Presentation; General Warnings; Certification; Technical And Constructional Specifications, Dimensions - Ferroli PREXTHERM RS3 Mode D'emploi

1. PRESENTATION

Dear Customer,
Thank you for having chosen a PREXTHERM
RS3 boiler.
This manual has been prepared to provide you
with information, warnings and suggestions on

2. GENERAL WARNINGS

- This instruction manual is an integral part of
the product, and provides important instruc-
tions for installation, operation and maintenance.
- This appliance must only be used for the pur-
poses it has been specifically designed for.
- This appliance is used to heat water to
below-boiling temperatures at atmospheric
pressure, and must be connected to a cen-
tral heating and/or domestic hot water
distribution system, according to its cha-
racteristics, performance and heat output.
- Before installation, check that the boiler has
not been damaged due to handling and
transport.
- The boiler must be installed in compliance
with the standards in force, by suitably quali-
fied personnel.

3. CERTIFICATION

The CE Mark attests that Ferroli appliances
conform to the requirements specified in the
applicable European directives.
4. TECHNICAL AND CONSTRUCTIONAL
SPECIFICATIONS, DIMENSIONS

4.1 Description of the appliance

The construction of the PREXTHERM RS3
series boilers guarantees high output and effi-
ciency at low flue gas temperatures, thus ensu-
ring reduced polluting emissions.
The appliances are made according to the EN
303 standard, part 1.
The main technical elements of the design are:
- the careful design of the shapes, to ensure an
optimum ratio between the combustion volu-
mes and the heat exchange surfaces
- the choice of materials used, for the long life of
the boiler.
The boilers use pressurised combustion, with
three flue passes, overlapping double plating
with completely cooled furnace on the bottom
part and the tube bundle on the top part, and
featuring turbulators to create a swirling path
that increases the heat exchange by convection.
On leaving the tube bundle, the flue gas enters
the rear chamber and is transferred to the chim-
ney. The boilers are fitted with a door featuring
hinges that can be reversed for opening to the
right or the left, and is adjustable in both height
and depth. The body plating is insulated with a
thick layer of glass wool, and covered with a
further layer of tearproof material. The external
finish consists of painted steel panels. The hoi-
sting hooks are fitted on the top of the plating.
The boilers feature two 1/2" fittings for bulb
sheaths (able to house three bulbs each).
The pre-wired control panel (to be ordered
separately) is located above the boiler, and
the installation, correct use and maintenance of
the boiler. Please therefore read it thoroughly
and keep it with care for future reference.
In your interest, we suggest that you carefully
observe the contents of this manual, so as to
be able to get the most from this high quality
- Before performing any cleaning or maintenan-
ce operations, disconnect the appliance from
the mains power supply.
- Ferroli is not liable for any damage to per-
S.p.A.
sons people and/or things due to errors in
installation, control, maintenance and
improper use.
- The boiler and the corresponding system must
be commissioned by authorised personnel.
- Commissioning is performed in order to check
the correct operation of all the control devices.
- Qualified personnel must be contacted if the
appliance is not used for an extended period.
Standards
The installer must observe the local standards
in force as regards: the choice of the site of
installation of the boiler, the compliance with the
In particular, this appliance conforms to the fol-
lowing EEC directives:
- Gas directive (2009/142/CE)
- Efficiency directive (92/42 EEC)
ensure automatic operation.

4.2 Operating principle

The PREXTHERM RSH boilers are fitted with a
closed cylindrical furnace, in which the flame pro-
duced by the burner is reversed peripherally
towards the front, from where the burned gas
enters the fire tubes. At the outlet, the gas is col-
lected in the smokebox and is then sent to the
chimney. The combustion chamber is always
pressurised during the operation of the burner.
For the pressure values, see the tables on page
16, under the column Flue gas side pressure drop.
The flue and the flue stack fitting must be made
in compliance with the standards and the legisla-
tion in force, using rigid pipes that are resistant to
high temperatures, condensate and mechanical
stress, and are airtight. (Fig. 1)
4.3 Technical specifications - Dimensions -
Water fittings
Key (Fig. 2)
1 Control panel
2 Burner mounting flange
3 Smoke box cleaning door
4 Flame inspection window
T1 Water delivery
T2 Water return
T3 Expansion vessel connection
T4 Discharge/exhaust boiler
T5 Chimney connection
T6 Burner connection
- 15 -
product. The Manufacturer declines all liability
and the warranty will be void in the event
where the instructions described in this
manual are not observed.
required ventilation conditions; the tightness of
the connection to the chimney; the connections
of the fuel lines, electrical systems and any
other relevant safety standards.
Warranty conditions
The warranty is only valid if the standards and
the suggestions for use described in this manual
are observed. Failure to observe such stan-
dards and suggestions will void the warranty.
The warranty excludes all damage due to cor-
rosion from the acidic condensate of the pro-
ducts of combustion or the formation of depo-
sits caused by the use of hard or aggressive
water, as such are solely due to the operation
of the system.
- Low voltage directive 73/23 EEC
(amended by 93/68)
- Electromagnetic compatibility directive 89/336
(amended by 93/68)

4.4 Identification

The boiler can be identified from the:
- Document envelope
This is applied to the door, and contains:
TECHNICAL MANUAL
WARRANTY CERTIFICATE
LABELS WITH BARCODE
RATING LABEL
CONSTRUCTION CERTIFICATE
(certifying that the water pressure tests have
been passed)
- Rating label
This describes the technical specifications
and the performance of the appliance (Fig. 4).
It is included in the document envelope and
MUST BE APPLIED by the installer, when
installation is complete, to the top front part of
one of the side panels of the casing, in a visi-
ble position.
If the label is lost, contact the Ferroli
Technical Service for a duplicate.
Tampering with or the removal or absence of
rating labels or other means enabling the unit to
be identified causes problems during installation
and maintenance.
Key (Fig. 4)
1 Document envelope
GB