Riello TAU 350 N Service manual

cod. 20138616 rev. 5 03/2019
TAU 115-350 N OIL PRO
EN INSTALLATION, TECHNICAL ASSISTANCE SERVICE AND SYSTEM MANAGEMENT MANUAL

2
RANGE
MODEL CODE
TAU 115 N OIL PRO 20124420
TAU 150 N OIL PRO 20124421
TAU 210 N OIL PRO 20124423
TAU 270 N OIL PRO 20124424
TAU 350 N OIL PRO 20124425
ACCESSORIES
For a complete list of accessories and details of their compatibil-
ity, refer to the Catalogue.
ENGLISH
Dear Customer,
Thank you for choosing a Rboiler. You have purchased a
modern, high efciency, quality product that is designed to
give dependable and safe service and to provide comfort in
the home for many years to come. Arrange for your boiler to be
serviced regularly by an authorised Technical Assistance Service
R. Their personnel are specially trained to keep your boiler
efcient and cheap to run. They also stock any original spare
parts that might be required.
This instruction manual contains important instructions and
precautions that must be observed to ensure the efcient func-
tioning of your TAU N OIL PRO boiler.
Please accept our renewed thanks for your purchase
Riello S.p.A.
CONFORMITY
RTAU N OIL PRO boilers conform to:
−Directive 92/42/EEC on efciency requirements
−Electromagnetic Compatibility Directive 2014/30/EU
−Low Voltage Directive 2014/35/EU
−Ecodesign Directive 2009/125/CE for energy-related prod-
ucts
−Delegated Regulation (EU) N. 813/2013.

3
This manual, Code 20138616 - Rev. 5 (03/2019)
comprises 32 pages.
Contents
CONTENTS
The following symbols are used in this manual:
9 CAUTION! = Identies actions that require caution and
adequate preparation.
0 STOP! = Identies actions that you MUST NOT do.
Thismanual,Code
-Rev.
comprises
pages.
1 GENERAL INFORMATION ............................4
1.1 General Safety Information ......................4
1.2 Precautions..................................4
1.3 Description of the appliance .....................5
1.4 Control panels................................6
1.5 Recommended burners and technical specications ..7
1.6 Identication ................................9
2 SYSTEM MANAGER ................................10
2.1 Putting into service ........................... 10
2.2 Preparing for extended periods of disuse ...........11
2.3 Cleaning ....................................11
2.4 Maintenance.................................11
2.5 Useful information ........................... 12
3 INSTALLER .........................................13
3.1 Unpacking the product ........................ 13
3.2 Overall dimensions and weights ................. 14
3.3 Handling................................... 14
3.4 Installation premises ......................... 15
3.5 Water in central heating systems................. 16
3.6 Water connections ........................... 18
3.7 Condensate evacuation........................20
3.8 Neutralising the condensate ....................20
3.9 Discharge of combustion products ............... 22
3.10 Door hinges ................................23
3.11 Changing the direction of door opening ...........23
3.12 Removing the hinge assembly "B" ...............25
3.13 Earth connection ............................25
3.14 Fitting the casing panels .......................26
4 TECHNICAL ASSISTANCE SERVICE..................27
4.1 Preparing for initial startup..................... 27
4.2 Initial startup ............................... 27
4.3 Checks during and after initial start-up ...........28
4.4 Maintenance................................28
4.5 Cleaning the boiler ...........................29
4.6 Troubleshooting ............................. 31

4
GENERAL INFORMATION
GENERAL INFORMATION
1 GENERAL INFORMATION
1.1 General Safety Information
9 The boiler is delivered in separate crates. Check that it is
complete, undamaged and as ordered as soon as you re-
ceive it. Report any discrepancies or damage to the dealer
who sold it.
9 This product must be installed by a legally qualied heat-
ing engineer. On completion of the installation, the install-
er must issue the owner with a declaration of conformity
conrming that the installation has been completed to the
highest standards in compliance with the instructions pro-
vided by Rin this instruction manual, and that it con-
forms to all applicable laws and standards.
9 This product must only be used for the purpose for which it
is designed and made, as specied by R. Rdeclines
all responsibility, contractual or other, for damage to prop-
erty or injury to persons or animals caused by improper in-
stallation, adjustment, maintenance or use.
9 If you notice any water leaking from the boiler, disconnect it
immediately from the mains electricity supply, shut off the
water supply, and notify your local R’s Technical Assis-
tance Service or a qualied heating engineer immediately.
9 Periodically check that operating pressure in the water cir-
cuit is over 1 bar but below the maximum limit specied for
the boiler. If this is not the case, contact Technical Assistance
Service R or a professionally qualied heating engineer.
9 If the boiler is not going to be used for an extended pe-
riod of time, contact R’s Technical Assistance Service or
a qualied heating engineer to have it prepared for shut-
down as follows
−Switch the boiler OFF at the control panel
−Turn the main system switch "off"
−Close the fuel cock and heating circuit water cock
−Drain the central heating circuit if there is any risk of
freezing.
9 The boiler must be serviced at least once a year.
9 This instruction manual is an integral part of the boiler. It
must be kept safe and must ALWAYS accompany the boiler,
even if it is sold to another owner or transferred to another
user or to another installation. If you damage or lose this
manual, order a replacement immediately from your local
R’s Technical Assistance Service.
1.2 Precautions
The operation of any appliance that uses fuel, electrical power
and water demands that a number of fundamental safety pre-
cautions be respected:
0 It is forbidden to use electrical devices or equipment, such
as switches, appliances, etc. if there is a smell of gas or un-
burnt products. If so:
−Ventilate the room, opening doors and windows
−Close the fuel shut-off cock
−Report the fault immediately to the R's Technical As-
sistance Service or a professionally qualied heating en-
gineer.
0 Do not touch the boiler while barefoot or wet.
0 Never clean or service the boiler without rst disconnect-
ing it from the mains electricity supply by turning the main
power switch and the control panel switch OFF.
0 Do not tamper with or adjust the safety or control devices
without prior authorisation and instructions from the man-
ufacturer.
0 Do not plug or block the condensate drain outlet.
0 Never pull, disconnect, or twist the electrical cables coming
from the appliance even if it is disconnected from the mains
electricity supply.
0 Do not obstruct or restrict the vents in the room where the
boiler is installed. Adequate ventilation is essential for cor-
rect combustion.
0 Do not expose the boiler to the elements. It is designed to
work indoors.
0 Do not switch the boiler off if outdoor temperature drops
below ZERO (risk of freezing).
0 Do not store containers of ammable substances in the
room where the boiler is installed.
0 Do not allow children or persons with reduced physical,
sensorial or mental abilities or with insufcient experience
and knowledge to operate this system without proper su-
pervision from the person responsible for its safe use.
0 Do not dispose of packaging material into the environment,
or leave it within the reach of children, since it can become
a potential hazard. Dispose of packaging material in com-
pliance with applicable legislation.
Generalinformation

5
GENERAL INFORMATION
GENERAL INFORMATION
1.3 Description of the appliance
TAU N OIL PRO R steel boilers are triple ue pass, condensing
boilers for installation in a boiler room. While they are designed
primarily for central heating purposes, in conjunction with a
suitable storage cylinder they can also be used to produce do-
mestic hot water.
They are suitable to operate with fuel oil burners.
The parts of the boiler that are in contact with combustion prod-
ucts are made entirely of highly alloyed stainless steel, capable
of providing the best possible resistance to corrosion caused by
acid condensate.
The boiler has been designed with the combustion chamber at
the top and the smooth pipe tube bundle at the bottom to opti-
mise heat exchange and energy efciency and to maximise the
condensing effect.
The boiler has a high total water content which is differential-
ly distributed between its top and bottom sections. This al-
lows outgoing water to reach the set temperature quickly while
maintaining the condensing effect and the water heating time
around the tube bundle for as long as possible.
TAU N OIL PRO boilers feature lightly pressurised combustion
chambers for a smoother burner action, and high temperature
resistant, stainless steel turbulators inside the tube bundle for
maximum burner efciency.
The boiler body is thoroughly insulated with a layer of high den-
sity glass wool.
The paint nished external panelling is also internally insulated
with a layer of high density glass wool.
The boiler’s front door and the ue gas chamber can be opened
completely to facilitate the inspection, maintenance and clean-
ing of internal parts and to speed up servicing in general.
The front door can open in either direction and can be opened
without removing the burner. The door is factory tted with
hinges on the left, but these can be reversed if necessary to suit
individual installations.
3
2
1
4 5
678
10
9
11
12
13
14
15
16
19
18
17
1 Burner
2 Flame inspection window with pressure meas-
urement tting
3 Door
4 Casing
5 Outlet
6 Safety device tting
7 Heating return (high temperature)
8 Heating return (low temperature)
9 Blind plug
10 Instrument bulb/sensor sockets
11 Combustion chamber
12 Flue gas exhaust
13 Flue gas box
14 Inspection window
15 Condensate outlet
16 Boiler drain
17 Turbulators
18 Flue gas pipes
19 Second ue pass

6
GENERAL INFORMATION
GENERAL INFORMATION
1.4 Control panels
The Rcontrol panels that can be used with RTAU N OIL PRO
steel boilers are listed below. These control panels cater for all
the needs of the heating system and of all the devices installed
in it.
TECH CLIMA TOP for central heating (1 direct zone and 2 mixed
zones) and domestic hot water production with a single stage,
two stage, or modulating burner. Also for controlling solar heat-
ing system and cascaded boiler systems.
TECH CLIMA COMFORT for central heating (1 direct zone and 1
mixed zone) and domestic hot water production with a single
stage burner. Also for controlling solar heating system and cas-
caded boiler systems.
TECH CLIMA MIX for controlling 1 additional mixed zone.

7
GENERAL INFORMATION
GENERAL INFORMATION
1.5 Recommended burners and technical specications
BURNERS TAU N OIL PRO ACCESSORIES KIT
MODEL CODE 115 150 210 270 350 BURNER PLATE
BG7.1D 20015696 x(R)
RL 25 BLU 20116089 x(R) x(R)
RL 35 BLU 20116062 x x(R)
RL 42 BLU 20027567 x(R)
(R) Reference burner used during performance qualication tests to derive the technical data declared.
9 See the instruction manual provided with the burner:
−Burner installation
−Electrical connections
−Burner adjustments.
9 To assemble/disassemble the burners equipped with recirculation tube, it might be necessary to remove the latter before car-
rying out such operations (strictly comply with the use and maintenance manual of the burner).

8
GENERAL INFORMATION
GENERAL INFORMATION
Technical specications
DESCRIPTION TAU N OIL PRO
115 150 210 270 350
Device type Condensing boiler for central heating
B23
Fuel All oils
Device category See Burner
Rated heat input (Qmax) HCV (LCV) 112
(115)
159
(150)
223
(210)
286
(270)
371
(350) kW
Useful (rated) heat output 112 146 205 264 343 kW
Rated maximum useful heat output (80/60°C) P4 112,2 146,4 205,2 264,3 343,7 kW
30% heat output with return at 30°C (P1) 33,7 43,9 61,6 79,3 103,1 kW
Seasonal energy efciency ηs94 93 94 94 94 %
Efciency at rated heat input in high temperature
mode η4 (80-60°C) HCV (LCV)
92
(97,6)
92
(97,6)
92,1
(97,7)
92,3
(97,9)
92,6
(98,2) %
Efciency at 30% rated heat input in low tempera-
ture mode η1 with return at 30°C (HCV)
98,8
(104,8)
98,7
(104,7)
98,6
(104,6)
98,4
(104,4)
98,1
104,1) %
Losses from stack for sensible heat (Qmax) 1,7 1,7 1,7 1,5 1,5 %
Losses from casing with burner on 0,3 0,3 0,3 0,5 1,0 %
Constant pressure drop 300 300 420 540 700 W
Flue gas temperature (∆T) < 45÷75 (*) °C
Emissions at max. heat input Nox (0% O2) <120 (**) mg/kWh
Flue gas mass ow rate (Qmax) 0,05 0,07 0,09 0,12 0,15 kg/sec
Furnace pressure 2,2 2,0 2,7 3,2 4,6 mbar
Furnace volume 172 172 172 241 279 dm3
Tot. volume of ue gas side 246 272 292 413 482 dm3
Heat exchange surface area 7,0 8,2 10,4 13,0 16,3 m2
Volumetric heat load (Qmax) 669 872 1221 1120 1254 kW/m3
Specic heat load 16 18 20 21 21 kW/m2
Maximum condensate production 11,0 18,4 27,4 31,9 40,9 l/h
Maximum working pressure 6bar
Maximum permitted temperature 110 °C
Maximum operating temperature 95 °C
Pressure drop ∆T 10°C 50,0 43,2 36,0 54,0 46,4 mbar
Pressure drop ∆T 20°C 12,5 11,3 10,2 16,3 13,4 mbar
Water capacity 375 360 323 495 555 l
Consumption at full load (Elmax) 390 650 650 800 800 W
Consumption at part load (Elmin) 117 195 195 240 240 W
Electrical consumption in standby mode (PSB) 20 20 20 20 20 W
(*) Depends on return temperature (30-60°C).
(**) Value according to EN267 (nitrogen content in light oil =140mg/kg).
9 Values obtained with reference burners (R) used for the performance verication tests (see burner pairing table), calibrated with
CO2 = 12,5%.
9 WARNING: If coupled with low NOx emission diesel burners compliant with the 2018 ErP Directive, the generators are able to
operate with nitrogen oxide emissions below the limits required by said Directive.

9
GENERAL INFORMATION
GENERAL INFORMATION
IMPORTANT NOTES FOR BURNER INSTALLATION
Before xing the burner to the boiler, make sure that:
−The door opens the right way (see the relevant sections
for details on how to reverse the door)
−The length (L) of the burner xing bolts is less than (S),
i.e. the total depth of the seal, plates and washer. Longer
bolts can cause the door to warp, compromising its
ability to seal the boiler hermetically and permitting
the release of combustion fumes.
To ensure correct burner installation, also refer to the burner’s
own manual.
L < S
S
L
If you are installing a new boiler but re-using an old burner,
always perform the following checks:
−Make sure that the performance of the old burner is ad-
equate for the requirements of the boiler
−Make sure that the length and diameter of the burner
nozzle are as specied in the following table.
9 When you nish installing the burner in the boiler, ll the
gap between the burner’s blast tube and the refractory ma-
terial in the door with the ceramic insulation (A) supplied
with the boiler.
A
Ø
L
TAU N OIL PRO
115 150 210 270 350
Burner head
L min. (mm) 110 110 170 180 180
Hole in door
Ø (mm) 162 162 162 180 180
0 Do not re-use old burners if their blast tube lengths are be-
low those specied in the table.
1.6 Identication
The products are identied by:
Serial number plate
This is located on the boiler body and species the serial num-
ber, model, and furnace power.
Data plate
This lists the technical specications and performance of the
product. It comes inside the documentation envelope. On com-
pletion of the installation you MUST apply it in a clearly visible
position at the top of one of the side panels. If you damage
or lose this label, order a replacement immediately from R's
Technical Assistance Service.
9 If these plates or any other means of clearly identifying the
product are defaced, removed or lost, proper installation
and servicing may be rendered difcult.
23270000581
WEEK OF
MANUFACTURE
CALDAIA IN ACCIAIO
Modello Matricola
Codice
Code
Anno fabbricazione Tipo
Type
Portata term. Pot. utile
Pres. Max esercizio
Aliment. elettrica
kW
T°Max ammessa
Contenuto acqua
°C
l
Combustibile utilizzato : TUTTI I GAS / GASOLIO
max (Hi)
Qmax
60°/80°
P
PMS
Pressione focolare
kW
pn
PER CATEGORIA COMBUSTIBILE
E PAESI DI DESTINAZIONE VEDI ETICHETTA BRUCIATORE
Portata term. min (Hi)
QkW Pot. utile kW
Tmax
m²
Superficie di scambio
mbar
RIELLO S.p.A.
Via Ing.Pilade Riello 7
37045 Legnago (VR) - ITALY
066940IE
STEEL BOILER
Model Serial number
Codice PIN
PIN number
Year of manufacture
Max. heat input
Min. heat input
Furnace pressure
Max. operating
pressure
T°Max permitted
Max. useful
heat output
60°/80°
P
min
heat output
Min. useful
Water capacity
Heat exchange
surface area
VEDI QUADRO ELETTRICO - SEE ELECTRIC CONTROL PANEL
Collegamento di terra obbligatorio - Obligatory ground connection
Fuel : GAS / OIL
FOR FUEL TYPE COUNTRY
OF DESTINATION SEE BURNER DATA PLATE
Power supply
Pa
k
Matricola
Modello
Pres. Max esercizio
Portata term. Qmax (Hi)
PMS
kW
RIELLO S.p.A.
Via Ing.Pilade Riello 7
37045 Legnago (VR) - ITALY
Serial no.
Model
Max.operating press.
Max. heat inpt
COMBUSTIBILE UTILIZZATO / FUEL: GAS, GASOLIO / GAS, OIL
Pa
k

10
SYSTEM MANAGER
SYSTEM MANAGER
2 SYSTEM MANAGER
2.1 Putting into service
Have R’s Technical Assistance Service start up your RTAU
N OIL PRO boiler for the rst time. Once this has been done, the
boiler can be left to function automatically.
Under certain circumstances, such as after long periods of dis-
use, the service engineer responsible for the boiler may need
to re-start it without involving the Technical Assistance Service.
To do so, perform the following checks and operations:
−Check that the gas cock and heating water cock are open
−While the system is still cold, check that working pressure
in the central heating circuit is over 1 bar but below the
maximum limit specied for the boiler
−Since the control panel incorporates a temperature con-
trol function, make sure that the control panel is switched
on
−Adjust the timer thermostat (if installed) or the tempera-
ture control to the desired temperature (~20° C)
−Turn the boiler’s mains power switch ON
−Turn the control panel power switch ON and make sure
that the green power indicator lights
−Make the settings as instructed in the instruction manual
for your control panel.
The burner should now ignite and remain in operation until the
set temperature is reached.
The burner will then switch off and on automatically to main-
tain the set temperature without further operator action.
If any ignition faults or malfunctions occur, the burner performs
a “LOCKOUT SHUTDOWN”. This is shown by the red button light on
the burner and by the warning light on the control panel.
9 If a “LOCKOUT SHUTDOWN” occurs, wait about 30 seconds be-
fore resetting the burner.
To reset the burner, press the red button light on the burner and
wait until the ame ignites.
Repeat this operation 2-3 times at the most. If the problem per-
sists after that, call R’s Technical Assistance Service.
Systemmanager

11
SYSTEM MANAGER
SYSTEM MANAGER
2.2 Preparing for extended periods of disuse
If the boiler is not going to be used for an extended period of
time, perform the following operations:
−Turn the control panel power switch OFF and make sure
that the green power indicator goes out
−Turn the main system switch "off"
−Close the fuel cock and heating circuit water cock
−Drain the central heating circuit if there is any risk of
freezing.
9 Contact your local RTechnical Assistance Service if you
encounter any problems in completing the above proce-
dure.
2.3 Cleaning
Use a cloth damped in soapy water to clean the boiler’s external
casing.
To remove stubborn marks, use a cloth damped in a 50% mix
of water and denatured alcohol or a suitable cleaning product.
Carefully dry after cleaning.
0 Do not use abrasive cleaning pads or powder detergents.
0 Never clean the boiler without rst disconnecting it from the
mains electricity supply by turning the mains power switch
and the control panel switch OFF.
9 The combustion chamber and ue pipes must be cleaned
periodically by the manufacturer’s Technical Assistance Ser-
vice or by a qualied heating engineer.
2.4 Maintenance
Please remember that THE PERSON RESPONSIBLE FOR SYSTEM MAN-
AGEMENT MUST ENSURE THAT PROFESSIONALLY QUALIFIED HEATING
ENGINEERS UNDERTAKE PERIODIC MAINTENANCE AND COMBUSTION
EFFICIENCY MEASUREMENTS.
R’s Technical Assistance Service is qualied to satisfy these
legal requirements and can also provide useful information on
MAINTENANCE PROGRAMMES designed to guarantee:
−Greater safety
−Compliance with applicable legislation
−Freedom from the risk of nes in the event of spot checks.
Regular maintenance is essential for the safety, efciency and
durability of the boiler.
Servicing is a legal requirement and must be performed at least
once a year by a professionally qualied heating engineer.

12
SYSTEM MANAGER
SYSTEM MANAGER
2.5 Useful information
Seller:...............................................................................
Mr.: ..................................................................................
Address: ...........................................................................
Tel.:..................................................................................
Technical Assistance Service: ..............................................
Mr.: ..................................................................................
Address: ...........................................................................
Tel.:..................................................................................
Installer:...........................................................................
Mr.: ..................................................................................
Address: ...........................................................................
Tel.:..................................................................................
Date Work done
Fuel oil supplier: ...............................................................
Mr.: ..................................................................................
Address: ...........................................................................
Tel.:..................................................................................
Date Quantity
supplied Date Quantity
supplied Date Quantity
supplied Date Quantity
supplied

13
INSTALLER
INSTALLER
3 INSTALLER
3.1 Unpacking the product
The TAU N OIL PRO boiler is supplied in two separate packages.
1 BOILER BODY CRATE to which is attached the documentation
envelope (A) containing:
−Instruction manual
−Data label (to be applied to the panelling on completion
of the installation)
−Hydraulic test certicate
−Bar code labels
−Ceramic insulation (B)
−Cleaning brush (C).
9 The instruction manuals are an integral part of the boiler,
therefore we recommend to read and keep them with care.
A
C
B
2 PANELLING CRATE, complete with assembly accessories, pro-
tected by cardboard packaging and a wooden crate.
9 For the boiler to function correctly, it must be connected to a
Rcontrol panel and dedicated control accessories.
Installer

14
INSTALLER
INSTALLER
3.2 Overall dimensions and weights
A40 120 L1
L
150
D
H1
H
B 161
DESCRIPTION TAU N OIL PRO
115 150 210 270 350
A - Base width 690 690 690 750 750 mm
B - Width 760 760 760 820 820 mm
L - Length 1455 1455 1455 1630 1830 mm
L1 - Base depth 1295 1295 1295 1470 1670 mm
H - Height of water ttings 1315 1315 1315 1450 1450 mm
H1 - Boiler height 1300 1300 1300 1437 1437 mm
D - Height of burner plate 925 925 925 1030 1030 mm
Weight of boiler 480 510 530 677 753 kg
Weight of casing 50 50 50 60 70 kg
3.3 Handling
TAU N OIL PRO R steel boilers are tted with lifting attach-
ments. Take great care when moving them and only use lifting
equipment of adequate capacity.
Remove the transport straps and remove the wooden pallet be-
fore positioning the boiler.
9 Wear suitable personal protective equipment and use suit-
able safety devices.

15
INSTALLER
INSTALLER
3.4 Installation premises
RTAU N OIL PRO steel boilers must be installed in a dedicated
boiler room, with adequately sized vents, in compliance with
applicable laws and standards.
If at all possible, the boiler should be installed on a raised base
to stop the burner fan sucking up dust and to facilitate installa-
tion of a condensate drain system.
The boiler condensate drain must be located above the height of
the lid of the system’s condensate neutraliser.
The fuel oil supply line must be made in such a way as to allow
both panelling disassembly and door opening with burner in-
stalled.
9 In Belgium, boilers must be installed according to standards
NBN D51.003, NBN D30.003, NBN B61.002 (heat output < 70
kW), and NBN B61.001 (heat output >70 kW).
9 When installing the boiler, allow sufcient space around it
to access all safety and control devices and to permit easy
maintenance.
0 Do not install the boiler outdoors. It is not designed to work
outdoors and is not tted with the necessary automatic an-
ti-frost systems to do so.
≥1 m
≥1 m ≥1 m
L
≥L
H1
B
~ 0,1 m
DESCRIPTION TAU N OIL PRO
115 150 210 270 350
B - Width 750 750 750 850 850 mm
L - Length 1350 1350 1350 1620 1820 mm
H1 - Overall height (boiler + base) 1420 1420 1420 1540 1540 mm

16
INSTALLER
INSTALLER
3.5 Water in central heating systems
INTRODUCTION
Water used in central heating systems MUST be suitably treated
to ensure the correct functioning of those systems and to guar-
antee an extended working life for boilers and all other system
components. This applies not only to existing systems but to
newly installed systems too.
Sludge, lime-scale and pollutants present in the water can cause
permanent damage to the heating unit, also within a short time
and regardless of the quality standards of the materials used.
Contact the Technical Assistance Service for any further informa-
tion on type and use of additives.
9 Always conform to the standards and legislation applicable
in the country of installation.
WATER IN CENTRAL HEATING SYSTEMS.
INSTRUCTIONS FOR THE DESIGN, INSTALLATION AND MANAGEMENT
OF CENTRAL HEATING SYSTEMS.
1. Chemical and physical characteristics of water
The chemical and physical characteristics of water used in cen-
tral heating systems must conform to the requirements of EN
14868 standard and to the following tables:
STEEL BOILERS
with furnace power < 150 kW
Initial lling
water
Regular
service water
(*)
ph 6-8 7,5-9,5
Hardness °fH < 10° < 10°
Electrical
conductivity μs/cm < 150
Chlorides mg/l < 20
Sulphides mg/l < 20
Nitrides mg/l < 20
Iron mg/l < 0,5
STEEL BOILERS
with furnace power > 150 kW
Initial lling
water
Regular
service water
(*)
ph 6-8 7,5-9,5
Hardness °fH < 5° < 5°
Electrical
conductivity μs/cm < 100
Chlorides mg/l < 10
Sulphides mg/l < 10
Nitrides mg/l < 10
Iron mg/l < 0,5
(*) values for water in system after 8 weeks of functioning
General note on water used to top up systems:
−If softened water is used to top up a system, 8 weeks of
functioning after topping up, verify that the water in the
system respects the above limits, in particular for electri-
cal conductivity
−This check is not necessary if demineralised water is used
to top up the system.
2. Central heating systems
9 Do not use automatic lling devices to add water to central
heating systems. Use a manual device instead and record
top-ups in the system service book.
9 If there are more than one boiler, they must all be put into
service either contemporarily or with a very low rotation
time during the initial period of service, so as to evenly dis-
tribute the limited quantity of initial lime-scale.
9 A ushing cycle must be programmed after the plant has
been installed to ush out any installation debris.
9 Water used to ll a system for the rst time and water used
to top it up must always be ltered (using synthetic or metal
mesh lters with a ltration rating of no less than 50 mi-
crons) to prevent sludge from forming and triggering de-
posit corrosion.
9 The heating system must be ushed out and cleaned with
good workmanship before lling up the existing systems.
The boiler may not be lled until after the heating system
has been ushed out.
2.1 New central heating systems
The system must be lled up slowly the rst time; once it is lled
and the air expelled it should never need to be topped up again.
Systems should also be operated at maximum working tem-
perature the rst time they are started up, in order to facilitate
de-aeration. (Gas is not released from the water at low temper-
atures).
2.2 Reconditioning old central heating systems
If a boiler has to be replaced, do not rell the entire central
heating circuit if the quality of water in it conforms to require-
ments. If the quality of water fails to conform to requirements,
either recondition the old water or separate the water circuits
(water in the boiler circuit must conform to requirements).
3. Corrosion
3.1 Deposit corrosion
Under-deposit corrosion is an electrochemical process, due to
the presence of sand, rust, etc., inside the mass of water. These
solid substances generally deposit on the bottom of the boiler
(sludge), on tube and pipe heads or in the gaps between pipes
and tubes.
Micro-corrosion phenomena may be triggered off owing to the
difference in electrochemical potential coming to be created
between the material in contact with the impurity and the sur-
rounding one.
3.2 Stray current corrosion
Corrosion from stray currents can occur due to the differing elec-
trical potentials between water in the boiler and the metallic
mass of the boiler or piping. This process leaves unmistakeable
traces i.e. small regular conical holes.
9 All metallic parts should be grounded by an efcient earth
cable for this reason.

17
INSTALLER
INSTALLER
4. Eliminating air and gas from central heating systems
If oxygen enters a circuit continuously or even intermittently
(e.g. in under-oor heating systems whose pipes are not pro-
tected by impermeable synthetic sheaths, in circuits with open
expansion vessels, or in circuits that require frequent top-ups)
always separate the boiler’s water circuit from the central heat-
ing circuit.
Mistakes to avoid and precautions.
From what we have seen it is therefore important to avoid two
factors possibly leading to the above mentioned processes i.e.
contact between air and water in the installation and regular
topping up with fresh water.
To eliminate contact between air and water (and to prevent the
latter from becoming oxidized), it is necessary:
−For the expansion system to be a closed vessel type, cor-
rectly scaled and with the correct pre-loading pressure
(to be regularly checked)
−For the installation to always be at a higher pressure
than that of the atmosphere at any point (comprising the
pump suction side) and under all running conditions (all
the water sealing and couplings in the installation are
designed to resist pressure towards outside, but not for
depression)
−That the installation will not be made with materials per-
meable to gas (e.g. plastic pipes for oor systems without
anti-oxygen barrier).
9 Lastly we would remind you that the warranty does not cov-
er breakdowns incurred by the boiler due to deposits and
corrosion.

18
INSTALLER
INSTALLER
3.6 Water connections
RTAU N OIL PRO boilers are designed and made for use in central heating installations, but can also be used for domestic hot
water production if connected to a suitable storage cylinder. Water ttings are as specied in the following table.
MM
7
6
5
H
A
N
B
8
F
E D C
2
3
4
1
76
I
G
L
O
DESCRIPTION TAU N OIL PRO
115 150 210 270 350
1 - Heating ow (*) 65 65 65 65 80 DN
2 - Heating return 1 (Low Temperature) (*) 65 65 65 65 80 DN
3 - Heating return 2 (High Temperature) (*) 50 50 50 50 65 DN
4 - Safety device tting 1” 1/4 1” 1/4 1” 1/4 1” 1/4 1” 1/4 Ø ”- DN
5 - Boiler drain tting 1” 1” 1” 1” 1” Ø”
6 - Condensate drain tting 1” 1” 1” 1” 1” Ø ”- DN
7 - Flue gas exhaust tting 160 200 200 250 250 Ø mm
8 - Instrument bulb/probe sockets 3 x 1/2” 3 x 1/2” 3 x 1/2” 3 x 1/2” 3 x 1/2” n° x Ø ”
A - Distance from burner head to heating ow outlet 300 300 300 300 315 mm
B - Distance from heating ow outlet to return 1 885 885 885 1050 1235 mm
C - Distance between heating returns 1 & 2 200 200 200 300 250 mm
D - Distance between heating return 2 and safety
device tting 285 285 285 300 450 mm
E - Distance between heating ow outlet and safety
device tting 400 400 400 450 535 mm
F - Distance between heating return 1 and ue gas
outlet 200 200 200 225 225 mm
G - Height of condensate drain 152 152 156 156 156 mm
H - Height of boiler anges 1340 1340 1340 1450 1450 mm
I - Height of ue gas outlet 505 505 505 535 535 mm
L - Height of boiler drain tting 60 60 60 60 60 mm
M - Boiler centreline 345 345 345 375 375 mm
N - Distance from burner head to door 110 110 110 120 120 mm
O - Distance from Boiler drain tting 132 132 132 137 137 mm
(*) All anged connections are PN6 according to EN 1092-1.

19
INSTALLER
INSTALLER
TYPICAL INSTALLATION SCHEMATIC
Direct systems
11
HEATING FLOWHEATING
RETURN
67
3
4
5
3
3
4
5
3
DHW USER
POINTS
14
INLET
315 16 3
13
9
6
12
310 15 3
3
2
3
4
5
3
3
2
3
18
19 19
8
17
3
20 1
Direct and mixed systems
8
11
HEATING FLOW
HEATING
RETURN
BT (*)
HEATING
RETURN
AT (*)
67
3
4
5
3
3
4
5
3
DHW USER
POINTS
14
INLET
315 16 3
13
9
6
12
310 15 3
3
2
3
4
5
3
3
2
3
17
18
19 19
21
3
20
3
3
2
1
1 Boiler RTAU N OIL PRO
2 Central heating system manifolds
3 Disconnect valves
4 System pumps
5 Non-return valves
6 Automatic vent valve
7 Boiler safety valve
8 Boiler drain cock
9 Storage cylinder safety valve
10 System lling cock
11 CH expansion vessel
12 Remote controlled water tank (R7200)
13 Storage cylinder drain cock
14 DHW expansion vessel
15 Water softener lter
16 Pressure reducer
17 Siphon
18 Condensate outlet
19 Drain
20 Water supply/top-up counter
21 Servo valve
(*) AT= High Temperature BT= Low Temperature

20
INSTALLER
INSTALLER
3.7 Condensate evacuation
TAU N OIL PRO condensing boilers produce a ow of conden-
sate that varies according to operating conditions. The maxi-
mum hourly production of condensate is shown in the technical
specications table for each individual model.
The condensate outlet must be sized according to this value and
at no point must the diameter be less than the diameter of the
boiler condensate discharge (7).
In order to avoid the release of combustion products in the ther-
mal room, it is necessary to insert the trap supplied with the
boiler in the condensation drain path. The connecting pipes be-
tween the boiler, siphon and waste water drain pit must be laid
at a minimum down slope of 3° and must be installed in such a
way as to prevent any build-up of.
9 Check and clean the condensation drain line on a yearly ba-
sis.
9 The connection to the waste water drain pit must be made
in compliance with national and local legislation and
standards.
≥3°
≥3°
7
3.8 Neutralising the condensate
NEUTRALISATION KIT N2-N3
N2-N3 neutralisation units are designed for systems with boiler
condensate drain pits located at a lower level than the boiler
condensate drain tting. These neutralisation units do not re-
quire any electrical connections.
Type N2 N3
Maximum ow rate of
neutralised condensation
(litres/hour)
54 180
Dimension (mm) 420x300x240 640x400x240
Q.ty of granulate 25 kg 50 kg
Fitting Ø 1" 1" 1/2
A
B
C
The inlet tting (A) of the N2 neutralisation unit (the lower t-
ting) must be connected to the boiler condensate drain tting
using the exible hose (C) supplied. This condensate drain hose
is specially made to prevent combustion fumes escaping into
the atmosphere.
The outlet tting (B) of the neutralisation unit (the top tting)
must be connected to the boiler room’s waste water drain pit
using another section of exible hose (not supplied).
9 The boiler room’s condensate drain pit must be located at
a lower level than the tting (B) on the neutralisation unit.
9 The connection pipes used must be as short and straight as
possible and corrosion-resistant. Any curves or sharp bends
can lead to the hoses becoming clogged and can therefore
prevent proper condensate discharge.
If it is necessary to neutralise condensation produced in the
chimney, we recommend to connect the condensation drains of
boiler and chimney using a tee connector and then get them to
the neutraliser inlet.
9 Make sure that you tighten the hose clamps sufciently.