Riello Array AR 3000 User manual

cod. Doc-0079789 rev. 3 11/2016
Array AR 3000 - AR 4000
US INSTALLATION AND OPERATION MANUAL

2
Dear heating engineer,
Congratulations for proposing a Rboiler. This appliance ensures
maximum comfort for an extended period, with high reliability,
efciency, quality and safety.
This manual provides information that is essential to the in-
stallation of the appliance. Used in conjunction with your own
knowledge and expertise it will enable you to install the appliance
quickly, easily, and correctly.
Please accept our thanks and our congratulations on your choice
of product.
RS.p.A.
CONFORMITY
Commercial Boilers
AHRI Standard BTS-2000
The information contained in this manual is subject to change
without notice from RSpA. Rmakes no warranty of any kind
with respect to this material, including but not limited to implied
warranties of merchantability and tness for a particular appli-
cation. Ris not liable for errors appearing in this manual. Nor
for incidental or consequential damages occurring in connection
with the furnishing, performance, or use of this material.
ENGLISH
RANGE
MODEL CODE
Array AR 3000 20115025
Array AR 4000 20115026
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 appli-
ance.
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 re depart-
ment.
Qualied installer, service agency or the gas supplier must per-
form installation and service.
9
FOR YOUR SAFETY: Improper installation and/or operation
could create carbon monoxide gas in ue gases which could
cause serious injury, property damage, or death. Improper in-
stallation and/or operation will void the warranty.

3
This manual, Cod Doc-0079789 - Rev.3(11/2016) comprises 68 pages
1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Warnings & cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Emergency shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 Prolonged shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Receiving the unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Site preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.4.1 Installation clearances . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4.2 Setting the Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.5 Boiler location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.6 Supply and return piping . . . . . . . . . . . . . . . . . . . . . . . . 9
2.7 Low water cutoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.8 High limit safety switch . . . . . . . . . . . . . . . . . . . . . . . . 10
2.11.1 Gas Supply Specications . . . . . . . . . . . . . . . . . . . . . .11
2.11.2 Manual Gas Shutoff Valve . . . . . . . . . . . . . . . . . . . . . . 11
2.11.3 External Gas Supply Regulator. . . . . . . . . . . . . . . . . . 12
2.11.4 Gas Type Conversion . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.11.5 Adjusting and setting CO2limits. . . . . . . . . . . . . . . . . 13
2.12 AC electrical power wiring . . . . . . . . . . . . . . . . . . . . . . 13
2.12.1 Electrical Power Requirements . . . . . . . . . . . . . . . . . 14
2.13 Field control wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.13.1 Room Thermostat Connection (Enable/Disable) . . . . . 15
2.13.2 Air Damper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.13.3 Outdoor Temperature Sensor. . . . . . . . . . . . . . . . . . . 15
2.14 Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.15 Combustion air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.15.1 Combustion air from outside the building. . . . . . . . . 20
2.15.2 Combustion air from inside the building. . . . . . . . . . 20
2.15.3 Ducted combustion air . . . . . . . . . . . . . . . . . . . . . . . 20
3 COMMISSIONING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.4.1 Conrming the Unit’s Gas Type . . . . . . . . . . . . . . . . . 21
3.4.2 Gas Type Conversion . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.5 Boiler startup procedure . . . . . . . . . . . . . . . . . . . . . . . 22
3.5.1 Minimum Water Flow (Heat Exchanger Protection) . . 23
3.5.2 Heating System Pressure Test. . . . . . . . . . . . . . . . . . . 23
3.6 Boilers’ cascade installation and start-up . . . . . . . . . . 24
3.6.1 Boilers Cascade: Set Boiler Address . . . . . . . . . . . . . . 24
3.6.2 Boilers Cascade: Set Power switch S1 . . . . . . . . . . . . 24
4 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.3 Touchscreen control panel menus . . . . . . . . . . . . . . . . 25
4.3.1 Riello Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.3.2 Cascade Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.3.3 Boiler Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.3.4 Module Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.3.5 Performance Screen . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.3.6 Error Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.3.7 Service Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.3.8 Module Test Screen . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5 SHUTDOWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.1 Shutting down the heating system. . . . . . . . . . . . . . . . 28
5.2 Shutting down the heating system in an emergency . . 28
6 ENVIRONMENTAL PROTECTION/DISPOSAL. . . . . . . . . . 28
APPENDIX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Appendix A - Wiring diagram. . . . . . . . . . . . . . . . . . . . . . . . 29
Appendix B - Size and connections . . . . . . . . . . . . . . . . . . . 34
Appendix C - Connection diagram . . . . . . . . . . . . . . . . . . . . 35
Appendix D - Technical data . . . . . . . . . . . . . . . . . . . . . . . . 37
Appendix E - Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Appendix F - Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 40
Appendix G - Head available for the system . . . . . . . . . . . . 41
Appendix H - De-rating for altitude installation . . . . . . . . . 42
Appendix I - Efciency Curves . . . . . . . . . . . . . . . . . . . . . . . 43
Appendix J - Troubleshooting table . . . . . . . . . . . . . . . . . . . 44
Appendix K - BOILER Installation (example drawings) . . . . . 50
Appendix L - Ladder diagram . . . . . . . . . . . . . . . . . . . . . . . 52
Appendix M - Venting size data . . . . . . . . . . . . . . . . . . . . . . 63
Appendix N - Exhaust terminals and Air inlet Clearances . . . 64
Appendix O - Sensor Resistance. . . . . . . . . . . . . . . . . . . . . . 66
The following symbols are used in this manual:
9
CAUTION! = Identies actions that require caution and ad-
equate preparation.
0
STOP! = Identies actions that you MUST NOT do.
CONTENTS

4
GENERAL
1 GENERAL
The RArray AR 3000 and AR 4000 MBH Boilers are modulating
and condensing units. They represent a true industry advance that
meets the needs of today’s energy and environmental concerns.
Designed for application in any closed loop hydronic system, the
Array’s modulating capability matches energy input directly to
uctuating system loads. The turn down ratio for these models
is 30:1 for AR 3000 and 40:1 for AR 4000. These Array models pro-
vide extremely high efciency operation and are ideally suited for
modern low temperature, as well as, conventional heating sys-
tems.
The Array Models AR 3000 and AR 4000 operate within the follow-
ing input and output ranges:
Array
model
Input Range (BTU/hr.) Output Range(*) (BTU/hr.)
Minimum Maximum Minimum Maximum
AR 3000 100,000 3,000,000 96,100 2,883,000
AR 4000 100,000 4,000,000 96,100 3,844,000
(*) The output of the boiler is a function of the unit’s ring rate,
return water temperature and BTU content of gas supply.
Array Series of hot water boilers has been designed in compliance
with the CSD-1 code.
When installed and operated in accordance with this Instruction
Manual, these boilers comply with the NOx emission standards
outlined in:
South Coast Air Quality Management District (SCAQMD), Rule 1146.2
Whether used in singular or modular arrangements, the AR 3000
and AR 4000 offer the maximum venting exibility with mini-
mum installation space requirements. These Boilers are Category
IV, positive pressure appliances. Single and/or multiple breeched
units are capable of operation in the following vent congura-
tions:
− Conventional, Vertical Conventional,
− Sidewall Conventional, Direct Vent,
− Vertical Sealed, Direct Vent, Horizontal
These boilers are capable of being vented utilizing PP, CPVC, Stain-
less steel AL29-4C vent systems.
The Array’s advanced electronics are available in several selectable
modes of operation offering the most efcient operating methods
and energy management system integration.
9
IMPORTANT: Unless otherwise specied, all descriptions and
procedures provided in this Installation & Operation Manual
apply to the Array series of boiler.
1.1 Warnings & cautions
Installers and operating personnel MUST, at all times, observe all
safety regulations. The following warnings and cautions are gen-
eral and must be given the same attention as specic precautions
included in these instructions.
In addition to all the requirements included in this RInstruc-
tion Manual, the installation of units MUST conform with local
building codes, or, in the absence of local codes, ANSI Z223.1 (Na-
tional Fuel Gas Code Publication No. NFPA-54) for gas-red boilers
and ANSI/NFPASB for LP gas-red boilers.
Where applicable, the equipment shall be installed in accordance
with the current Installation Code for Gas Burning Appliances and
Equipment, CSA B149.1, and applicable Provincial regulations for
the class; which should be carefully followed in all cases.
Authorities having jurisdiction should be consulted before instal-
lations are made.
See pages 10 - 11 for important information regarding installation of
units within the Commonwealth of Massachusetts.
9
IMPORTANT: This Instruction Manual is an integral part of the
product and must be maintained in legible condition. It must
be given to the user by the installer and kept in a safe place
for future reference.
9
WARNING: Do not use matches, candles, ames, or other
sources of ignition to check for gas leaks.
9
WARNING: Fluids under pressure may cause injury to person-
nel or damage to equipment when released. Be sure to shut
off all incoming and outgoing water shutoff valves. Careful-
ly decrease all trapped pressures to zero before performing
maintenance.
9
WARNING: Before attempting to perform any maintenance on
the unit, shut off all gas and electrical inputs to the unit.
9
WARNING: The exhaust vent pipe of the unit operates under
a positive pressure and therefore must be completely sealed
to prevent leakage of combustion products into living spaces.
9
WARNING: Electrical voltages up to 230 vac maybe used in this
equipment. Therefore the cover on the unit’s power box (lo-
cated behind the front panel door) must be installed at all
times, except during maintenance and servicing.
9
CAUTION: Many soaps used for gas pipe leak testing are cor-
rosive to metals. The piping must be rinsed thoroughly with
clean water after leak checks have been completed.
0
CAUTION: DO NOT use this boiler if any part has been under wa-
ter. Call a qualied service technician to inspect and replace
any part that has been under water.

5
GENERAL
1.2 Emergency shutdown
If overheating occurs or the gas supply fails to shut off, close the
manual gas shutoff valve (Fig. 1) located external to the unit.
NOTE: The Installer must identify and indicate the location of the
emergency shutdown.
Fig. 1 Manual Gas Shutoff Valve
1.3 Prolonged shutdown
After prolonged shutdown, it is recommended that the startup
procedures and the safety device test procedures of this manual
be performed, to verify all system-operating parameters.
If there is an emergency, turn off the electrical power supply to the
Rboiler and close the manual gas valve located upstream the
unit. The installer must identify the emergency shut-off device.
IMPORTANT - FOR MASSACHUSETTS INSTALLATIONS
Boiler Installations within the Commonwealth of Massachusetts
must conform to the following requirements:
− Boiler must be installed by a plumber or a gas tter who is
licensed within the Commonwealth of Massachusetts.
− Prior to unit operation, the complete gas train and all con-
nections must be leak tested using a non-corrosive soap.
− The vent termination must be located a minimum of 4 feet
above grade level. If side-wall venting is used, the installa-
tion must conform to the following requirements extracted
from 248 CMR 5.08 (2):
(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:
1. INSTALLATION OF CARBON MONOXIDE DETECTORS
At the time of installation of the side wall horizontal vented gas
fueled equipment, the installing plumber or gastter shall ob-
serve 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, build-
ing or structure served by the side wall horizontal vented gas fu-
eled equipment. It shall be the responsibility of the property own-
er to secure the services of qualied licensed professionals for the
installation of hard wired carbon monoxide detectors.
a. In the event that the side wall horizontally vented gas fueled
equipment is installed in a crawl space or an attic, the hard
wired carbon monoxide detector with alarm and battery back-
up may be installed on the next adjacent oor level.
b. In the event that the requirements of this subdivision cannot
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)
days period, a battery operated carbon monoxide detector
with an alarm shall be installed.
2. 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.
3. SIGNAGE
A metal or plastic identication plate shall be permanently
mounted to the exterior of the building at a minimum height of
eight (8) feet above grade directly in line with the exhaust 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”.
4. INSPECTION
The state or local gas inspector of the side wall horizontally vented
gas fueled equipment shall not approve the installation unless,
upon inspection, the inspector observes carbon monoxide detec-
tors and signage installed in accordance with the provisions of 248
CMR 5.08(2)(a)1 through 4.
(b) EXEMPTIONS:
The following equipment is exempt from 248 CMR 5.08(2)(a)1
through 4:
1. The equipment listed in Chapter 10 entitled “Equipment Not
Required To Be Vented” in the most current edition of NFPA 54
as adopted by the Board; and
2. 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 res-
idential purposes.

6
GENERAL
(c) MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYS-
TEM PROVIDED
When the manufacturer of Product Approved side wall horizon-
tally vented gas equipment provides a venting system design or
venting system components with the equipment, the instructions
provided by the manufacturer for installation of the equipment
and the venting system shall include:
1. Detailed instructions for the installation of the venting system
design or the venting system components; and
2. A complete parts list for the venting system design or venting
system.
(d) MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYS-
TEM NOT PROVIDED
When the manufacturer of a Product Approved side wall horizon-
tally vented gas fueled equipment does not provide the parts for
venting the ue gases, but identies “special venting systems”,
the following requirements shall be satised by the manufacturer:
1. The referenced “special venting system” instructions shall be
included with the appliance or equipment installation instruc-
tions; and
2. 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 installation instructions for all Product Approved
side wall horizontally vented gas fueled equipment, all venting in-
structions, all parts lists for venting instructions, and/or all venting
design instructions shall remain with the appliance or equipment
at the completion of the installation.
[End of Extracted Information From 248 CMR 5.08 (2)]
2 INSTALLATION
2.1 Introduction
This Chapter provides the descriptions and procedures neces-
sary to unpack, inspect and install the RArray Boiler Model
AR 3000 and AR 4000.
2.2 Receiving the unit
Each Array Boiler System is shipped as a single crated unit. The unit
must be moved with the proper lifting equipment for safety and to
avoid equipment damage. The unit should be completely inspect-
ed for evidence of shipping damage and shipment completeness
at the time of receipt from the carrier and before the bill of lading
is signed.
NOTE: Ris not responsible for lost or damaged freight. Any vi-
sual damage to the packaging materials should be made clear to
the delivering carrier.
2.3 Unpacking
Carefully unpack the unit, pay particular attention not to damage
the unit enclosure when cutting away packaging materials.
After unpacking, a close inspection of the unit should be made
to ensure that there is no evidence of damage. The freight carrier
should be notied immediately if any damage is detected.
The following accessories come standard with each unit and are
either packed separately within the unit’s shipping container or
are factory installed on the unit:
− Pressure/Temperature Gauge
− ASME Pressure Relief Valves
− Condensate Drain Traps
− Outdoor Sensor
− System Supply Sensor (length: 20”)
− Connection Cable between 905PB internal display and
905MN boards
− Venting adapter 10” down to 8”
− Stainless steel air intake adapter 8”
When optional accessories are ordered, they may be packed with-
in the unit’s shipping container, factory installed on the unit, or
packed and shipped in a separate container. Any standard or op-
tional accessories shipped loose should be identied and stored
in a safe place until ready for installation or use.
2.4 Site preparation
Ensure that the site selected for installation of the Array AR 3000
and AR 4000 Boiler includes:
− Access to AC Input Power at 230 VAC, Phase-Phase-Neutral,
60 Hz @ 24 FLA
− Access to Natural Gas line at a recommended minimum
pressure of 8 inches W.C. for 3,000,000 BTU/hr energy input
for the AR 3000 OR 4,000,000 BTU/hr energy input for the
AR 4000.

7
INSTALLATION
2.4.1 Installation clearances
The Array models AR 3000 and AR 4000 are packaged in an enclo-
sure having identical size.
The unit must be installed with the prescribed clearances for ser-
vice as shown in Fig. 2. The minimum clearance dimensions, re-
quired by R, are listed below. However, if Local Building Codes
require additional clearances, these codes shall supersede R’s
requirements. Minimum acceptable clearances required are as
follows:
Minimum acceptable clearances required are as follows:
− Sides: 24 inches
− Front: 31.5 inches
− Rear: 24 inches
− Top: 24 inches
All gas piping, water piping and electrical conduit or cable must
be arranged so that they do not interfere with the removal of any
panels, or inhibit service or maintenance of the unit.
24
”2
4”
31.5” 24”
24”
72.8”
83”
Fig. 2 Array AR 3000, AR 3000 Clearances
9
WARNING: Keep the unit area clear and free from all combus-
tible materials and ammable vapors or liquids.
9
CAUTION: While packaged in the shipping container, the unit
must be moved by pallet jack or forklift from the SIDE ONLY.
FOR MASSACHUSSETTS ONLY:
For Massachusetts installations, the unit must be installed by a
plumber or gastter licensed within the Commonwealth of Mas-
sachusetts. In addition, the installation must comply with all re-
quirements specied in “Warnings & cautions” pag. 4.
2.4.2 Setting the Unit
Remove the top and side wooden panels, the plastic lm and the
polystyrene sheets. Remove the lag screws securing the unit to the
shipping skid. Lift the unit off the shipping skid with a forklift and
position it on the oor in the desired location.
9
WARNING: When lifting or moving the boiler: do not attempt
to manipulate the boiler using the top water anges or any
other component of the boiler.
9
WARNING: When lifting or moving the boiler with a forklift:
make sure the forks are longer than the boiler size (width or
depth) so that forks stick out as per Fig. 3.
Fig. 3 Array AR 3000 and AR 4000 Forklift Handling
If a crane is required, the boiler must be lifted through bands.
9
WARNING: When lifting the boiler with crane: use bands, no
chains. Bands must comply with federal, state and local rules.
9
WARNING: When lifting the boiler with crane: the bands must
be positioned according to the Fig. 4.

8
INSTALLATION
In multiple unit installations, it is important to plan the position
of each unit in advance. Sufcient space for piping connections
and future service/maintenance requirements must also be taken
into consideration. All piping must include ample provisions for
expansion.
13.8”29.9”
FRONT
Fig. 4 Array AR 3000 and AR 4000 Crane Lifting Handling
The unit must be installed on a concrete at oor, with no gra-
dient in any direction, to ensure proper condensate and water
drainage (see Fig. 5). If anchoring the unit, refer to Fig. 6 for an-
chor locations.
Fig. 5 Array AR 3000 and AR 4000 Installation
32.9”
2.8”
2.8”
70.3”
Fig. 6 Array AR 3000 and AR 4000 Anchoring bolts
2.5 Boiler location
− This boiler is suitable for indoor installations.
− To operate properly and safely this boiler requires a con-
tinuous supply of air for combustion. Install this boiler in a
clean, dry location with adequate air supply.
− Do not locate this boiler in an area where it will be subject
to freezing.
− The boiler should be located close to a oor drain in an
area where leakage from the appliance or connections will
not result in damage to the adjacent area or to lower oors
in the structure.
− DO NOT install this appliance in any location where gasoline
or ammable vapors are likely to be present.
− DO NOT install this appliance on top of carpet ooring.
− Appliance must be installed on a level oor.
− Maintain required clearances from combustible surfaces.

9
INSTALLATION
2.6 Supply and return piping
The Array Boiler utilizes 4” anges, for both models AR 3000 and
AR 4000,for the water system supply and return piping connec-
tions. The physical location of the supply and return piping con-
nections is on the top of the unit as shown in Fig. 7.
Water
Return
Gas
connection
Water
Supply
Fig. 7 Array AR 3000 and AR 4000 Connections
Excessive water hardness causing a lime buildup in the stainless
steel coils or tubes is not a fault of the appliance and is not cov-
ered by warranty. Water hardness must fall within the following
limits:
STEEL BOILERS - With furnace power > 500kBTU/h
Water used
for rst lling
Water with
system operating
ph 6 - 8 7.5 – 9.5
Hardness ppm < 50 < 50
Electrical Conduc-
tivity ppm < 67
Chlorides ppm < 10
Sulphides ppm < 10
Nitrides ppm < 10
Oxygen in Solution ppm
Iron ppm < 0.5
− Use only untreated water to ll the system.
− Do not use TSP (tri-sodium phosphate).
− Do not use ll water treated with salt bedding type ex-
changers (ion exchanger).
− Never introduce non-approved boiler treatment or similar
additives.
− Consult a local water treatment specialist for recommenda-
tions if any of the above is outside the stated ranges.
− When using oxygen permeable PEX, the system must be
separated from the boiler by a heat exchanger.
− A correctly sized and working expansion vessel must be in-
stalled.
− Do not exceed the maximum permissible ow rate through
the boiler. Excessive ow can cause erosion damage to the
heat exchanger.
9
CAUTION: Before connecting the boiler to the heating system,
ush the heating system to remove sediment, ux, dirt, and
other foreign matter. The heat exchanger may be damaged by
sediment or corrosion.
9
CAUTION: Do not use cleaning uids that are not compatible
with the boiler materials, including acids (e.g. hydrochloric
acid and similar ones) at any concentration.
9
CAUTION: Introducing fresh water to the system increases the
oxygen presence and can cause corrosion of metallic compo-
nents. Immediately repair any drips or leaks in the system to
avoid constant introduction of air into the system.
9
CAUTION: Excessive uctuation in pressure changes in the sys-
tem can cause fatigue and stress on the heat exchanger. This
is detrimental to the integrity of the boiler and system com-
ponents, it is mandatory to maintain a constant operating
pressure.
9
CAUTION: For freeze protection use only propylene glycol, with
scale inhibitors, with a maximum volume [concentration] of
50% of glycol. Frost protection and inhibitor level has to be
checked annually during the regular scheduled maintenance
of the condensing boiler.
A minimum water pressure is required for optimum performance.
Minimum water pressure required: 7.25 psi (0.5 bar).

10
INSTALLATION
2.7 Low water cutoff
A low water cut off (LWCO) is installed on each boiler.
To check the functionality of LWCO go to the 905PB inner display,
access the Settings menu, select Test mode, and then click on
LWCO1. On the screen will appear the error “MN: Low Water Cutoff
Error”.
At this point press the reset button. The error will turn off.
2.8 High limit safety switch
A high limit safety switch is installed on each module of the boiler.
To simulate a high limit lockout at 208°F go to the 905PB inner
display, access the Settings menu, select Test mode, then click on
Max temp.
The control will display “MN: Max. Thermostat Lock Error”.
At this point press the reset button on the removable display to
restart the module.
2.9 Pressure relief valve installation
ASME rated Pressure Relief Valves are factory installed in each Array
Boiler. The pressure rating for the relief valves is 75 PSI. The relief
valves are installed on each hot water horizontal manifold of the
boiler as shown in Fig. 8. The relief valves drain piping must be
connected to a nearby oor drain. In multiple unit installations
the discharge lines must not be manifolded together.
Each must be individually run to a suitable discharge location.
Relief valves should be manually operated at least once a year.
If a relief valve discharges periodically, this may be due to thermal
expansion in a closed water supply system.
Contact the water supplier or local plumbing inspector on how to
correct this situation.
Do not plug the relief valve.
75PSI Relief valve
(one for each pair
of modules)
Fig. 8 Pressure Relief Valve Location
2.10 Condensate drain and piping
The Array Boiler is designed to condense water vapor from the ue
products. Each module of the boiler is equipped with a conden-
sate trap (see Fig. 9), while a syphon collects the condensate of the
vertical ue manifold.
Vertical Flue
Manifold
Syphon
Condensate
Trap
Condensate
Trap
Condensate
Trap
Condensate
Trap
Fill the syphon with
water from the top
of the vertical flue
manifold BEFORE
to connect the vent
piping
Fig. 9 Condensate Drain System
9
WARNING: At the Start-up and after prolonged shutdown of
the boiler, the condensate traps and the syphon must be lled
with water prior to restart it, otherwise combustion gases will
enter the room with a risk of an excessive level of carbon
monoxide.

11
INSTALLATION
The procedure for lling the traps and syphon with water is shown
on the Fig. 10:
Vertical Flue
Manifold
Syphon
Disconnect the
condensate pipe
Fill the trap
with water
Fill the syphon
with water from
the top of the
vertical flue
manifold
BEFORE to
connect the
vent piping
Fig. 10 Water Filling of Condensate System
− The installation must have provisions for suitable drainage
or collection of the condensate out of the boiler traps.
− The condensate water shall be discharged at atmospher-
ic pressure, by dripping into a suitable drain, and shall be
neutralized prior to draining per local codes.
− The condensate drain tube must pitch away from the boiler
(1/4” slope per foot) and must never reduce its diameter
downstream.
− Never use copper pipes or of other material not intended
for the specic purpose, because the action of condensate
will cause a rapid deterioration.
− Check that the condensate drain pipe is adequately sloping
towards the discharge point avoiding high points, which
can inhibit the ow of condensate. The condensate pipe
must be installed in such a way so as to avoid the freezing
of the liquid.
9
WARNING: Verify condensate disposal / neutralization is in ac-
cordance with local, state and federal regulations.
If a oor drain is not available, a condensate pump can be used to
remove the condensate to drain. The maximum condensate ow
rate is 23.8 GPH for Array AR 3000 and 31.7 GPH for Array AR 4000.
The drain line must be removable for routine maintenance.
9
CAUTION: Use PVC, CPVC, stainless steel, aluminum or polypro-
pylene for condensate drain piping (Fig. 10). DO NOT use car-
bon or copper components.
Relief Valves
Manifold
Condensate
Drain
Fig. 11 Condensate Drain and Relief Valves Manifold Locations
2.11 Gas supply piping
Array AR 3000 and AR 4000 boilers contain a 2 inch NPT gas inlet
connection on the top of the unit as shown in Fig. 7.
9
WARNING: Never use matches, candles, ames or other sourc-
es of ignition to check for gas leaks.
9
CAUTION: Many of the soaps used for gas pipe leak testing are
corrosive to metals. Therefore, piping must be rinsed thor-
oughly with clean water after leak checks have been com-
pleted.
NOTE: All gas piping must be arranged so that it does not interfere
with removal of any covers, inhibit service/maintenance, or re-
strict access between the unit and walls, or another unit.
− Prior to installation, all pipes should be de-burred and in-
ternally cleared of any scale, metal chips or other foreign
particles. Do Not install any exible connectors or unap-
proved gas ttings. Piping must be supported from the
oor, ceiling or walls only and must not be supported by
the unit.
− A suitable piping compound, approved for use with natural
gas, should be used. Any excess must be wiped off to pre-
vent clogging of components.
− To avoid unit damage when pressure testing gas piping,
isolate the unit from the gas supply piping. At no time
should the gas pressure applied to the unit exceed 20” W.C.
Leak test all external piping thoroughly using a soap and
water solution or suitable equivalent. The gas piping used
must meet all applicable codes.
− A sediment trap / drip leg must be installed on the gas sup-
ply piping.
− Installation of a union at the appliance gas line connection
is required for ease of service.
2.11.1 Gas Supply Specications
The gas supply input specications to the unit for Natural Gas are
as follows:
− The maximum static pressure to the unit must not exceed
20” W.C.
− The gas supply piping and pressure to the unit must be
of sufcient capacity to provide 3030 cfh for AR 3000 and
4040 cfh for AR 4000, while maintaining the recommended
minimum gas pressure at 8” W.C. for burners operating at
maximum capacity.
2.11.2 Manual Gas Shutoff Valve
A manual shut-off valve must be installed in the gas supply line
upstream of the boiler. Maximum allowable gas pressure to the
boiler is 20” W.C.

12
INSTALLATION
2.11.3 External Gas Supply Regulator
An external gas pressure regulator is required on the gas inlet pip-
ing under most conditions. Regulators must conform to the fol-
lowing specications:
− The external natural gas regulator must be capable of reg-
ulating
a) 100,000 - 3,000,000 BTU/HR for AR 3000
b) 100,000 - 4,000,000 BTU/HR for AR 4000
of natural gas while maintaining a recommended
minimum gas pressure of 8.0” W.C. to the unit.
− A regulator MUST be used when gas supply pressure will ex-
ceed 20” W.C.
The following are R’s recommendations for installation of gas
pressure regulator, unless superseded by state and local codes
and the regulator manufacturer’s specications:
− Horizontal installation of gas pressure regulators is recom-
mended unless stated otherwise by the regulator manu-
facturer. Consult the manufacturer for additional recom-
mendations and installation options.
− For all Array boilers, when installed horizontally the re-
quired distance between the gas pressure regulator and
the nearest pipe tting, elbow or valve is 10 feet.
− When pipe size reduction is required, use only bell reduc-
ers.
MASSACHUSETTS INSTALLATIONS ONLY
For Massachusetts installations, a mandatory external gas sup-
ply regulator must be installed. The gas supply regulator must be
properly vented to outdoors. Consult the local gas utility for de-
tailed requirements concerning venting of the supply gas regu-
lator.
The Commonwealth of Massachusettes prohibits the use of copper
tubing for the gas line.
NOTE: It is the responsibility of the customer to source and pur-
chase the appropriate gas regulator as described above.
2.11.4 Gas Type Conversion
The heating unit is factory preset for operating with natural gas.
This set-up can be changed using the conversion kits supplied by
the manufacturer, on demand.
9
DANGER: To prevent risks of personal injury and proper-
ty damage, this conversion shall only be performed by
a trained and certied installer in accordance with the
manufacturer’s instructions and all applicable codes
and requirements of the authority having jurisdiction.
If the information in these instructions is not followed exactly, or
the installation, adjustment, modication, operation or main-
tenance is carried out by an unqualied person, a re, explo-
sion or generation of large amounts of carbon monoxide may
result causing property damage, personal injury or loss of life.
Before carrying out electrical work, disconnect the appli-
ance from the power supply at the emergency shutoff switch
or by disengaging the heating system circuit breaker. Take
appropriate measures to prevent accidental reconnection.
The installer is responsible for the proper conversion of this
appliance. The conversion is not complete until the operation
of the converted appliance is checked as specied in these
instructions.
The gas-air ratio must always be set on the basis of a CO2or O2
reading taken at maximum nominal output and minimum nomi-
nal output using an electronic ue gas analyzer.
SWITCHING FROM NATURAL GAS TO LP
− Close the gas shutoff valve
− Disconnect the electric power supply from the boiler
9
WARNING: To avoid electrical shock, it is mandatory to discon-
nect the boiler from the power supply using a service discon-
nect external switch.
− Open the front panels
− Unscrew the swivel joint indicated in Fig. 12 to separate the
valve from the connection pipe with the fan
Swivel joint
LP Orifice
Fig. 12 Natural Gas to LP Gas Conversion
− Separating the two components, the hole where the gas
passes with its gasket can be accessed
− Place the provided metal orice (Fig. 12) between the two
gaskets (N° on orice: 9.5)
− Tighten the swivel joint
− Switch the main power supply to ON
− Use the 905PB inner display to enter in the parameter list
and change the parameter #95 (Gas Type) from “NG” to
“LPG”
− Reopen the gas shut-off valve
− Adjust the CO2parameter as explained in next chapter
− Afx the gas type label from the gas conversion kit to the
appliance.

13
INSTALLATION
2.11.5 Adjusting and setting CO2limits
− Insert a combustion analyzer probe into the test port
shown in Fig. 13
− Go to the Touchscreen and access the Module screen (as
described on ”4.3.4 Module Screen” pag. 26) relevant to the
module under analysis;
− Press “MODULE TEST” button;
− Press “HIGH POWER” button.
Wait 2 or 3 minutes to reach steady state conditions and record
the CO2value.
Test port of
the module
Fig. 13 Test Port for Combustion Analysis (available on each module)
To adjust the CO2 value at the maximum power turn the screw “A”
(rotate counter-clockwise to increase CO2) shown in Fig. 14, allen
type wrench is necessary for this adjustment.
Verify that the value of CO2is stable and is within the range indi-
cated in the following table (be careful to make small changes and
conrm that the value is stable before making additional adjust-
ment).
Press “LOW POWER”: the fan will run at the minimum speed.
Screw “B”
Screw “A”
Fig. 14 CO 2 Adjustment
To adjust the CO2 value at the minimum power turn the screw “B”
(rotate clockwise to increase CO2) shown in Fig. 14.
Verify that the value of CO2is stable and is within the range indi-
cated in the following table (be careful to make small changes and
conrm that the value is stable before making additional adjust-
ment).
Press “Reset” and the boiler return to the “stand by” mode.
Array Combustion Values
Gas Type Max. Fire CO2% Min. Fire CO2%
Natural Gas 8.5 - 9.5 8.5 - 9.5
LP Gas 10.3 - 10.7 10.3 - 10.7
2.12 AC electrical power wiring
External AC power connections are made to the unit inside the
electrical box, located on the front of the unit, inside the front
doors. Open the front doors and remove the panel mounted in
the upper part of the left front door of the unit as shown in Fig. 15.
Left Door
Cover Panel
Service
Display
Right Door
Cover Panel
Fig. 15 Front Doors Internal Layout
Loosen the screws of the cover and remove panel to access the
internal connections shown in Fig. 16.
Left Door
Electrical box
Right Door
Electrical box
Module Power
Switch
Module Power
Switch
Module Power
Switch
Module Power
Switch
Module Power
Switch
Module Power
Switch
Module Power
Switch
Module Power
Switch
Fig. 16 Front Doors Electrical box
7

14
INSTALLATION
All of the components in the Electrical box are mounted on a DIN
rail.
Main Switch
(backside view)
Terminal Blocks
Fig. 17 Left Front Door Electrical components
7
Terminal
Blocks
Fig. 18 Right Front Door Electrical components
7
9
WARNING: The main switch shown in Fig. 19 does not remove
power from the left door terminal blocks.
NOTE: All electrical conduit and hardware must be installed so that
it does not interfere with the removal of any unit covers, inhib-
it service/maintenance, or prevent access between the unit and
walls or another unit.
2.12.1 Electrical Power Requirements
The voltage conguration of Array AR 3000 and AR 4000 is as fol-
lows:
− 230VAC, Phase-Phase-Neutral, 60 Hz
Each unit must be connected to a dedicated electrical circuit.
NO OTHER DEVICES SHOULD BE ON THE SAME ELECTRICAL CIRCUIT AS
THE BOILER.
The Main Circuit two-pole switch is accessible on the front door
to quickly and safely disconnect electrical service (except the left
door terminal blocks).
Main Switch
(backside view)
Fig. 19 Main switch
Power Supply
connection
Fig. 20 Power supply connection
L1 L2
Ground
Neutral
Fig. 21 230VAC Power Supply connection

15
INSTALLATION
If an external electrical power source is used, the installed boil-
er must be electrically bonded to ground in accordance with the
requirements of the authority having jurisdiction. In the absence
of such requirements, the installation shall conform to National
Electrical Code (NEC), ANSI/NFPA 70 and/or the Canadian Electrical
Code (CEC) Part I, CSA C22.1 Electrical Code.
2.13 Field control wiring
Each unit is fully wired from the factory with an internal operat-
ing control system. No eld control wiring is required for normal
operation.
However, the control system used with all Array boilers does allow
for some additional control and monitoring features. Wiring con-
nections for these features are made on the Input / Output (I/O)
terminal strips located behind the removable cover on the inner
side of the front door of the unit, as shown in Fig. 22.
NOTE: Any electrical load connected to the terminal strip (external
pumps, air damper, alarm) must be powered through a relay, not
included in the boiler, to be provided and wired by the installer.
101 102 104 105 106 107 108 109 110 111 112 113 114 115103
ALARM PUMP DHW /
3-WAY DHW
3-WAY CH MAIN PUMP /
PUMP CH
Air Damper
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
CASCADE
LINK
AIR
DAMPER
Out
Door
Supply
Sensor
System
Sensor
BMS - RS232
RX TX GND
GND
DHW Tank
Sensor
Room
Thermostat
0-10 V
+
Fig. 22 I/O Terminal Strips
All eld wiring is installed from the rear of the panel by routing the
wires through one of the openings provided on the sides of the
cover panel.
Openings for wires
Fig. 23 Opening on the Cover Panel
2.13.1 Room Thermostat Connection (Enable/Disable)
The Room Thermostat (Enable/Disable) terminals (dry contacts)
come pre-wired closed (jumped) from the factory. For connecting
a room thermostat, the jumper must be removed and the ther-
mostat wires must be connected to terminals 11 and 12, as shown
in Fig. 22.
2.13.2 Air Damper
The Air Damper output comes disabled from the factory. For con-
necting an air damper, the Programmable Output 3 must be set to
10 and the damper wires must be connected to terminals 3 and 4,
as shown Fig. 22.
The Air Damper is connected to output J3-6 which is a Triac con-
trolled output.
This output need a minimum load of approx. 10VA to work cor-
rectly and the max load must be limited to 50VA at mains voltage.
Connection of an external relay to this output to be able to switch
a higher load is only possible when an additional resistor or load
is added to make sure the minimum load requirements are met.
2.13.3Outdoor Temperature Sensor
If outdoor temperature sensor is to be used, the outdoor probe
needs to be connected to terminals 5 and 6 as shown in Fig. 22.
The outdoor probe shall be installed on an outer wall, North or
North/East, away from windows, door, and ventilation grids.
Never install the probe in a position exposed to the sun.
The maximum length is 300’ (100 meters), if the cable length ex-
ceeds 32’ (10 meters) a shielded cable is required and shall be con-
nected to chassis ground.
NOTE: All sensors and low voltage wiring shall not be routed in
direct contact or near high voltage power.

16
INSTALLATION
2.14 Venting
Array boilers must be vented and supplied with combustion and
ventilation air as described in this section.
Installation must comply with local requirements and with the
National Fuel Gas Code ANSI Z223.1. Array boilers vent and air piping
can be installed through the roof or through a sidewall.
Any of the vent/air piping methods covered in this manual can be
used. Do not attempt to install the boilers using any other means.
Suitable, UL approved, positive pressure, watertight vent materials
MUST be used for safety and UL certication.
AR 3000 and AR 4000 boilers can use the following material for
venting:
Material Standard Maximum Flue
Temperature (°F)
Approved Man-
ufacturers
CPVC Schedule
40, 80
ANSI/ASTM
F441 194
Polypropylene ULC S636 230
Centrotherm Eco
Systems (InnoFlue
SW)
AL29-4C
stainless steel UL 1738
300+, limited only
by rating of seals
For specic venting components (terminals, ttings), contact the
respective vent manufacturer.
9
DANGER: It is extremely important to follow these venting in-
structions carefully. Failure to do so can cause severe personal
injury, death or substantial property damage.7
9
DANGER: Use of cellular core PVC (ASTM F891), cellular core CPVC
or Radel® (polyphenosulfone) in venting systems is prohibited.
9
WARNING: Do not connect this gas appliance with any other
appliance unless approved by manufacturer. Failure to comply
with this WARNING could result in the accumulation of carbon
monoxide gas which can cause severe personal injury or death
8” Flue Gas
Adapter
10” Flue Gas
connection
8” Air intake
Fig. 24 Combustion Air and Flue Gas Connections
9
DANGER: The condensate traps must be lled with water or
combustion gases will enter the room with a risk of an exces-
sive level of carbon monoxide.
7
− Vent connectors serving appliances vented by natural draft
shall not be connected to any portion of mechanical draft
systems operating under positive pressure.
− Ensure that the ue pipes and seals are not damaged.
− Use only primer and glue compounds approved for use
with the vent material used.
− Never install a barometric or a thermally controlled vent
damper with this boiler.
− Do not route the ue system piping through or inside an-
other duct that is used for exhausting air or other ue gas-
es.
− The condensate trap must be primed at all times. Failure
to do so may allow combustion gases to escape into boiler
room.
− The unit is to be used for either direct vent installation or
for installation using room air for combustion. When room
air is used, it is necessary to provide an adequate opening
for the fresh air intake.
− You must use any of the vent/air piping methods shown in
this manual.
− Be sure to locate the unit such that the vent and combus-
tion air piping can be routed through the building and
properly terminated.
− The boiler / vent installation must be in accordance with
Venting of Appliances, of the latest edition of the National
Fuel Gas Code, ANSI Z223.1/NFPA or applicable provisions of
the local, state and federal building codes.
− All vent pipes must be installed according to the vent man-
ufacturer’s instructions.
− The exhaust vent and the combustion air inlet lines must
be supported to prevent sagging per the vent manufactur-
er’s instructions.
− Do not mix components from different systems. The vent
system could fail, causing leakage of ue products into the
living space. Use only approved materials.
− Use of cellular core PVC and CPVC for venting system is not
allowed.
− The vent system shall be installed so as to prevent the ac-
cumulation of condensate.
− Consult local and state codes pertaining to special building
code and re department requirements. Adhere to nation-
al code requirements.
− Observe the listed maximum lengths of vent system, which
are boiler model dependent.
− To avoid moisture and frost build-up and to maintain
clearances to openings on adjacent structures, 45° and 90°
elbows or tees may be attached to the end of the vent ter-
mination pipe to direct exhaust plumes away from the ad-
jacent structure. The total allowable vent length, maximum
number of elbows and distance to air intake restrictions
must be adhered to.
− Due to the high efciency of the unit it may discharge what
looks like white smoke especially when the outside air
temperature is cold. This is due to the presence of water
vapor, normally present in the exhaust gases.

17
INSTALLATION
EXHAUST
BOILER
Fig. 25 All Combustion Air from Adjacent Indoor Spaces through
indoor Combustion Air Openings
EXHAUST
BOILER
Fig. 26 All Combustion Air from Outdoors - Through Ventilated Attic
EXHAUST
BOILER
Fig. 27 All Combustion Air From Outdoors - Inlet Air From Ventilat-
ed Crawl Space and Outlet Air to Ventilated Attic
EXHAUST
BOILER
AIR DUCT
AIR DUCT
Fig. 28 All Combustion Air from Outdoors through Horizontal Ducts
VENTING CONFIGURATIONS: The following gures show the acceptable piping installation for venting and combustion air.

18
INSTALLATION
BOILER
EXHAUST
Fig. 29 All Combustion Air from Outdoors through Single Combus-
tion Air Opening
BOILER
EXHAUST
Fig. 30 Sealed Combustion located on same side with Exhaust
(vertical)
EXHAUST
BOILER
Fig. 31 Sealed Combustion located on same side with Exhaust
(horizontal)
BOILER
EXHAUST
Fig. 32 Sealed Combustion located on side wall

19
INSTALLATION
BOILER
EXHAUST
Fig. 33 Exhaust located on side wall
− It is not recommended to terminate vent above any door
or window, condensate can freeze causing ice formations.
− Do not use chimney as a raceway if another boiler or re-
place is vented into or through chimney.
− Because the unit is capable of discharging low temperature
exhaust gases, the ue must be pitched back towards the
unit a minimum of 1/4” per foot to avoid any condensate
pooling and to allow for proper drainage.
− While there is a positive ue pressure during operation, the
combined pressure drop of vent and combustion air sys-
tems must not exceed the following equivalent length:
−
Model
PIPE SIZE - 8” PIPE SIZE - 10”
MAX. equiv.
(m)
MAX. equiv.
(ft)
MAX. equiv.
(m)
MAX. equiv.
(ft)
AR 3000 21 70 30 100
AR 4000 12 40 30 100
Fittings as well as pipe lengths must be calculated as part of the
equivalent length, according to the following table:
Model 45° ELBOW - 8” 45° ELBOW - 10”
equiv. (m) equiv. (ft) equiv. (m) equiv. (ft)
AR 3000 1.5 51.5 5
AR 4000 1.5 51.5 5
Model 90° ELBOW - 8” 90° ELBOW - 10”
equiv. (m) equiv. (ft) equiv. (m) equiv. (ft)
AR 3000 1.8 61.8 6
AR 4000 1.8 61.8 6
− For a natural draft installation the draft must not exceed -
0.25” W.C.
− These factors must be planned into the vent installation. If
the maximum allowable equivalent lengths of piping are ex-
ceeded, the unit will not operate properly or reliably.
− For Massachusetts installations, contact companies able to pro-
vide vent systems which conform to all applicable requirements
for installations within the Commonwealth of Massachusetts.
− For multiple boilers installation, common venting shall be sized
based on the data of Appendix M.
2.15 Combustion air
Air supply is a direct requirement of ANSI 223.1, NFPA-54, CSA B149.1
and local codes. These codes should be consulted before a perma-
nent design is determined.
Array boilers can take combustion air from the space in which are
installed, or the combustion air can be ducted directly to the unit.
Ventilation air must be provided in either case.
Material Standard
ABS ANSI/ASTM D1527
PVC Schedule 40 ANSI/ASTM D1785 or D2665
CPVC Schedule 40 ANSI/ASTM F441
Polypropylene ULC S636
Single wall galvanised steel 26 gauge
In cold climates it is essential to provide a motorized air inlet
damper to control the supply of combustion air and prevent nui-
sance condensation.
The combustion air must be free of:
− Permanent wave solutions;
− Chlorinated waxes/cleaners;
− Chlorine-based swimming pool chemicals;
− Calcium chloride
− Sodium chloride used for water softening;
− Refrigerant leaks;
− Paint or varnish removers;
− Hydrochloric acid/muriatic acid;
− Cements and glues;
− Antistatic fabric softeners used in clothes dryers;
− Chlorine-type bleaches, detergents, and cleaning solvents
found in household laundry rooms;
− Adhesives used to fasten building products and other sim-
ilar products.
To prevent contamination do not connect the combustion air inlet
and exhaust near:
− Dry cleaning/laundry areas and establishments;
− Swimming pools;
− Metal fabrication plants;
− Beauty shops;
− Refrigeration repair shops;
− Photo processing plants;
− Auto body shops;
− Plastic manufacturing plants;
− Furniture renishing areas and establishments;
− Remodeling areas;
− Garages with workshops
Whenever the environment contains these types of chemicals,
combustion air MUST be supplied from a clean area outdoors for the
protection and longevity of the equipment and warranty validation.
The more common methods of combustion air supply are outlined
in the following sections.

20
INSTALLATION
2.15.1 Combustion air from outside the building
Air supplied from outside the building must be provided through two
permanent openings. For each unit these two openings must have a
free area of not less than one square inch for each 4000 BTUs input of
the equipment or 750 square inches of free area. The free area must
take into account restrictions such as louvers and bird screens.
2.15.2 Combustion air from inside the building
When combustion air is provided from within the building, it must
be supplied through two permanent openings in an interior wall.
Each opening must have a free area of not less than one square inch
per 1000 BTUH of total input or 3000 square inches of free area. The
free area must take into account any restrictions, such as louvers.
2.15.3 Ducted combustion air
For ducted combustion air installations, the air ductwork must then be
attached directly to the air inlet connection on the sheet metal enclosure.
In a ducted combustion air application, the combustion air duct-
ing pressure losses must be taken into account when calculating
the total maximum allowable venting run.
For additional details, see “Appendix N - Exhaust terminals and Air
inlet Clearances”.