Riello TAU 1750 N Service manual

cod. 20172279 rev. 1 11/2020
TAU 1750 ÷ 3000 N
EN INSTALLATION, TECHNICAL ASSISTANCE SERVICE AND SYSTEM MANAGEMENT MANUAL

2
RANGE
MODEL CODE
TAU 1750 N 20162157
TAU 2100 N 20162158
TAU 2600 N 20162159
TAU 3000 N 20162160
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 boiler.
Please accept our renewed thanks for your purchase
Riello S.p.A.
CONFORMITY
RTAU N boilers conform to:
−Directive 92/42/EEC on efciency requirements
−Electromagnetic Compatibility Directive 2014/30/EU
−Low Voltage Directive 2014/35/EU
−Regulation (EU) 2016/426
At the end of its life, the product should
be not be disposed of as solid urban
waste, but rather it should be handed
over to a differentiated waste collection
centre.

3
This manual, Code 20172279 - Rev. 1 (11/2020)
comprises 48 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................................5
1.5 Identication ................................5
1.6 System layout ................................6
1.7 Burner combination ...........................7
1.8 Technical specications.........................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................................... 15
3.4 Installation premises ......................... 16
3.5 Positioning of sensor sockets ....................17
3.5.1 Water-side pressure drop ...................... 18
3.6 Water in central heating systems................. 19
3.6.1 Glycol .....................................20
3.7 Water connections ........................... 21
3.8 Schematic diagram ........................... 22
3.9 Condensate evacuation........................28
3.10 Neutralising the condensate ....................29
3.11 Discharge of combustion products ............... 31
3.12 Door hinges ................................32
3.13 Changing the direction of door opening ........... 32
3.14 Earth connection ............................34
3.15 Fitting the casing panels .......................35
4 TECHNICAL ASSISTANCE SERVICE..................38
4.1 Preparing for initial startup.....................38
4.2 Initial startup ...............................38
4.3 Checks during and after initial start-up ...........39
4.4 Maintenance................................40
4.5 Adjusting the door ...........................40
4.6 Cleaning the boiler ...........................45
4.7 External cleaning ............................46
4.8 Boiler inspection - water-side ..................46
4.9 Troubleshooting ............................. 47

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 R steel boilers are triple ue pass, condensing boilers
for installation in a boiler room. While they are designed pri-
marily for central heating purposes, in conjunction with a suit-
able storage cylinder they can also be used to produce domestic
hot water.
The parts of the boiler that are in contact with combustion
products are made of Titanium stabilized stainless steel, capa-
ble 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 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.
1.4 Control panels
The steel boilers RTAU N can be combined with the control
panels of the RIELLOtech range which take into account the dif-
ferent operating functions, the needs of the heating system and
the various devices used on them.
Note: for additional information, see the Listocatalogo
1.5 Identication
The products are identied by:
Serial number plate
This is located on the boiler body and species the serial
number, model, and furnace power.
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
Data plate
This lists the technical specications and performance of the
product. It comes inside the documentation envelope. On
completion 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.

6
GENERAL INFORMATION
GENERAL INFORMATION
1.6 System layout
TAU N 1750 ÷ 3000
3 4 5 6 7
8
9
15
10
11
14
12
13
1 2
1 Burner
2 Flame inspection window with pressure meas-
urement tting
3 Door
4 Body interior inspection ange
5 Outlet
6 Safety device tting
7 Heating return (high temperature)
8 Combustion chamber
9 Heating return (low temperature)
10 Flue gas box
11 Flue gas exhaust
12 Inspection window
13 Condensate outlet
14 Boiler drain
15 Support surface - maximum load 150 kg

7
GENERAL INFORMATION
GENERAL INFORMATION
1.7 Burner combination
BURNERS TAU N Burner ange Long head
MODEL 1750 2100 2600 3000 Accessory
(compulsory)
Accessory
(compulsory)
Standard GAS (yellow ame)
RS 190/M TL ●
RS 250/M MZ TL ●20164364
RS 310/M MZ ●(2)
RS 410/M MZ ● (1) ●(2)
RS 510/M MZ ● (1) (2)
LOW NOX GAS
RS 200/M BLU TL ●
RS 310/M BLU ●(2)
RS 410 M BLU ● ●
RS 510 M BLU ● (1) (2)
RS 200/E BLU ● (1) (2)
RS 310/E BLU ●(2)
RS 410/E BLU ● ● (2)
RS 510/E BLU ● (1) (2)
|b|MIXED Gas / Standard light oil|bb
RLS 250/M MZ ●
MIXED Gas / Light oil Low NOX
RLS 310/M MX ● ● (2)
RLS 410/M MX ●(2)
RLS 510/M MX ●(2)
RLS 310/E MX ● ● (2)
RLS 410/E MX ●(2)
RLS 510/E MX ●(2)
GAS - PREMIX
RX 1800 S/E ●20163866
RX 2500 S/E ●20163866
RX 3000 S/E ● ● 20163866
(1) For altitudes over 1800 meters
(2) To replace on the burner head tted as standard
NOTE: burners must be tted with a gas ramp device.
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
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.
RS gas - RLS gas/Light oil burner
RX premix burner
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
A
A
TAU N
1750 2100 2600 3000
Burner head
L min. (mm) 350 350 350 500
Hole in door
Ø (mm) 520 520 520 520
0 Do not re-use old burners if their blast tube lengths are be-
low those specied in the table.

9
GENERAL INFORMATION
GENERAL INFORMATION
1.8 Technical specications
DESCRIPTION TAU N
1750 2100 2600 3000
Device type Condensing boiler for central heating B23 - B23P (*)
Fuel All GASES
Device category See Burner
Rated heat input (Q max) GCV (NCV) 1943,0 2331,0 2886,0 3330,0 kW max
(1750) (2100) (2600) (3000)
Rated heat input (Q min) GCV (NCV) 1611,5 1943,6 2332,1 2887,1 kW min
(1451) (1751) (2101) (2601)
Useful (rated) heat output 1718,5 2062,2 2553,2 2946,0 kW max
Minimum nominal useful output (80/60°C) ( Pn min) 1424,0 1721,2 2065,3 2556,8 kW min
Maximum useful output (40/30°C) 1881,2 2258,7 2796,5 3226,8 kW max
30% heat output with return at 30°C (P1) 570,7 684,8 847,9 978,3 kW max
Efciency at rated heat input and in High tempera-
ture mode n4 ( 80/60°C) GCV NCV
88,5 88,5 88,5 88,5 %
(98,2) (98,2) (98,2) (98,2)
Useful efciency at Pn min (80/60°C) HCV (LCV) 88,6 88,6 88,6 88,6 %
(98,3) (98,3) (98,3) (98,3)
Useful efciency at Pn Max (40/30°C) GCV (NCV) 96,9 96,9 96,9 96,9 %
(107,5) (107,5) (107,5) (107,5)
Efciency at 30% rated heat input and in Low tem-
perature mode n1 with return 30°C GCV (NCV)
97,9 97,9 97,9 97,9
%
(108,7) (108,7) (108,7) (108,7)
Losses from stack for sensible heat (Qmax) 1,5 %
Losses from casing with burner on 0,3 %
Constant pressure drop (P.max) < 0,2 %
Flue gas temperature < 45÷75 (**) °C
Mass ue gas ow rate (Qmax) (***) 0,75 0,93 1,14 1,32 kg/sec
Furnace pressure 8,4 9,6 11,5 11,6 mbar
Furnace volume 1593,0 1810,0 2270,0 2632,5 dm3
Tot. volume of ue gas side 2525,0 3040,0 3830,0 4440,0 dm3
Total surface area for heat exchange 77,7 93,2 115,7 136,0 m2
Volumetric thermal load (Q.max) 1098,6 1160,2 1145,4 1139,6 kW/m3
Specic heat load 22,5 22,5 22,5 22,1 kW/m2
Max. condensate production Full load 30/50 °C 173,0 203,0 256,0 301,0 l/h
Max. operating pressure 6bar
Maximum permitted temperature 100 °C
Maximum operating temperature 90 °C
Pressure drop ∆T 10°C 30 78 56 mbar
Pressure drop ∆T 20°C 12 31 21 mbar
Water capacity 3060 3330 4700 5560 liters
Turbulators n. 158 175 194 224 No.
(*) The B23P conguration may only be adopted with premix gas burners.
(**) Depends on return temperature (30-60°C)
(***) At Pn max and Tm = 80°C, Tr = 60°C e CO2 = 10,3%
9 The stack must guarantee the minimum draught specied by applicable technical standards, assuming zero pressure at the
connection to the ue.

10
SYSTEM MANAGER
SYSTEM MANAGER
2 SYSTEM MANAGER
2.1 Putting into service
Have R’s Technical Assistance Service start up your RTAU N
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