Riello Condexa PRO NA 75 P Setup guide

cod. 20144490 rev. 0 09/2018
9
WARNING: If the information in this manual is not
followed exactly, a fire or explosion may result causing
property damage, personal injury or loss of life.
Do not store or use gasoline or other flammable
vapors and liquids or other combustible materials in
the vicinity of this or any other appliance. To do so
may result in an explosion or fire.
What to do if you smell gas:
- Do not try to light any appliance;
- Do not touch any electrical switch; do not use any
phone in your building;
- Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions;
- If you cannot reach your gas supplier, call the fire
department.
Installation and service must be performed by a
qualified installer, service agency or the gas supplier.
This manual should be maintained in legible
condition and kept adjacent to the boiler or in a safe
place for future reference.
Condexa PRO NA 75 P
Condexa PRO North America
INSTALLATION, OPERATION AND SERVICE MANUAL

2
This manual, Code 20144490 - Rev. 0 (09/2018)
comprises 112 pages.
RANGE
MODEL CODE
Condexa PRO NA 75 P 20142594
Condexa PRO NA 117 P 20142595
CONFORMITY
The Condexa PRO NA boiler range complies with:
ENGLISH
Dear customer,
Thank you for choosing a Rheating product, a quality product
that is designed to give dependable, efcient and safe service;
which will provide comfort in the home for many years to come.
This manual provides information that is essential to the instal-
lation of the appliance. Used in conjunction with a qualied in-
staller, service technician or the gas supplier's knowledge and ex-
pertise will allow for a quick, simple and correct appliance install.
Please accept our thanks, and congratulations on your choice of
product.
Riello S.p.A.
INTENDED USE
This boiler must only be used for the purpose specied by the
manufacturer and 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, adjustment, maintenance or use.
Installation of the boiler must comply with all applicable codes
and regulations imposed by the national, Federal or local author-
ities and bodies. If no specic requirements are dened, in the
USA, the latest edition of the National Fuel Gas Code ANSI Z223.1/
NFPA 54 must be complied with. In Canada, installation must be in
accordance with the requirements of CAN/CSA B149.1, Natural Gas
and Propane Installation Code.
Where required by local regulations, the system must comply with
the American Society of Mechanical Engineers Safety Code for Con-
trols and Safety Devices for Automatically Fired Boilers (ASME CSD-
1).
This manual, Code
- Rev.
comprises
pages.

3
CONTENTS
1 GENERAL INFORMATION ............................4
1.1 Key to symbols ................................4
1.2 General Safety Information ......................4
1.3 Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3.1 General warnings..............................5
1.4 Description of the appliance .....................7
1.5 Safety devices ................................7
1.6 Identication .................................8
1.7 System layout.................................9
1.8 Technical specications .........................11
1.9 Pumps ..................................... 12
1.10 Water circuit................................. 12
1.11 Positioning of the temperature sensors ............ 12
1.12 Control panel ................................ 13
1.13 Regulations and Guidelines ..................... 14
1.13.1 Compliance with standards and regulations ........ 14
1.13.2 Operating limits of the boiler .................... 14
1.13.3 Additional regulations for installations in the
Commonwealth of Massachusetts ................ 14
2 INSTALLATION .....................................15
2.1 Unpacking the product ........................ 15
2.1.1 Positioning of labels........................... 15
2.2 Overall dimensions and weights ................. 15
2.3 Installation premises .......................... 16
2.3.1 Installation clearances ......................... 16
2.4 Installation in older systems and systems requiring
modications ............................... 16
2.5 Moving and removing the packaging .............. 16
2.6 Boiler assembly ...............................17
2.7 Water connections ............................ 18
2.8 ASME pressure relief valve....................... 19
2.9 Low Water Cutoff ............................. 19
2.10 Typical water system schematics .................20
2.11 Gas connections .............................23
2.12 Combustion gas exhaust .......................23
2.13 Venting and air piping system ...................25
2.13.1 General venting and combustion air piping system ...25
2.13.2 Connecting ue gas systems .................... 27
2.13.3 Installation of the exhaust and air intake system.....28
2.13.4 Vent and combustion air pipe length [For single boiler
installations] ................................30
2.13.5 Approved examples of horizontal and vertical venting
installation ................................. 31
2.13.6 Multiple boilers ..............................34
2.13.7 De-rating for altitude installation.................35
2.13.8 Multiple boiler cascade system...................36
2.13.9
Vent and combustion air pipe length for cascade system .37
2.13.10Preparation for the condensate drain..............38
2.13.11 Water Chemistry Guidelines .....................39
2.14 System lling and emptying.....................39
2.14.1 Filling......................................39
2.14.2 Emptying ...................................40
2.15 Wiring diagram .............................. 41
2.16 Ladder diagram ..............................43
2.17 Electrical connections .........................44
2.18 Electronic control ............................. 47
2.18.1 Menu structure ..............................48
2.18.2 Parameters' list ..............................54
3 CONFIGURATION OF THE MAIN BLOCK DIAGRAMS ..61
3.1 Conguration of the primary system .............. 61
3.2 Conguration of the secondary system.............62
3.3 Block diagram 1 ..............................63
3.3.1 Electrical power connections Block diagram 1........63
3.3.2 Sensor connections Block diagram 1...............64
3.3.3 Bus connections Block diagram 1 .................64
3.4 System parameters Block diagram 1 ...............64
3.5 Block diagram 2 ..............................65
3.5.1 Electrical power connections Block diagram 2 .......65
3.5.2 Sensor connections Block diagram 2 ..............66
3.5.3 Bus connections Block diagram 2 .................66
3.6 System parameters Block diagram 2 ...............66
4 COMMISSIONING AND MAINTENANCE...............67
4.1 Lighting instructions...........................67
4.2 Introduction.................................67
4.3 Filling the Condensate System ...................67
4.4 Filling the Boiler Heating System .................67
4.5 Warnings Concerning the Gas Supply ..............67
4.6 Gas Type Conversion ...........................68
4.7 Initial startup ................................68
4.7.1 Switching the appliance on and off . . . . . . . . . . . . . . . 68
4.7.2 Date and time setting .........................68
4.7.3 Password access..............................69
4.7.4 Setting the heating parameters and outdoor reset.... 70
4.7.5 Setting the domestic hot water parameters ......... 73
4.7.6 Scheduled program ........................... 74
4.7.7 Boiler information ............................76
4.8 Checks during and after initial start-up ............ 77
4.9 Error List....................................78
4.9.1 Permanent Errors.............................79
4.9.2 Temporary Errors .............................79
4.9.3 Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.10 Converting gas type ...........................80
4.10.1 Converting gas type LPG . . . . . . . . . . . . . . . . . . . . . . . . 80
4.10.2 Converting gas type MTN........................82
4.11 Combustion Analysis ..........................85
4.12 Temporary or short-term shut-down..............86
4.13 Preparing for extended periods of shut-down .......87
4.14 Maintenance ................................87
4.14.1 "Service reminder" function.....................88
4.15 Cleaning and removing internal components........89
4.16 Troubleshooting ..............................92
5 SYSTEM MANAGEMENT ............................93
5.1 Communication between the boilers ..............93
5.1.1 Setting the dip-switch .........................93
6 SETTING PARAMETERS OF THE CASCADE SYSTEMS94
6.1 Parameters specic to cascade systems . . . . . . . . . . . . 94
6.1.1 Setting the main parameters ....................96
6.1.2 Par.73 – Managing, Stand-alone, Dependent mode. ..96
6.1.3 Par.147 – No. of boilers .........................96
6.1.4 Par.7 – heating setpoint hysteresis . . . . . . . . . . . . . . . . 96
6.1.5 General operation ............................96
6.2 Operation with the primary sensor................96
6.3 Operation with the secondary sensor..............96
6.4 Parameter 148: operating mode of the cascade ......97
6.4.1 Par 148 = 0 ..................................97
6.4.2 Par 148 = 1 ..................................97
6.4.3 Par 148 = 2 ..................................98
7 SYSTEM MANAGER ................................99
7.1 Commissioning ..............................99
7.2 Temporary or short-term shut-down............. 100
7.3 Preparing for extended periods of shut-down ...... 100
7.4 Cleaning................................... 100
7.5 Maintenance ............................... 100
7.6 Useful information ............................101
8 MODBUS CONNECTION............................102
9 COMMISSIONING LOG FOR THE APPLIANCE........106
10 RECYCLING AND DISPOSAL .......................108

4
GENERAL INFORMATION
1 GENERAL INFORMATION
1.1 Key to symbols
Pay attention to these terms:
9 DANGER = indicates the presence of immediate hazards
which will cause severe personal injury, death or substan-
tial property damage if ignored.
9 WARNING = indicates the presence of hazards or unsafe
practices which could cause severe personal injury, death
or substantial property damage if ignored.
9 CAUTION = indicates the presence of hazards or unsafe
practices which could cause minor personal injury or prod-
uct or property damage if ignored.
9 NOTE = indicates special instructions on installation, oper-
ation, or maintenance which are important but not related
to personal injury hazards.
0 STOP! = Identies actions that you MUST NOT do.
1.2 General Safety Information
9 Check that the product is complete, undamaged and as or-
dered as soon as you receive it. Report any discrepancies or
damage to the Rdealer who sold it.
9 The boiler must be installed by a qualied installer, service
agency or gas supplier.
UPON COMPLETION OF THE INSTALLATION THE INSTALLER MUST
INSTRUCT THE OWNER AND OPERATOR ON THE FUNCTIONALITY
AND THE PROPER OPERATION OF THE BOILER AND THE HEATING
SYSTEM.
THIS MANUAL SHOULD BE HANDED TO THE OWNER AND
OPERATOR OF THE APPLIANCE.
THE INSTALLER MUST REVIEW ALL SAFETY INSTRUCTIONS WITH THE
OWNER AND OPERATOR.
The installation instructions included in this Manual are
intended solely for use by a qualied installer, service
agency or gas supplier. If the information in this manual is
not followed exactly, a re or explosion may result causing
property damage, personal injury, or death.
−Have installation and service performed by a qualied in-
staller, service agency or the gas supplier.
−Rrecommends signing a service and maintenance con-
tract with a trained and qualied installer or service agency
that covers annual servicing and condition-based mainte-
nance. Proper maintenance is a fundamental requirement
for safe and efcient operation and long service life.
−The boiler must be serviced annually including the main
burner, ignition system, the entire venting system, and
the combustion air supply. All parts that show any signs of
damage or corrosion must be replaced.
9 WARNING: when servicing the boiler and venting components
ensure the boiler components and venting components are
installed properly per the Installation, Operation & Service In-
structions for the boiler as well as the vent manufacturer's
installation instructions and the local code having jurisdiction
are followed. Failure to comply may result in substantial prop-
erty damage, severe personal injury, or death.
−The owner and operator is responsible for the operational
safety and regulatory compliance of the heating system.
−Improper installation, adjustment, alteration, service, or
maintenance can cause property damage, personal injury,
or death. Refer to this manual and consult a qualied in-
staller or service agency, or the gas supplier before instal-
lation, service or maintenance.
−The boiler must be installed such that the gas ignition
system components are protected from water (dripping,
spraying, rain etc.) during boiler operation and circulator
replacement, condensate trap, control replacement, etc.
−The boiler must not be installed on carpeting.
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 property or
injury to persons or animals caused by improper installation,
adjustment, maintenance or use.
9 If you notice any water leaks, disconnect the boiler from the
main electrical supply and shut off the water supply.
9 Periodically check that pressure in the central heating circuit,
when cold, is approximately 20 psi (1.4 bar) and below the
maximum limit specied for the boiler.
9 If the boiler is not going to be used for an extended period of
time, perform the operations described later in this manual.
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 RTechnical As-
sistance Center.
9 The equipment, before being connected to the hydraulic sys-
tem and to the gas supply and being electrically powered can
be exposed to temperatures ranging between 39°F (4°C) and
104°F (40°C). Once it is able to activate the antifreeze func-
tions, it can be exposed to temperatures within -4°F (-20°C)
and 104°F (40°C).
9 Regularly check that the condensate drain is free from ob-
struction.
9 We recommend cleaning inside the heat exchanger once a
year, extracting the fan and burner and removing any instal-
lation debris using a vacuum. This operation should be done
by a qualied installer, service agency or gas supplier only.

5
GENERAL INFORMATION
1.3 Warnings
−Gas red hot water boiler for either direct vent installation.
Design according to: ANSI Z21.13-2017 CSA 4.9-2017 – Gas-
Fired low pressure hot water boilers. Direct vent boiler, Cat-
egory IV.
−SCAQMD Rule 1146.2
1.3.1 General warnings
9 DANGER: Make sure the gas on which the boiler will operate is
the same type as that specied on the boiler rating plate and
on the colored sticker near the boiler gas connection.
9 WARNING: Should overheating occur or the gas supply valve
fail sto shut off, turn off the manual gas control valve to the
appliance.
9 WARNING: Do not use this boiler if any part has been under
water. Immediately call a qualied service technician to in-
spect the appliance and to replace any part of the control sys-
tem and any gas control which has been under water.
9 WARNING: Automatic lling systems are not recommended
with this product as they will continually add fresh water to
the system if there is a leak resulting in the addition of new
contaminants that could reduce the lifespan of the boiler.
9 WARNING: To minimize the possibility of improper operation,
serious personal injury, re, or damage to the boiler:
−Always keep the area around the boiler free of combusti-
ble materials, gasoline, and other ammable liquids and
vapors.
−The boiler should never be covered or have any blockage to
the ow of fresh air to the boiler.
9 WARNING: Risk of electrical shock. More than one disconnect
switch may be required to de-energize the equipment before
servicing.
9 WARNING: Failure to comply with the above could result in se-
vere personal injury, death or substantial property damage.
Failure to adhere to the guidelines on this page can result in
severe personal injury, death or substantial property damage.
9 WARNING: Installation and service must be performed by a gas
supplier or a licensed qualied installer/service Technician.
9 CAUTION: This boiler requires forced water circulation when
the burner is operating. See minimum and maximum ow
rates. Severe damage will occur if the boiler is operated with-
out proper water ow circulation.
9 NOTE: When the boiler has been lled for the rst time or the
system has been drained and relled, it will be necessary to
release any air that may have become trapped within the ap-
pliance heat exchanger. Loosen the bleed screw until water
is released and then close. IMPORTANT, THERE ARE NO OTHER
MANUAL AIR RELEASE VALVES LOCATED ON THE APPLIANCE.
The following instructions must be observed
−The boiler must only be used for its designated purpose,
observing the Installation Instructions.
−Only use the boiler in combinations and with the accesso-
ries and spare parts listed.
−Other combinations, accessories and consumables must
only be used if they are specically designed for the in-
tended application and do not affect the system perfor-
mance and the safety requirements.
−Maintenance and repairs must only be carried out by au-
thorized professionals.
−You must report the installation of a condensing gas boiler
to the relevant gas and plumbing inspection authority and
have it approved.
−You are only allowed to operate the condensing gas boil-
er with the combustion air/ue gas system that has been
specically designed and approved for this type of boiler.
You must also observe:
−The local building regulations stipulating the installation
rules.
−The local building regulations concerning the air intake and
outlet systems and the chimney connection.
−The regulations for the power supply connection.
−The technical rules laid down by the gas utility company
concerning the connection of the gas connection to the lo-
cal gas main.
−The instructions and standards concerning the safety
equipment for the water/space heating system.
−The Installation instructions for building heating systems.
−The boiler must be located in an area where leakage of the
heat exchanger or connections will not result in damage
to the area adjacent to the boiler or to lower oors of the
structure. When such locations cannot be avoided, it is rec-
ommended that a suitable drain pan, adequately drained,
be installed under the boiler. The pan must not restrict
combustion air ow.
−The boiler must be installed such that the gas ignition
system components are protected from water (dripping,
spraying, rain etc.) during boiler operation and circulator
replacement, condensate trap, control replacement, etc.).
−The boiler must not be installed on carpeting.
−Do not restrict or seal any air intake or outlet openings.
−If you nd any defects, you must inform the owner of the
system of the defect and the associated hazard in writing.
9 DANGER: Flammable gas explodes. Beware if you smell gas:
there may be an explosion hazard!
9 WARNING: RISK OF CARBON MONOXIDE POISONING OR FIRE DUE TO
JOINT SEPARATION OR PIPE BREAKAGE. Ensure all of the venting
system is properly supported and secured per these instruc-
tions, venting manufacturer’s instructions and with the Na-
tional Fuel Gas Code, ANSIZ223.1/NFPA 54, CAN/CSA B149.1, and/
or applicable provisions of local building codes. Failure to do
so may result in substantial property damage, severe personal
injury or death.

6
GENERAL INFORMATION
Observe these instructions as general warnings:
−Rrecommends that an inhibitor - suitable for use with
stainless steel heat exchangers - is used to protect the
boiler and system from the effects of corrosion and/or elec-
trolytic action. The inhibitor must be administered in strict
accordance with the manufacturers instructions.
−When the boiler has been lled for the rst time or the
system has been drained and relled, it will be necessary
to purge any air that may have become trapped within the
appliance heat exchanger.
NOTE: Propylene glycol in the system must not exceed 40%.
Boiler water
−If you have an old system with cast iron radiators, thor-
oughly ush the system (without the boiler connected) to
remove sediment. The high-efciency heat exchanger can
be damaged by build-up or corrosion due to sediment
−Do not use petroleum-based cleaning or sealing com-
pounds in the boiler system. Gaskets and seals in the sys-
tem may be damaged. This can result in substantial prop-
erty damage.
−Do not use “homemade cures” or “boiler patent medi-
cines.” Substantial property damage, damage to boiler,
and/ or serious personal injury may result.
−Continual fresh make-up water will reduce boiler life. Min-
eral build up in heat exchanger reduces heat transfer, over-
heats the stainless steel heat exchanger, and causes fail-
ure. Addition of oxygen carried in by make-up water can
cause internal corrosion in system components. Leaks in
the boiler or piping must be repaired at once to prevent
make-up water.
−We recommend the use of water treatment additives to
prolong the life of the boiler and prevent against corrosion
and contaminant build ups in the heating system.
−Ensure piping in the heating system has an oxygen barrier.
Observe these instructions for space heating water:
−Thoroughly ush the system prior to lling. Only use un-
treated potable water to ll and top off the system.
−Do not use water softeners in the system.
−When using oxygen-permeable pipes, e.g. for oor heat-
ing systems, you must separate the system using heat ex-
changers. Unsuitable heating system water promotes the
formation of sludge and corrosion. This may damage the
heat exchanger or affect its operation.
Tools, materials and additional equipment
For the installation and maintenance of the boiler you will need
the standard tools for space heating, gas and water connection.
Disposal:
−Dispose of the boiler packaging in an environmentally
sound manner.
−Dispose of components of the heating system (e. g. boiler
or control device), that must be replaced, by taking them in
to an authorized recycling facility.
9 WARNING: If the information in these instructions is not fol-
lowed exactly, a re or explosion may result causing property
damage, personal injury or death.
9 WARNING: Do not store or use gasoline or other ammable
vapors and liquids in the vicinity of this or any other boiler.
0 WARNING: Do not obstruct or restrict the vents in the room
where the boiler is installed. Adequate ventilation is essential
for correct combustion. Failure to comply may result in sub-
stantial property damage, severe personal injury or death.
0 WARNING: Do not expose the appliance to weather elements.
It has been designed for indoor use only.
0 CAUTION: Do not switch off the appliance if the outdoor tem-
perature may drop below 32°F (0°C) (freezing hazard).
0 CAUTION: Do not activate the boiler without adequate water in
the heating system.
0 Individuals without specic qualications and skills shall not
remove the boiler's casing.
0 Individuals without specic qualications and skills shall not
remove the boiler's casing.
9 NOTE:
−Do not install a thermostatic ue gas damper downstream
of the draft hood.
−Do not tamper with, remove, or attempt to repair a blocked
vent switch.
−When replacing the blocked vent switch, install the new
part in the original location.
−A blocked vent switch tripping more than once indicates a
problem with the venting system or chimney which must
be repaired immediately.
−Ensure none of the vent pipes and chimneys are damaged
or blocked.
−Connect only one appliance to each venting system or
chimney, unless using an approved cascade vent system
listed in the section "Installation of the exhaust and air in-
take system".
−The venting system must not feed into or route through an-
other exhaust ue.
−The venting system must be inspected annually. All parts
that show any signs of damage or corrosion must be re-
placed.
−Never close off or reduce the size of the combustion air
openings.
−The boiler must not be operated until any obstructions
have been removed.
9 NOTE:
−Work on gas components may only be carried out by a
qualied installer, service agency or gas supplier.
−Appliance installation, the connection of gas and vent pip-
ing, initial commissioning, electrical connections and ser-
vice and maintenance must only be carried out qualied
installer, service agency or gas supplier.

7
GENERAL INFORMATION
1.4 Description of the appliance
The Condexa PRO NA it is a condensing, pre-mixed thermal mod-
ule consisting in a modulating thermal element.
It's available in two models of power: 75 kW (255.900 BTU/hr) and
117 kW (399.000 BTU/hr).
Optimal combustion management supports high thermal ef-
ciencies (Over 95%) and low polluting emissions.
The boiler is designed for sealed chamber operation.
The appliance in standard conguration is for indoor installation
to guarantee an IPX4D protection level.
9 The Condexa PRO NA boilers can be cascaded to reach a max-
imum power of 2.388.500 btu/hr. (700 KW).
The appliance's key technical features are
−helicoidal heat exchanger with a double coil smooth stain-
less steel pipe, to guarantee good corrosion resistance and
the option of operating with high ∆ts (up to 104°F [40°C]),
reducing system set-up times;
−maximum exhaust ue exit temperature 212°F [100°C];
−microprocessor management and control with self-diag-
nostics, shown by means of a display, and logging of main
errors;
−Anti-Frost function;
−pre-settings for room/heat demand thermostat for low
and high temperature ranges;
−option to manage a CH circuit and a DHW circuit with stor-
age tank;
−high-efciency and high residual discharge head circula-
tor;
−climate control function (available only when using the
outdoor temperature sensor accessory).
1.5 Safety devices
All appliance functions are electronically controlled by a dual pro-
cessor technology board.
Any malfunction results in the appliance being shut down and the
automatic closure of the gas valve.
The following is installed on the CH water circuit:
−Safety high-limit thermostat.
−Flow sensor capable of monitoring the main heating cir-
cuit's ow on an ongoing basis and of stopping the appli-
ance in the event of insufcient ow.
−Temperature sensors on supply and return lines that mea-
sure the temperature difference (∆t) between input and
output uid and allow the boiler to re when a demand
is made.
−Minimum pressure switch.
The following is installed on the combustion circuit:
−Gas solenoid with pneumatic gas ow compensation de-
pending on the suction line's air ow rate.
−Ignition/detection electrode.
−Flue gas temperature sensor.
9 WARNING: The triggering of safety devices indicates the mal-
function of a potentially hazardous situation. Therefore, con-
tact a service agency immediately. After a brief pause, it is
possible to try and restart the appliance (see section "Initial
startup").
9 WARNING: Safety devices must be a qualied installer, service
agency or gas supplier, using only original parts. Refer to the
spare parts catalogue supplied with the appliance. After mak-
ing the repair, check that the appliance is working properly.
0 WARNING: The appliance must not be put in service, even
temporarily, when tampered safety devices are not in opera-
tion or have been tampered with.
9 A low water cutoff may be required by state local code or some
insurance companies. Check code requirements before instal-
lation of the Condexa PRO NA boiler. If required:
−Use a low water cutoff designed for hydronic installations;
−Follow low water cutoff manufacturer’s instructions.
9 A hot water boiler installed above the radiation level or as re-
quired by the Authority having jurisdiction, must be provided
with a low water cutoff device either as part of the boiler or at
the time of boiler installation.

8
GENERAL INFORMATION
1.6 Identication
The products are identied by:
2
Gross output
Net IBR rating
Certified by RIEL
_____________________
LO S.p.A. (ITALY)
r
kW
Mbtu/hr
Mbtu/h
Mo
____
del
bar kPa psi
°F°C
m
kg/h lb/hr
Mbtu/hr
kW
gph=xaMhpg
kW /
kW
MAWP Water
Maximum water temp.
Heating surface
Minimum relief valve capacity
Electrical rating (burner)
SERIAL NUMBER
Less than 12 Amperes
Min. & Max. input gas:
2” (50mm)
::roferusserPtelnI
Design Manifold Pressure for: NG ___ "
wc to ___ "wc or LP ___"wc to ___ "wc
SQ FT
NG ___ " wc to ___ "wc or LP ___"wc to ___ "wc
Min =
Min. & Max. input oil: Min =
Max =
/Mbtu/h
r
Year built:
________ _________
Approved for use with Natural Gas (NG), Liquid Petroleum Gas (LPG), and/or
fuel oil not heavier than # 2 per ASTM D396.
Consult the Installation Manual for approved boiler and burner combinations.
MINIMUM REQUIRED CLEARANCES FOR INSTALLATION
BETWEEN COMBUSTIBLE CONSTRUCTIONS.
ONLY THESE INSTRUCTIONS MUST BE FOLLOWED EXACTLY.
LEFT, RIGHT,
FRONT SIDE
2” (50mm)
BOTTOM
0” (0mm)
REAR
16” (406mm)
TOP
Data plate
This lists the technical specications and performance of the
product. This is supplied inside the document bag and MUST BE
APPLIED to the boiler by the installer on completion of instal-
lation. If you damage or lose this label, order a replacement
immediately from your local Rboiler representative.
9 NOTE: If these plates or any other means clearly identifying the
product are defaced, removed or lost, proper installation and
servicing may be rendered difcult.

9
GENERAL INFORMATION
1.7 System layout
Condexa PRO NA 75 P
4
3
24
23
22
17
5
6
10
16
2
1
4
5
6
7
8
10
9
26
25
24
23
22
21
20
19
16
15
11
12 13 14
3
18
17
1 Flue gas exhaust connection
2 Exhaust ue temperature sensor
3 Gas valve
4 Fan
5 Combustion chamber
6 PCB (printed control board)
7 Flue check valve
8 Drain cock
9 Minimum Pressure Switch (set to 7 psi/0.5 bar)
10 Pump
11 Power switch
12 Central heating return
13 Gas supply
14 Central heating supply
15 Condensate drain connection
16 Flow-meter
17 Intake pressure for ue gas pressure switch
18 Return temperature sensor
19 Flue gas pressure switch
20 Control panel
21 Ignition/detection electrode
22 Safety Water High-limit Thermostat with manual
reset by PCB
23 Supply temperature sensor
24 Automatic air vent
25 Spark generator
26 Casing

10
GENERAL INFORMATION
Condexa PRO NA 117 P
26
25
20
10
24
23
22
2
1
3
4
5
6
7
8
14
131211
21
19
18
17
16
15
9
1
3
4
5
15
24
18
23
1 Flue gas exhaust connection
2 Exhaust ue temperature sensor
3 Fan
4 Combustion chamber
5 PCB (printed control board)
6 Flue check valve
7 Drain cock
8 Minimum Pressure Switch (set to 7 psi/0.5 bar)
9 Pump
10 Power switch
11 Central heating return
12 Gas supply
13 Central heating supply
14 Condensate drain connection
15 Flow-meter
16 Gas valve
17 Intake pressure for ue gas pressure switch
18 Return temperature sensor
19 Flue gas pressure switch
20 Control panel
21 Ignition/detection electrode
22 Safety Water High-limit Thermostat with manual
reset by PCB
23 Supply temperature sensor
24 Automatic air vent
25 Spark generator
26 Casing

11
GENERAL INFORMATION
1.8 Technical specications
Description Unit Condexa PRO NA 75 P Condexa PRO NA 117 P
Boiler category ASME Section IV ASME Section IV
Type of Gas Natural Gas, Propane*
Max input rate BTU/hr 255.900 399.204
(kW) (75) (117)
Min input rate BTU/hr 25.590 39.920
(kW) (7.5) (11.7)
Turndown Rate 10:1
Gas Connections (NPT) Ø Inch 1" 1/4
Max. NG Pressure
Inch
W.C. 10.5 10.5
(mbar) (26) (26)
Min. NG Pressure
Inch
W.C. 3.5 3.5
(mbar) (8.7) (8.7)
Max. LPG Pressure
Inch
W.C. 13 13
(mbar) (32) (32)
Min. LPG Pressure
Inch
W.C. 8.0 8.0
(mbar) (20) (20)
Water Connections (NPT) Ø Inch 1" 1/2
Max. Allowable Working Pressure (MAWP) PSI 80
(bar) (5.5)
Water Volume Gallon 44.5
(liter) (15.2) (17.0)
Water ow at max power
(∆T 36°F / 20°C)
GPM 13.2 19.8
(m3/h) (3) (4.5)
Water ow at max power
(∆T 45°F / 25°C)
GPM 10.1 15.9
(m3/h) (2.3) (3.6)
Vent/Air Intake Connections Ø Inch 4 4
(Ø mm) (110) (110)
Vent Materials PP
Max operating temperature °F 194 194
(°C) (90) (90)
Max HE allowable temperature °F 210 210
(°C) (98.9) (98.9)
Ambient storage temperature °F (5 to 150)
(°C) (-15 to 65)
Ambient functioning temperature °F (32 to 120)
(°C) (0 to 49)
Surface heat exchanger per module SQFT 22 27
(m2)(2) (2.5)
Standard Listings & Approvals CSA, ASME, AHRI
Electrical Req. 120VAC/1Ph-N/60Hz 2 FLA **
Weight (dry) lbs 183 190
(kg) (83) (86)
Dimension WxHxD Inch 26 5/8" x 39 3/8" x 17 1/8"
(mm) (600x1000x435)
(*) with conversion accessory
(**) FLA (Full Load Amperage) – maximum current drawn by the boiler if all pumps reach rated horsepower

12
GENERAL INFORMATION
AHRI certied ratings Unit Condexa PRO
NA 75 P
Condexa PRO
NA 117 P
Input MBH 255.9 399.2
Heating Capacity MBH 243.1 379.2
AFUE %95 95
Combustion Efciency %95 95
CO2 %10.2 - 10.8 9.4 - 9.6
1.9 Pumps
The Condexa PRO NA 75 P and Condexa PRO NA 117 P are equipped
with a built-in circulator.
H [ft.]
0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
0 15 20 25 30105
Q [gpm]
9 CAUTION: During the rst start-up, and at least once a year, the
rotation of the circulator shaft should be checked as, espe-
cially after long periods of not being operated, deposits and/
or residuals could impede its free rotation.
9 CAUTION: Before loosening or removing the circulator cap, pro-
tect the electric devices located underneath from any water
that exits.
0 CAUTION: It is prohibited to operate the circulators without
water.
1.10 Water circuit
2
9
MIRI
1 6 7 8
3
4
5
1 Heat exchanger
2 Pump
3 Drain cock
4 Minimum pressure switch
5 NTC return sensor
6 NTC delivery sensor
7 Safety water high-limit
thermostat temperature
sensor
8 Automatic air vent
9 Flow-meter
MI Central heating supply
RI Central heating return
1.11 Positioning of the temperature sensors
1 Exhaust ue temperature sensor
2 Safety water high-limit thermostat temperature sensor
3 CH supply temperature sensor
4 Return temperature sensor
3
2
1
4

13
GENERAL INFORMATION
1.12 Control panel
CONTROL PANEL AND SYMBOLS
21 3 4 5 6 7 98 10
1 Backlit display (4 13/16" x 1 1/2" / 255mm x 80mm)
2 RESET key: restores normal operations after a safety lock-out
3 MENU key: switches on the main menu
4 ESC key: in menu navigation, it enables you to exit a menu item and go back to the previous one
5 - 9 Navigation keys ◄, ▼, ●, ►, ▲
10 Power switch (located on the bottom left of the appliance)
SECONDARY INFORMATION/DISPLAY VISUALISATION
1
04:29
77.0”°F”
“ CH Setpoint ” 118.4°F ” ”
3
2
1 Outdoor temperature
2 Set-point
3 Clock

14
GENERAL INFORMATION
1.13 Regulations and Guidelines
9 NOTE: Observe all rules, regulations, standards and guidelines
applicable to the installation and operation of this appliance
in your country.
9 NOTE: Valves external to the boiler must be tted with T-han-
dles and condensate piping must be installed in accordance
with the local plumbing code.
1.13.1 Compliance with standards and regulations
The installation must conform to the requirements of the authority
having jurisdiction or, in the absence of such requirements, to the
latest edition of the National Fuel Gas Code, ANSI Z223.1./NFPA 54,
and/or Natural Gas and Propane Installation Code, CAN/CSA B149.1.
This condensing gas boiler complies in its design and mode of
operation with the American National Standard ANSI Z21.13/CSA4.9,
latest edition for Gas Fired Low Pressure Steam and Hot Water Boil-
ers.
Other conrmed approvals and certications are indicated by la-
bels on the boiler.
Where required by the authority having jurisdiction, the installa-
tion must conform to the Standard for Controls and Safety Devices
for Automatically Fired Boilers, ANSI/ASME CSD-1.
Install CO detectors per local regulations. The use of a carbon
monoxide detector in conjunction with the Rheating prod-
ucts is required. When installing a carbon monoxide detector,
the manufacturer’s instructions of the carbon monoxide detector
must be followed in their entirety. It is recommended to use a
carbon monoxide detector in compliance with a nationally rec-
ognized standard such as ANSI/UL 2034-2002 in the United States
and CSA 6.19-01 in Canada. Boiler requires yearly maintenance (see
section "Maintenance")
1.13.2 Operating limits of the boiler
The heat exchanger has been designed and certied in accor-
dance with the ASME Boiler and Pressure Vessel Code, Section IV.
The hot water distribution system must comply with all applicable
codes and regulations. When replacing an existing boiler, it is im-
portant to check the condition of the entire hot water heating dis-
tribution system to ensure safe operation. Common practice calls
for inspecting an existing system in its entirety and bringing it up
to code. All pipework should be properly cleaned and ushed.
1.13.3 Additional regulations for installations in the
Commonwealth of Massachusetts
a) For all side wall horizontally vented gas fueled equipment in-
stalled in every dwelling, building or structure used in whole or in
part for residential purposes, including those owned or operated
by the Commonwealth and where the side wall exhaust vent ter-
mination is less than seven (7) feet above nished grade in the
area of the venting, including but not limited to decks and porch-
es, the following requirements shall be satised:
INSTALLATION OF CARBON MONOXIDE DETECTORS: At the time of in-
stallation of the side wall horizontal vented gas fueled equip-
ment, the installing plumber or gastter shall observe that a hard
wired carbon monoxide detector with an alarm and battery back-
up is installed on the oor level where the gas equipment is to
be installed. In addition, the installing plumber or gastter shall
observe that a battery operated or hard wired carbon monoxide
detector with an alarm is installed on each additional level of the
dwelling, building or structure served by the side wall horizontal
vented gas fueled equipment. It shall be the responsibility of the
property owner to secure the services of qualied licensed pro-
fessionals for the installation of hard wired carbon monoxide de-
tectors.
−In the event that the side wall horizontally vented gas fu-
eled equipment is installed in a crawl space or an attic, the
hard wired carbon monoxide detector with alarm and bat-
tery back-up may be installed on the next adjacent oor
level.
−In the event that the requirements of this subdivision can-
not be met at the time of completion of installation, the
owner shall have a period of thirty (30) days to comply with
the above requirements; provided, however, that during
said thirty (30) day period, a battery operated carbon mon-
oxide detector with an alarm shall be installed.
APPROVED CARBON MONOXIDE DETECTORS: Each carbon monoxide
detector as required in accordance with the above provisions shall
comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certied.
SIGNAGE: A metal or plastic identication plate shall be perma-
nently mounted to the exterior of the building at a minimum
height of eight (8) feet above grade directly in line with the ex-
haust vent terminal for the horizontally vented gas fueled heating
appliance or equipment.
The sign shall read, in print size no less than one-half (1/2) inch in
size, “GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS”.
INSPECTION: The state or local gas inspector of the side wall hor-
izontally vented gas fueled equipment shall not approve the in-
stallation unless, upon inspections, the inspector observes carbon
monoxide detectors and signage installed in accordance with the
provisions of 248 CRM 5.08(2)(a) 1 through 4.
b) EXEMPTIONS: The following equipment is exempt from 248 CRM
5.08(2)(a) 1 through 4:
−The equipment listed in Section 10 entitled “Equipment Not
Required To Be Vented” in the most current edition of NFPA
54 as adopted by the board;
−Product Approved side wall horizontally vented gas fueled
equipment installed in a room or structure separate from
the dwelling, building or structure used in whole or in part
for residential purposes.
c) MANUFACTURERS REQUIREMENTS - GAS EQUIPMENT VENTING SYS-
TEM REQUIRED: When the manufacturer of Product Approved side
wall horizontally mounted gas equipment provides a venting sys-
tem design or venting system components with the equipment,
the instructions provided by the manufacturer for the installation
of the equipment and venting shall include:
−Detailed instructions for the installation of the venting sys-
tem or the venting system components;
−A complete parts list for the venting system design or vent-
ing system.
d) MANUFACTURERS REQUIREMENTS - GAS EQUIPMENT VENTING SYS-
TEM NOT PROVIDED: When the manufacturer of Product Approved
side wall horizontally vented gas fueled equipment does not pro-
vide the parts for the venting of ue gases, but identies “special
venting systems”, the following requirements shall be satised by
the manufacturer:
−The referenced “special venting systems” shall be included
with the appliance or equipment installation instructions;
−The “special venting systems” shall be Product Approved by
the Board and the instructions for that system shall include
a parts list and detailed installation instructions.
e) A copy of all instructions for all Product Approved side wall hor-
izontally vented gas fueled equipment, all venting instructions, all
parts lists for venting instructions and/or venting design instruc-
tions shall remain with the appliance or equipment at the com-
pletion of the installation.

15
INSTALLATION
2 INSTALLATION
2.1 Unpacking the product
The Condexa PRO NA is shipped palletized, packaged and with
cardboard protection.
The following material is supplied in a plastic envelope inside the
package (1):
−Instruction manual
The following material is supplied in a cardboard box inside the
package (2):
−Wall-mount bracket with plugs (no.4 plugs s=0.40" suit-
able for concrete, brick, compact stone and concrete hol-
low brick walls)
−Pressure relief valve
−Condensate drain accessory
9 NOTE: The packaging shows the characteristics of the product:
model, power, fuel type and version. In case of deviation from
the order, contact your local dealer.
After removing the packaging check the condition and
completeness of delivery.
9 WARNING: Keep the packing material out of reach of children
as it may be dangerous.
Dispose of packaging in an environmentally responsible manner.
In order to ensure proper product identication do not remove
or tamper with any product identication tags or labels.
2.1.1 Positioning of labels
A
A
CALDAIA MURALE A GAS
WALL HUNG GAS BOILER
CHAUDIERE MURALE A GAZ
GAS - WANDHEIZKESSEL
IT
GB
FR
D
CALDAIA MURALE A GAS
WALL HUNG GAS BOILER
CHAUDIERE MURALE A GAZ
GAS - WANDHEIZKESSEL
IT
GB
FR
D
1
2
A Packing label
9 NOTE: The instruction manual is an integral part of the appli-
ance; therefore, it should be read and stored carefully.
9 NOTE: Keep the documentation envelope in a safe place. Any
replacement documents must be ordered from Riello S.p.A.
who reserve the right to charge for the cost of the replacement.
2.2 Overall dimensions and weights
P
H
L
Description Condexa PRO NA 75 P Condexa PRO NA 117 P
L23 5/8" (600mm) 23 5/8" (600mm)
P17 1/8" (415mm) 17 1/8" (415mm)
H39 3/8" (1000mm) 39 3/8" (1000mm)
Net weight 183 lbs (83 kg) 190 lbs (86 kg)

16
INSTALLATION
2.3 Installation premises
The Condexa PRO NA can be installed in rooms that are perma-
nently ventilated and equipped with suitably sized ventilation
openings in line with Technical Standards and Regulations appli-
cable to the installation site.
9 WARNING: When installing the boiler, allow sufcient space
around it to access all safety and control devices and to permit
easy maintenance.
9 WARNING: Check that the electric protection level of the appli-
ance is suitable for features of the room where it is installed.
9 WARNING: Make sure that comburent air is not contaminat-
ed by substances containing chlorine or uorine (elements
found in sprays, paints, detergents etc.).
0 WARNING: Do not obstruct or restrict the air vents in the room
where the boiler is installed. A free air supply is essential for
correct combustion.
0 WARNING: It is forbidden to leave ammable containers and
substances in the room where the boiler is installed.
2.3.1 Installation clearances
Recommended minimum clearances for installation and servicing
(dimensions in inches [mm]).
≥ 40"
(1000mm)
≥ 34"
(850mm)
≥ 16"
(406mm)
≥ 20"
(500mm)
≥ 20"
(500mm)
The minimum surface of ventilation openings is 3.2ft2(0.3m2) for
gas fuel heating systems.
2.4 Installation in older systems and systems
requiring modications
When installing these boilers in older systems or systems requiring
modications, always perform the following checks:
−Make sure that the ue is able to withstand the tempera-
ture of the combustion gases and that it has been designed
and made in compliance with applicable standards. The
ue must also be as straight as possible, sealed, insulated
and not blocked or choked. See section "Combustion gas
exhaust" for any additional information.
−Make sure that the electrical supply system has been in-
stalled by a qualied electrician in compliance with appli-
cable standards
−Make sure that the fuel feed line and any storage tank are
made and installed in compliance with applicable stan-
dards
−Make sure that expansion tank(s) are big enough to contain
the additional volume generated by thermal expansion
−Make sure that the ow rate, head and direction of ow of
the pumps are suitable and correct
−The system has been washed, cleaned of mud and grime
and water seals have been checked
−A treatment system is tted when the supply/rell water
has values other than those indicated in Paragraph "Water
Chemistry Guidelines"
9 NOTE: The manufacturer declines all responsibility for damage
caused by incorrectly constructed ue systems.
2.5 Moving and removing the packaging
9 NOTE: Do not remove the cardboard packaging until your reach
the installation location.
9 Before handling the appliance and removing the packaging,
wear personal protective equipment (PPE) and use tools suit-
able for the appliance's size and weight.
9 This step must be carried out by several individuals equipped
with suitable means with respect to the appliance's size.
Make sure that the load is not unbalanced during handling.
Proceed as follows to remove the packing:
−Remove the strapping that secures the cardboard packag-
ing to the pallet
−Remove the cardboard
−Remove edge protectors (1)
−Remove the Styrofoam protection (2)
−Remove the protective bag (3)
3
1
2
1
1

17
INSTALLATION
2.6 Boiler assembly
The Condexa PRO NA boilers are supplied complete with a
wall-mounting bracket.
9 CAUTION: Check that the wall on which the appliance is to
be tted is sufciently solid and supports safe screw xing
points.
9 NOTE: The appliance's height must be selected so as to facili-
tate dismantling it and maintaining it.
H
Model Height (H) ft
Condexa PRO NA 75 P 6<H<6.5
Condexa PRO NA 117 P 6<H<6.5
For installation:
−Position the bracket (1) onto the wall (2), at the point where
you wish to install the appliance
−Ensure that the bracket is level and mark the points where
the holes for xing plugs must be drilled
−Drill the holes and insert expansion plugs
−Note: Drill bit size should be 3/8"(10mm) for expansion
plugs (3).
−Fix the bracket to the wall using the screws (4)
−Secure the appliance to the bracket
1
2
3
4
After installing the boiler:
−remove the locking screw at the bottom of the boiler.
−pull the front panel outwards and then to the top to re-
move it from points A.
−remove the plostyrene block under heat exchanger.
A
A
Close the panelling in reverse order to the one described above.
9 NOTE: Before proceeding with the hydraulic connections the
protection plugs must be removed from the supply, return
and condensate drain piping.

18
INSTALLATION
2.7 Water connections
The dimensions and position of boiler's hydraulic connections are shown in the table below.
Front view Bottom view
RI MI
D
E
F
B
A
C
DESCRIPTION Condexa PRO NA 75 P Condexa PRO NA 117 P
A15 3/16" (386mm) 15 3/16" (386mm)
B5 5/8" (142mm) 5 5/8" (142mm)
C2 1/2" (64mm) 2 1/2" (64mm)
D11 1/8" (282mm) 11 1/8" (282mm)
E3 15/16" (99mm) 3 15/16" (99mm)
F3 5/8" (91mm) 3 5/8" (91mm)
MI (system supply) NPT 1" 1/2 M NPT 1" 1/2 M Ø / inch
RI (system return) NPT 1" 1/2 M NPT 1" 1/2 M Ø / inch
SC (condensate drain) 1" 1" Ø / inch
G (gas inlet) NPT 1" 1/4 M NPT 1" 1/4 M Ø / inch
9 NOTE: Before connecting the boiler the protection plugs must
be removed from the supply, return and condensate drain
pipes.
9 CAUTION: Before connecting the boiler, it is necessary to clean
the system. This step is required when the appliance replaces
another one on pre-existing systems.
In order to carry out this cleaning activity, if the old boiler is still
installed on the system, it is advisable to:
−add a de-scaling additive.
−Operate the system with the boiler on for around 7 days.
−Discharge the dirty system water and ush the system one
or more times with clean water.
If the system is very dirty, repeat the last procedure one more time.
If the old boiler is not present or available, use a pump to circulate
the water + additive through the system for about 10 days and
perform a nal washing as described in the previous paragraph.
Once the cleaning has been completed, it is recommended to add
a suitable protective uid to the system's water before installing
the boiler.
In order to clean the heat exchanger's built-in water system,
please contact your local Rboiler distributor for further assis-
tance.
0 CAUTION: Do not use incompatible liquid detergents, including
acids (for instance, chloridric acid and similar) in any concen-
tration.
0 CAUTION: Do not subject the heat exchanger to cyclical pres-
sure changes because fatigue stress is very dangerous for the
integrity of system components.
The boiler, when used in connection with a refrigeration system,
must be installed so the chilled medium is piped in parallel with
the boiler with appropriate valves to prevent the chilled medium
from entering the boiler.
The boiler piping system of a hot water boiler connected to heat-
ing coils located in air handling units where they may be exposed
to refrigerated air circulation must be equipped with ow control
valves or other automatic means to prevent gravity circulation of
the boiler water during the cooling cycle.

19
INSTALLATION
2.8 ASME pressure relief valve
The Condexa PRO NA has a pressure relief valve supplied with the
boiler.
Connect the valve hydraulically on the heating supply connection
and in vertical position.
This device is designed for emergency safety relief and shall not be
used as an operating control.
9 WARNING To avoid water damage or scalding due to relief
valve operation:
−The discharge line must be connected to relief valve outlet
and run to a safe place of disposal. Terminate the discharge
line in a manner that will prevent possibility of severe burns
or property damage.
−The discharge line must be as short as possible and be the
same size as the valve discharge connection throughout its
entire length.
−The discharge line must pitch downward from the valve
and terminate at least 6’’ (152 mm) above the oor drain
where any discharge will be clearly visible.
−The discharge line shall terminate through plain (unthread-
ed) pipe. The discharge line material must conform to local
plumbing code or A.S.M.E. requirements.
−No shutoff valve shall be installed between the relief valve
and the boiler, or in the discharge line.
−Do not pipe the discharge to any place where freezing
could occur.
−Do not plug or place any obstruction in the discharge line.
−Test the operation of the valve after lling and pressurizing
system by lifting the lever. Make sure the valve discharges
freely. If the valve fails to operate correctly, replace it with
a new relief valve.
−For boilers installed with only a pressure relief valve, the
indirect tank (if used) must have a temperature and pres-
sure relief valve installed. This relief valve shall comply with
the standard for Relief Valves for Hot Water Supply Systems,
ANSI Z21.22/CSA4.4.
−Failure to comply with the above guidelines could result in
the failure of the relief valve to operate, resulting in the
possibility of severe personal injury, death or substantial
property damage.
−For safe operation of the appliance, the relief valve must
not be removed or plugged.
Maintenance of the relief valve
9 CAUTION : The valve lever must be operated at least once a year
by qualied personnel during annual maintenance to insure
that water-ways are clear.
Certain natural occurring mineral deposits may adhere to the
valve, rendering it inoperative.
When manually operating the lever, water will discharge and pre-
cautions must be taken to avoid contact with hot water to avoid
water damage.
Before operating the lever, check to see that a discharge line is
connected to this valve directing the ow of hot water from the
valve to drain otherwise personal injury may result. If no water
ows, the valve is inoperative. Call a qualied plumber immedi-
ately.
Pressure relief valve should be inspected at least once every three
years by a licensed plumbing contractor or authorized inspection
agency, to insure that the product has not been affected by cor-
rosive water conditions and to insure that the valve and discharge
line have not been altered or tampered with illegally.
Certain naturally occurring conditions may corrode the valve or its
components over time, rendering the valve inoperative.
Such conditions are not detectable unless the valve and its com-
ponents are physically removed and inspected.
Do not attempt to conduct this inspection on your own. Contact
your plumbing contractor for a reinspection to assure continuing
safety.
9 WARNING : Failure to reinspect this valve as directed could
result in unsafe pressure buildup which can result in serious
injury or death and/or severe property damage.
2.9 Low Water Cutoff
A low water cutoff may be required by state local code or some in-
surance companies. Check code requirements before installation
of the Condexa PRO NA boiler.
If required:
−Use a low water cutoff designed for hydronic installations
−Follow low water cutoff manufacturer’s instructions
A hot water boiler installed above the radiation level or as re-
quired by the Authority having jurisdiction, must be provided with
a low water cutoff device either as part of the boiler or at the time
of boiler installation.
9 NOTE: The electronic low water cutoff located internally in the
Condexa PRO NA is below the lowest safe permissible water
level established by the boiler manufacturer.

20
INSTALLATION
2.10 Typical water system schematics
Layout 1: circuit with boiler directly linked to heating system (check that the pump's discharge head is sufcient to ensure ade-
quate circulation)
8 7
EAF
MI
21
RI
1
11
12
OS
CONDEXA PRO
North America
5
6
4
Layout 2: circuit with boiler directly linked to heating system and indirect DHW tank. (check that the pump's discharge head is
sufcient to ensure adequate circulation)
CONDEXA PRO
North America
5
UAC
1781
EAF
6
11
10
1
1
2
34
9
8 7
EAF
MI
21
RI
1
11
OS
6
12
5
6
4
1 Isolating valve
2 Check valve
3 DHW circulation pump
4 Expansion tank
5 Pressure relief valve
6 Drain
7 Water softener lter
8 Pressure reducer
9 Domestic water storage tank
10 Automatic air vent
11 Diverter valve
12 Pump
13 High-temperature system circulator
14 Indirect tank circulator
OS Outdoor temperature
sensor
MI High temperature system
supply
RI High temperature system
return
EAF Domestic cold water inlet
UAC Domestic hot water outlet
9 WARNING: Domestic hot water and central heating circuits must be completed with expansion tanks of adequate capacity and suit-
ability, correctly-sized pressure relief valves. The discharge of pressure relief valves and appliances must be connected to a suitable
collection and disposal system.
9 CAUTION: 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 expertise to ensure proper installation and functioning in conformity to all applicable legislation.
9 CAUTION: Special supply/rell water must be conditioned using suitable treatment systems.
0 WARNING: It is prohibited to operate the boiler without water.