrected automatically.

5
Optimax 25 OV
1.2 Control panel
23 41
fig. 1
1 - System temperature adjustment / Summer/Winter selection
This knob is used to adjust the system temperature and can switch over between summer / winter. To
increase the system temperature, turn the knob clockwise; anticlockwise to decrease it. To select the
summer mode, turn it anticlockwise to the minimum setting.
2 - ON-OFF / Reset / Test
Holding the key down for at least 5 seconds turns off the boiler. To turn it back on, press the key again
for 5 seconds.
Pressing the key resets boiler operation after a lock-out.
Pressing the key 3 times within 3 seconds automatically takes you to TEST operation.
3 - Multi-function
In combination with the reset key, this is used to access the Installer menu.
4 - Operating display
On stand-by and during boiler operation this indicates the boiler operating temperature, burner flame
established (point at bottom lights up) or should a fault occur the appropriate code will appear within
the display.

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Optimax 25 OV
1.4 Adjustments
Room temperature adjustment (Via room thermostat )
Using the room thermostat, set the temperature desired in the room. Controlled by the room thermo-
stat, the boiler lights and heats the system water to the set system delivery setpoint temperature. The
boiler turns off when the desired temperature in the rooms is reached, it will re-light when the room
temperature falls below the setpoint level, providing there is still a demand from the time clock.
Heating temperature setting
To set the system delivery temperature, turn the knob (ref. 1 - fig. 1). It can be varied from a minimum
of 30 °C to a maximum of 90 °C.
Turning the knob sets the required temperature (clockwise to increase, anticlockwise
to decrease) that is shown on the display. During the setting, the display quickly
flashes and once defined it stops flashing after 2 sec. and reverts back to showing
the actual operating temperature.
Summer/Winter selection
To select Summer/Winter, use knob 1 (fig. 1).
Turning it onto (Summer) turns off the heating function but the frost protection stays active.
Turning it onto (Winter) turns on heating, via the time clock and room thermostat.
If the boiler is also used for hot water production do not select the summer position as this will
disable both heating and hot water modes.
1.3 Turning ON and OFF
Ignition
• Open the gas isolation valve on the boiler.
• Purge the gas supply taking the necessary precautions.
• Turn on the electrical switch at the 3amp switched fused spur.
• The boiler is now ready to function automatically whenever the external controls are calling for
heat.
Turning off
Press the key for 5 seconds (see fig. 1).
When the boiler is turned off with this key, the printed circuit board is still powered, heating operation
is disabled and the display appears the frost protection will remain active.
Close the gas isolation valve under the boiler and disconnect electrical power.
To avoid damage caused by freezing during long shutdowns in winter, it is advisable to drain all
water from the system.

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Optimax 25 OV
1.5 Maintenance
It is strongly recommended that an annual maintenance of the boiler is carried out by a qualified gas
engineer. Please refer to the “maintenance” section in this manual.
The casing, the control panel and the aesthetic parts of the boiler can be cleaned using a soft and damp
cloth.
Do not use abrasives or solvents.
1.6 Faults
In the event of operational faults, the display blinks and a fault identification code appears.
Listed below are the faults that can be caused by simple, user-detectable problems.
The boiler is equipped with an advanced self-diagnosis system. In the event of a problem with the boiler,
or system the display will show the fault code. There are some faults that will require the end user to
press RESET (2 - fig. 1); if the boiler fails to start, It is necessary to rectify the fault indicated by the
LED display (faults from 1 to 26); other faults cause temporary shutdown that are automatically reset as
soon as the value comes back within the boiler’s normal working range (faults from 30 to 46).
Example
Boiler failed to light
Make sure that the gas isolation valve on the boiler and on the
gas meter are open.
Press the RESET button (2 Fig. 1).
Fault CureDISPLAY
Before calling the FERROLI Caresafe helpline, check that the problem is not due to there being
no gas or electricity, and that all external controls are wired correctly and calling fo heat.
If the problem remains after two attempts at resetting, contact your nearest FERROLI Caresafe.
For other faults, refer to section 3.4 “Troubleshooting”.

Optimax 25 OV
8
2. INSTALLATION
2.1 General Instructions
This device must only be used for the purpose for which it is specially designed. This unit is desi-
gned to heat water to a temperature below boiling point and must be connected to a heating
system and, compatible with its performance, characteristics and its heating capacity. Any other
use is considered improper.
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 RECOMENDATION OF BS STANDARDS, ANY LOCAL REGULATIONS AND THE RULES OF
COMPEDENT WORKMANSHIP.
Incorrect installation can cause damage or physical injury for which the manufacturer declines any
responsibility.
This appliance must be installed strictly in accordance with these instruc-
tions and regulations:
The Gas Safety Regulations (Installations & Use).
The Local Building Regulations.
The Building Regulations (Part L).
The Buildings Standards (Scotland - Consolidated) Regulations.
British Standards Codes of Practice:
B.S. 5440 Part 1 Flues
B.S. 5440 Part 2 Air supply
B.S. 5449 FORCED CIRCULATION HOT WATER SYSTEMS
B.S. 6798 INSTALLATION OF GAS FIRED HOT WATER BOILERS
B.S. 6891 GAS INSTALLATIONS
B.S. 7671 IEE WIRING REGULATIONS
B.S. 4814 SPECIFICATION FOR EXPANSION VESSELS
B.S. 5482 INSTALLATION OF LPG
B.S. 7593 TREATMENT OF WATER IN DOMESTIC HOT WATER CENTRAL HEATING
SYSTEMS
B.S. 5546 INSTALLATION OF HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
Model Water Bye Laws
B.S. 5955-8 PLASTIC PIPEWORK INSTALLATION
For Northern Ireland the rules in force apply

Optimax 25 OV
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> 600 mm
Minimum Recommended
A
B
D
30 mm
200 mm
15 mm
(via an openable panel)
300 mm
300 mm
C280 mm 300 mm
Table 1
fig. 2
A A
B
DC
2.2 Boiler location
The unit’s combustion circuit is sealed off from
the installation room. The installation room
must be sufficiently well ventilated to prevent
any dangerous conditions from forming in the
event of even slight gas leakage. This safety
standard is required by the EEC Directive no.
90/396 for all gas units, including those with a
so-called sealed chamber.
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.
The boiler is design to be installed on a solid
wall. The wall fixing must ensure a stable and
effective support for the appliance, using the
bracket and fixings supplied.
If the unit is enclosed in cupboard or moun-
ted alongside, there must be space for normal
maintenance work. Fig. 2 and tab. 1 give the
minimum clearances to leave around the unit.

Optimax 25 OV
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fig. 3
50
50 45
35
2
1 4
3
95 120 185
164
400
201 35
50 35
110,5
2.3 Water connections
The heating capacityof the unit shouldbe previouslyestablished
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 flow and return pipes follow a path where air pockets
could form in certain places, it is advisable to install air vents
at these points. Also, install a drain plug at the lowest point in
the system to allow its complete emptying, when required.
The temperature differential between the flow and the return
to the boiler should not exceed 20° C (11° recommended).
Do not use the water system pipes to earth electrical
appliances.
Before installation, thoroughly clean all the pipes of the system
to remove residues or impurities that could affect the unit’s
operation. Flush system in accordance with BS 7593.
Make the connections to the corresponding tappings as shown
in fig. 3.
Key
1 CH flow (22 mm with compression coupler fitted)
2 Gas inlet (22 mm with isolation valve)
3 Condense outlet
4 CH return (22 mm with compression coupler fitted)
It is advisable to install anti-tamper isolation valves between the boiler and heating system allowing
the boiler to be isolated from the system if necessary.