Riello RTQ 3S Series Owner's manual

INSTALLATION, OPERATION, MAINTENANCE
AND SYSTEM MANAGEMENT MANUAL
STEEL BOILERS
RTQ 3S
35-55-70

2
RTQ 3S rboilers conform to the Efficiency Directive 92/42/CEE (✫✫✫).
When used in conjunction with a CE marked jet burner, they also
satisfy the requirements of the Gas Appliances Directive 2009/142/EC (until 20 April 2018 ) and
Regulation (EU) 2016/426 (from 21 April 2018) and applicable sections of the Electromagnetic
Compatibility Directive 2004/108/CE and Low Voltage Directive 2006/95/CE.
CONFORMITY
RANGE
MODEL CODE
RTQ 35 3S 20025617
RTQ 55 3S 20025618
RTQ 70 3S 20025619

3
Dear Customer,
Thank you for choosing a RTQ 3S r, boiler. You have purchased a modern, high effi-
ciency, quality product that is designed to give dependable and safe service and to pro-
vide comfort in the home for many years to come. Arrange for your boiler to be serviced
regularly by an authorised rTechnical Assistance Centre. Their personnel are specially
trained to keep your boiler efficient and cheap to run. Technical Assistance Centres 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 trouble-free installation and efficient functioning of your RTQ 3S
r boiler.
Please accept our renewed thanks for your purchase.
Riello S.p.A.

4CONTENTS
GENERAL
General safety information page 5
Precautions “ 5
Product description “ 6
Control panels “ 7
Recommended burners “ 8
Product identification “ 9
Technical specifications “ 10
Accessories “ 10
SYSTEM MANAGER
Start up page 11
Temporary shutdown “ 12
Preparing for extended periods of disuse “ 13
Cleaning “ 13
Maintenance “ 14
Useful information “ 14
HEATING ENGINEER
Unpacking the product page 15
Overall dimensions and weights “ 16
Handling “ 16
Place of installation “ 17
Positioning the boiler “ 17
Installation in older systems and systems
requiring modernisation “ 18
Water connections “ 18
Anti-condensate pump “ 20
Combustion gas exhaust “ 20
Door hinges “ 21
Changing the direction of door opening “ 21
Earth connection “ 24
Fitting the casing panels “ 25
TECHNICAL ASSISTANCE SERVICE
Preparing for initial start-up page 26
Initial start-up “ 27
Checks during and after initial start-up “ 28
Maintenance “ 29
- Opening the door “ 29
- Adjusting the door “ 29
Cleaning the boiler “ 30
Troubleshooting “ 31
This manual, Code 20025364 Rev. 14 (04/18) is made up
of 32 pages.
The following symbols are used in this manual:
b CAUTION! = Indicates actions that require cau-
tion and adequate preparation
aSTOP! = Identifies actions that you MUST NOT do
CONTENTS

GENERAL 5
b The boiler is delivered in separate crates. Check
that it is complete, undamaged and as ordered as
soon as you receive it. Report any discrepancies or
damage to the dealer who sold it.
b The RTQ 3S r boiler must be installed by a
legally qualified heating engineer. On completion
of the installation, the installer must issue the owner
with a declaration of conformity confirming 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
conforms to all applicable laws and standards.
b The boiler must only be used for the purpose
specified by rand for which it is designed. The
manufacturer declines all responsibility, contractual
or other, for damage to property or injury to persons
or animals caused by improper installation, adjust-
ment, maintenance or use.
b If you notice any water leaking from the boiler, dis-
connect it immediately from the mains electricity
supply, shut off the water supply, and notify your
local rTechnical Assistance Centre or a quali-
fied heating engineer immediately.
b Periodically check that operating pressure in the
water circuit is over 1 bar but below the maximum
limit specified for the boiler. If this is not the case,
contact r’s Technical Assistance Service or a
professionally qualified heating engineer.
b If the boiler is not going to be used for an extended
period of time, contact r’s Technical Assistance
Service or a qualified heating engineer to have it
prepared for shut-down as follows:
- Switch the boiler OFF at the control panel and at the
mains power switch
- Close the fuel cock and heating circuit water cock
- Drain the central heating circuit if there is any risk of
freezing.
b Drain the central heating circuit if there is any risk of
freezing
b This instruction manual is an integral part of the boil-
er. It must be kept safe and must ALWAYS accom-
pany 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 replace-
ment immediately from your local rTechnical
Assistance Centre.
aDo not allow children or infirm persons to operate
this RTQ 3S r boiler unsupervised.
a Do not operate any electrical devices or equipment,
including switches or domestic appliances, etc., if you
can smell fuel or fumes. If you detect any suspicious
smells:
- Ventilate the room by opening all doors and win-
dows.
- Close the fuel shut-off cock.
- Report the fault immediately to the rTechnical
Assistance Service or a professionally qualified
heating engineer.
aDo not touch the boiler while barefoot or wet.
aNever clean or service the boiler without first discon-
necting it from the mains electricity supply by turning
the main power switch and the control panel switch
OFF.
aDo not tamper with or adjust the safety or control
devices without prior authorisation and instructions
from the boiler’s manufacturer.
aNever pull, disconnect, or twist the electrical cables
coming from the boiler even if it is disconnected from
the mains electricity supply.
aDo not obstruct or restrict the vents in the room
where the boiler is installed. Adequate ventilation is
essential for correct combustion.
aDo not expose the boiler to the elements. Do not
install the boiler outdoors. It is not designed to work
outdoors and is not fitted with the necessary auto-
matic anti-frost systems to do so.
aDo not switch the boiler off if outdoor temperature
drops below ZERO (risk of freezing).
aDo not store containers of flammable substances in
the room where the boiler is installed.
aDo not dispose of packaging material into the envi-
ronment, or leave it within the reach of children,
since it can become a potential hazard. Dispose of
packaging material in compliance with applicable
legislation.
The operation of any appliance that uses fuel, electrical power and water demands that a number of fundamental safety
precautions be respected.
GENERAL SAFETY INFORMATION
PRECAUTIONS

GENERAL
6
RTQ 3S rsteel boilers are high efficiency boilers
with horizontal, flame reversal combustion chambers
and concentrically arranged flue gas pipes. They are
designed for central heating and, when used in conjunc-
tion with a suitable storage cylinder, for domestic hot
water production too.
Because they operate at low pressure, they provide a
gradual heating action without thermal shock.
The most important technical features of these boilers are:
- The combustion chamber and heat exchange system
are specially designed and shaped to achieve the best
possible volume ratio.
- Only top quality materials are used to ensure a long
working life.
Stainless steel turbulators inside the flue gas pipes
establish an ideal pressure inside the combustion cham-
ber and an ideal flue gas temperature. Evenly distributed
thermal load optimises the efficiency of the boiler-burner
system.
The boiler body is thoroughly insulated with a layer of
high density glass wool.
The boiler’s front door and the flue gas box can be
opened completely to facilitate the inspection, mainte-
nance and cleaning of internal parts and to speed up
servicing in general.
The front door can open in either direction, even without
removing the burner.
PRODUCT DESCRIPTION
3
2
1
4 5
14
7
10
11
12
13
8
6
9
1 - Burner
2 - Flame inspection window
3 - Door
4 - Casing
5 - Flue gas pipes
6 - Instrument bulb/sensor sockets
7 - Central heating flow
8 - Turbulators
9 - Combustion chamber
10 - Flue gas exhaust
11 - Flue gas box
12 - Inspection window
13 - Condensate drain
14 - Central heating return

GENERAL 7
CONTROL PANELS
The r control panels that can be used with r RTQ 3S 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.
Respect the indications of the table rigorously to ensure trouble-free operation and maximum reliability of your boiler
over time.
CONTROL PANELS MINIMUM CH FLOW TEMPERATURE
MODEL TYPE T° > 50°C T° > 40°C
TECH CLIMA TOP Climate control •
TECH CLIMA COMFORT Climate control •
TECH CLIMA MIX Climate control •
TECH PRIME Electro-mechanical •
TECH PRIME ACS Electro-mechanical •
b When a TECH CLIMA TOP or CLIMA COMFORT control panel is installed, the boiler return (cold) line must be
equipped with a temperature sensor socket.
See the catalogue for the necessary accessory part numbers.
Single stage Two stage Modulating Cascaded Wood fuelled Solar DHW Direct CH circuit Mixed CH zone 1 Mixed CH zone 2
1 2
M
°C
1 2
M
°C
1 2
M
°C
1 2
M
°C
1 2
M
°C
1 2
M
°C
1 2
M
°C
1 2
M
°C
1 2
M
°C
1 2
M
°C
CLIMA TOP
STANDARD    
Control by control panel with assistance of
accessories listed below
     
ACCESSORIES
Immersion temperature sensor 1 1 1 1
Solar collector temperature sensor 1
Pipe temperature sensor 1 1
CLIMA COMFORT
STANDARD  
Control by control panel with assistance of
accessories listed below
     
ACCESSORIES
Immersion temperature sensor 1 1 1
Solar collector temperature sensor 1
Pipe temperature sensor 1 1
Two-stage burner control kit 1
1 mixed zone kit 1
CLIMA MIX
STANDARD 
Control by control panel with assistance of
accessories listed below

ACCESSORIES
Pipe temperature sensor 1 1
1 mixed zone kit 1
PRIME
STANDARD  
Control by control panel with assistance of
accessories listed below

ACCESSORIES
Two stage burner kit 1
PRIME ACS
STANDARD   
Control by control panel with assistance of
accessories listed below

ACCESSORIES
Two stage burner kit 1
Total shutdown kit 1 1

GENERAL
8
b See the instruction manual provided with the burner for further information on:
- burner installation
- electrical connections
- burner adjustments.
b 1 - Long heads and burner plates are required for the correct installation and coupling of the burners.
2 - If a two stage burner is installed, 1st stage heat input must not be less than 70% of total heat input. With liquid
fuel burners equipped with 2 nozzles, it is therefore important to choose the correct first stage nozzle.
3 - In Italy, the Decree of the President of the Council of Ministers of the 2nd October 1995 requires that heating
systems with heating power of less than 3 MW use fuel oil with a sulphur content of less than 0.3 % by weight.
A
Ø
L
IMPORTANT NOTES FOR BURNER
INSTALLATION
Before fixing 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 fixing bolts is less than
(S), i.e. the total depth of the seal, plates and washer.
Longer bolts can cause the door to warp, compro-
mising 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.
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
adequate for the requirements of the boiler
- Make sure that the length and diameter of the burner’s
blast tube are as specified in the following table.
RECOMMENDED BURNERS
DIMENSIONS (mm) RTQ 3S
35 55 70
L min. 115 115 170
Ø hole in door 110 110 140
L < S
S
L

GENERAL 9
b When you finish installing the burner in the boiler,
fill the gap between the burner’s blast tube and the
refractory material in the door with the ceramic insu-
lation (A) supplied with the boiler.
45°
45°
A
A
Ø
BURNER PLATE
RTQ 3S rboilers have burner plates with holes
arranged to accept the recommended burners. The fol-
lowing table shows the dimensions of the holes.
PRODUCT IDENTIFICATION
b If these plates or any other means of clearly identifying the product are defaced, removed or lost, proper installation
and servicing may be rendered difficult.
- Serial number plate
This is located on the boiler body and specifies
the serial number, model, and furnace power.
- Data plate
This lists the technical specifications and perfor-
mance 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.
The boilers are identified by two plates:
DIMENSIONS (mm) RTQ 3S
35 55 70
Ø 110 110 140
A 106 106 120
Threads M8 M8 M8
WEEK OF
MANUFACTURE
23270000581
b Blast tubes must not exceed the specified lengths
by more than 20%.
aDo not re-use old burners if their blast tube lengths
are below those specified in the table.

GENERAL
10
b The stack must guarantee the minimum draught specified by applicable technical standards, assuming zero pres-
sure at the connection to the flue gas exhaust.
b Values obtained with Rgas burners, calibrated with CO2= 9,7%, λ= 1,2 and with Rfuel oil burners calibrated
with CO2= 12,5%.
TECHNICAL SPECIFICATIONS
DESCRIPTION RTQ 3S
35 55 70
Fuel GAS / OIL
Rated heat input min 25 35 55 kW
max 34,8 55 69 kW
Rated useful heat output Pn min 23,6 33,3 51,8 kW
max 32,8 51,6 65,0 kW
Useful efficiency at minimum Pn 94,2 95,1 94,2 %
Useful efficiency at maximum Pn 94,2 93,8 94,2 %
Useful efficiency at 30% (47°C) 95,9 95,5 95,9 %
Constant pressure drop < 1,5 %
Flue gas temperature 98 94 92 °C
Flue gas mass flow rate 0,015 0,024 0,030 kg/sec
Furnace pressure 0,4 0,9 0,6 mbar
Furnace volume 37,8 45,2 80,2 dm3
Total volume of flue gas side 62,2 73,4 119,1 dm3
Total surface area for heat exchange 1,90 2,50 3,02 m2
Volumetric heat load 921 1187 872 kW/m3
Specific heat load 17,8 21,3 22,4 kW/m2
Maximum operating pressure 6 bar
Maximum admissible temperature 110 °C
Maximum operating temperature 95 °C
Min. admissible water return temp. 50 °C
Pressure drop ∆T 10°C 10,0 20,0 40,0 mbar
Pressure drop ∆T 20°C 5,0 3,0 10,0 mbar
Water capacity 71 87 103 litres
Turbulators 14 16 22 n°
ACCESSORY CODE
Hydraulic connection kit r7300 4030030
ACCESSORIES

11
SYSTEM MANAGER
START UP
Have r’s Technical Assistance Service start up your RTQ 3S boiler for the first time. Once this has been done, the
boiler can be left to function automatically.
Under certain circumstances, such as after long periods of disuse, 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 pres-
sure in the water circuit is over 1 bar but below the
maximum limit specified for the boiler
- If the system is equipped with a temperature controller
or timer thermostat, make sure that it is switched on
- Adjust the timer thermostat/s or temperature controller
to the desired temperature (~20°C)
- Turn the system’s main 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 man-
ual for your control panel.
20
40
60
80
100
0120
20
40
60
80
100
0120

SYSTEM MANAGER
12
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
maintain 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.
b If a “LOCKOUT SHUTDOWN” occurs, wait about 30
seconds before resetting the burner.
To reset the burner, press the red button light on the
burner and wait until the flame ignites.
Repeat this operation 2 -3 times at the most. If the prob-
lem persists after that, call r’s Technical Assistance
Service.
If you need to shut down the system for a short period,
proceed as follows.
-Turn the control panel power switch OFF and make
sure that the green power indicator goes out
- Turn the mains power switch OFF
b Do NOT perform this procedure if outdoor tempera-
ture falls below ZERO (risk of freezing).
Then proceed as follows:
-Adjust the boiler thermostat to its minimum setting
(60°C)
- Make sure that the temperature controller or timer /
room thermostat is set to “frost protection” mode.
TEMPORARY SHUTDOWN
20
40
60
80
100
0120
20
40
60
80
100
0120

13
SYSTEM MANAGER
PREPARING FOR EXTENDED PERIODS OF DISUSE
CLEANING
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 mains power switch OFF
- Close the fuel cock and heating circuit water cock
- Drain the central heating circuit if there is any risk of
freezing
b Contact rTechnical Assistance Service if you
encounter any problems in completing the above
procedure.
20
40
60
80
100
0120
b The combustion chamber and flue pipes must be
cleaned periodically by the Technical Assistance
Service or by a qualified heating engineer (see page
30).
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 clean-
ing product.
Carefully dry the boiler after cleaning.
aDo not use abrasive cleaning pads or powder deter-
gents.
aNever clean the boiler without first disconnecting it
from the mains electricity supply by turning the main
power switch and the control panel switch OFF.

SYSTEM MANAGER
14
Seller: .............................................................................................................................................
Mr. .......................................................................................................................................................
Address .......................................................................................................................................
Tel. ......................................................................................................................................................
Technical Assistance Service: ....................................................................
Mr. .......................................................................................................................................................
Address .......................................................................................................................................
Tel. ......................................................................................................................................................
Fuel oil supplier: ............................................................................................................
Mr. .......................................................................................................................................................
Address .......................................................................................................................................
Tel. ......................................................................................................................................................
Installer:.......................................................................................................................................
Mr. ......................................................................................................................................................
Address ......................................................................................................................................
Tel. .....................................................................................................................................................
r’s Technical Assistance Service is qualified 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 fines in the event of spot
checks.
Date Work done
Date Quantity supplied Date Quantity supplied Date Quantity supplied Date Quantity supplied
MAINTENANCE
USEFUL INFORMATION

HEATING ENGINEER 15
A
RTQ 3S rsteel boilers come in 3separate crates:
1) BOILER BODY CRATE to which is attached the
documentation envelope (A) containing:
- Instruction manual
- Data label (to be applied to the casing on comple-
tion of the installation)
- Certificate of Warranty and water test certificate
- Bar code labels
- Spare parts catalogue
b The instruction manual is an integral part of the
boiler. Once located, read it thoroughly and keep it
safe.
2) THE CASING PANELS complete with assembly
accessories.
3) THE FRONT COVER to fit on top of the front door.
IMPORTANT
For the boiler to function correctly, it must be connected
to a r TECH control panel and dedicated control
accessories.
UNPACKING THE PRODUCT

HEATING ENGINEER
16
A
A1
C
D1
160
B
B1 E
D
OVERALL DIMENSIONS AND WEIGHTS
HANDLING
RTQ 3S rsteel boilers are fitted with lifting attach-
ments. Take great care when moving them and only use
lifting equipment of adequate capacity.
Remove the fixing screws and remove the wooden pallet
before positioning the boiler.
b Wear suitable personal protective equipment and
use suitable safety devices.
DIMENSIONS RTQ 3S
35 55 70
A - Width 605 605 705 mm
A1 - Base width 560 560 660 mm
B - Depth 830 980 910 mm
B1 - Base depth 623 773 672 mm
C - Height 605 605 740 mm
D - Burner height 310 310 384 mm
D1 - Flue height 325 325 384 mm
E - Door depth 110 110 135 mm
Weight of boiler 119 140 177 Kg
Weight of casing 18 20 22 Kg

HEATING ENGINEER 17
PLACE OF INSTALLATION
POSITIONING THE BOILER
RTQ 3S r steel boilers must be installed in a dedi-
cated boiler room, with adequately sized vents, in compli-
ance with applicable laws and standards.
If at all possible, the boiler should be installed on a raised
base to prevent the burner fan sucking up dust.
rRTQ 3S boilers can be positioned:
On the floor or pedestal
The ideal solution for just heating installation.
b If you are installing the boiler without a pedestal, the
limited gap between the burner and the floor makes
it particularly important to keep the boiler room
clean.
On the heater
This is more practical with a combined installation (heat-
ing and hot water).
In this case, r 7300 boiler heater combinations are
used, as this heater has been specifically designed and
manufactur ed to support the weight of the boiler.
b When installing the boiler, allow sufficient space
around it to access all safety and control devices
and to permit easy maintenance.
b If the specific weight of the gas supply to the burner
is greater than the specific weight of air, install all
electrical parts at least 500 mm above floor level.
aDo not install the boiler outdoors. It is not designed
to work outdoors and is not fitted with the necessary
automatic anti-frost systems to do so.

HEATING ENGINEER
18
E
H
DGF
25
C
B
A
RTQ 3S rboilers 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 fittings are as specified in the fol-
lowing table.
b Allow for the dimensions of the control panel that
needs to be installed on top of the boiler.
WATER CONNECTIONS
INSTALLATION IN OLDER SYSTEMS AND SYSTEMS REQUIRING MODERNISATION
When installing these boilers in old systems or systems
requiring modernisation, always perform the following
checks:
- Make sure that the stack is able to withstand the tem-
perature of the combustion gases and that it has been
designed and made in compliance with applicable
standards. The stack must also be as straight as pos-
sible, sealed, insulated and not blocked or choked.
- Make sure that the electrical system has been installed
by a qualified electrician in compliance with applicable
standards.
- Make sure that the oil feed line and any oil storage tank
are made and installed in compliance with applicable
standards.
- Make sure that the expansion vessels are big enough to
contain the volume generated by thermal expansion.
- Make sure that flow rate, head and direction of flow of
the pumps are suitable and correct.
- Make sure that the circuit has been flushed out to
remove all sludge and lime scale, and has been vented
and seal tested.
- Make sure that a suitable water treatment system is
installed if the quality of the supply/recirculation water
so demands. (See page 20).
DIMENSIONS RTQ 3S
35 55 70
A - Return-base distance 85 85 110 mm
B -
Delivery/return centre to centre distance 455 455 552 mm
C - Flue gas discharge projection 50 50 60 mm
D - Del./ret. centre to centre distance condensation safety/
discharge 75 75 85 mm
E - System delivery 1" 1/4 1" 1/4 1" 1/2 Ø
F - System return/boiler discharge 1" 1/4 1" 1/4 1" 1/2 Ø
G - Flue pipe condensation discharge 1/2" 1/2" 1/2" Ø
H - Instrument bulb / sensor socket G 1/2" - Ø 16 Ø

HEATING ENGINEER 19
1
8
315 10 3
FILLING
ENTRANCE
14
EMPTY
HOT WATER
OUTLETS 3135312
EMPTY
16
9
3
2
3
SYSTEM
DELIVERY
4
5
3
3
2
3
SYSTEM
RETURN
9
11
76
b The choice of system components and the method
of their installation are left up to the heating engineer
installing the system. Installers must use their exper-
tise to ensure proper installation and functioning in
compliance with all applicable legislation.
b Circuits filled with anti-freeze must be fitted with
water disconnectors.
b If needed, water supplies and recovery circuits must
be conditioned by suitable treatment systems. See
the table alongside for reference values.
REFERENCE VALUES
PH 6-8
Electrical conductivity below 200 mV/cm (25°C)
Chlorine ions below 50 ppm
Sulphuric acid ions below 50 ppm
Total iron below 0,3 ppm
Alkalinity M below 50 ppm
Total hardness 35° F
Sulphur ions none
Ammonia ions none
Silicon ions below 30 ppm
Below are given the two main hydraulic diagrams:
FILLING
ENTRANCE
3 3
11
10
8
7
3
2
3
SYSTEM
RETURN
3
2
3
SYSTEM
DELIVERY
4
5
3
1
6
EMPTY
9
Heating and hot water installation
Just heating installation
1 - Boiler
2 - System headers
3 - Sectioning valves
4 - System circulators
5 - Check valves
6 - Automatic pressure relief valve
7 - Boiler safety valve
8 - Boiler discharge valve
9 - Expansion tank
10 - Pressure reducer
11 - Manual fast filling valve
1 - Boiler
2 - System headers
3 - Sectioning valves
4 - System circulators
5 - Check valves
6 - Automatic pressure relief valve
7 - Boiler safety valve
8 - Boiler discharge valve
9 - Expansion tank
10 - Pressure reducer
11 - Manual fast filling valve
12 - r7300 heater
13 - Hot water recycle pump
14 - Heater safety valve
15 - Water softener filter
16 - Heater discharge valve

HEATING ENGINEER
20
D
3÷5 D
b A sensor socket must be positioned at a distance of 3 to 5 times the diameter of the water return pipe, upstream
from the water fitting, to measure effective water return temperature and control the anti-condensate pump or the
temperature controller stabilisation function.
b Any temperature controllers installed remotely from the control panel must be compatible with the system’s electrical
connections and functioning logic.
An anti-condensate pump operates during periods of
no heat request to avoid damage until the boiler returns
to a stable operating temperature. While the system is
operating, this pump must guarantee a flow rate between
20 and 30% maximum flow to ensure a water return
temperature no lower than 55 °C. Pump shutdown must
also be delayed for at least 3 minutes at the beginning of
extended periods of boiler shutdown (overnight or week-
end shutdown etc.).
ANTI-CONDENSATE PUMP
COMBUSTION GAS EXHAUST
The flue gas exhaust and its connection to the stack
must be made in compliance with applicable laws and
standards, using heat resistant, condensate resistant and
stress resistant rigid pipe and sealed joints.
Ø
H1
H2
DIMENSIONS (mm) RTQ 3S
35 55 70
Ø 139 139 179
H1 325 325 384
H2 (with heater) 950 950 1010