AER Benchmark BMK 1500 User manual

Benchmark 1500 - 2000 Boilers
Installation, Operation & Maintenance Manual
OMM-0097_0E AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 1 of 182
GF-142 Ph.: 800-526-0288 10/01/2015
USER MANUAL
Installation, Operation and Maintenance
BENCHMARK
1500 and 2000
Gas-Fired Boilers
Natural Gas Modulating
& Condensing Hot Water
Boiler Models:
• BMK 1500
• BMK 2000
Applicable to Serial Numbers:
G-15-2700 and Above
Latest Update: 10/01/2015

Benchmark 1500 - 2000 Boilers
Installation, Operation & Maintenance Manual (IOMM)
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Technical Support
(Mon-Fri, 8am-5pm EST)
1-800-526-0288
www.aerco.com
DISCLAIMER
The information contained in this manual is subject to change without notice from AERCO
International, Inc. AERCO makes no warranty of any kind with respect to this material, including,
but not limited to, implied warranties of merchantability and fitness for a particular application.
AERCO International is not liable for errors appearing in this manual, nor for incidental or
consequential damages occurring in connection with the furnishing, performance, or use of these
materials.

Benchmark 1500 - 2000 Boilers
Installation, Operation & Maintenance Manual
OMM-0097_0E AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 3 of 182
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TABLE OF CONTENTS
FOREWORD 7
CHAPTER 1. SAFETY PRECAUTIONS .........................................................................................11
1.1 WARNINGS & CAUTIONS ................................................................................................................... 11
1.2 EMERGENCY SHUTDOWN ................................................................................................................. 12
1.3 PROLONGED SHUTDOWN ................................................................................................................. 12
CHAPTER 2. INSTALLATION ........................................................................................................15
2.1 INTRODUCTION ................................................................................................................................... 15
2.2 RECEIVING THE UNIT ......................................................................................................................... 15
2.3 UNPACKING ......................................................................................................................................... 15
2.4 SITE PREPARATION ........................................................................................................................... 16
2.4.1 Installation Clearances....................................................................................................................................16
2.4.2 Setting the Unit...............................................................................................................................................17
2.5 SUPPLY AND RETURN PIPING .......................................................................................................... 19
2.6 PRESSURE RELIEF VALVE INSTALLATION ..................................................................................... 20
2.7 CONDENSATE DRAIN & PIPING ........................................................................................................ 21
2.8 GAS SUPPLY PIPING .......................................................................................................................... 23
2.8.1 Gas Supply Specifications ...............................................................................................................................23
2.8.2 Manual Gas Shutoff Valve ..............................................................................................................................23
2.8.3 External Gas Supply Regulator........................................................................................................................24
2.9 AC ELECTRICAL POWER WIRING ..................................................................................................... 25
2.9.1 Electrical Power Requirements.......................................................................................................................26
2.10 FIELD CONTROL WIRING ................................................................................................................. 27
2.10.1 Outdoor Air In (OUT) & Air Sensor Common (COM) ....................................................................................28
2.10.2 AIR TEMP SENSOR Terminals........................................................................................................................29
2.10.3 O2SENSOR Terminals (O2+ & O2-) ...............................................................................................................29
2.10.4 SPARK SIGNAL Terminals ..............................................................................................................................29
2.10.5 ANALOG IN Terminals ...................................................................................................................................29
2.10.6 VALVE FEEDBACK Terminals .........................................................................................................................29
2.10.7 SHIELD Terminals (SHLD & SHLD) .................................................................................................................30
2.10.8 ANALOG OUT Terminals ...............................................................................................................................30
2.10.9 RS485 Comm (+, GND, & -) ...........................................................................................................................30
2.10.10 RS232 Comm (TxD & RxD) ..........................................................................................................................30
2.10.11 VFD/Blower (0-10 & AGND)........................................................................................................................30
2.10.12 Interlocks ....................................................................................................................................................30
2.10.13 Fault Relay (NC, COM, & NO)......................................................................................................................31
2.10.14 Auxiliary Relay Contacts (NC, COM, & NO).................................................................................................31
2.11 FLUE GAS VENT INSTALLATION ..................................................................................................... 31
2.12 COMBUSTION AIR ............................................................................................................................. 32
2.13 DUCTED COMBUSTION AIR ............................................................................................................. 32
2.14 SEQUENCING ISOLATION VALVE INSTALLATION ........................................................................ 33
CHAPTER 3. OPERATION ..............................................................................................................35
3.1 INTRODUCTION ................................................................................................................................... 35
3.2 CONTROL PANEL DESCRIPTION ...................................................................................................... 35
3.3 CONTROL PANEL MENUS .................................................................................................................. 39
3.3.1 Menu Processing Procedure...........................................................................................................................39
3.4 OPERATING MENU ............................................................................................................................. 41

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3.5 SETUP MENU ....................................................................................................................................... 42
3.6 CONFIGURATION MENU .................................................................................................................... 42
3.7 TUNING MENU ..................................................................................................................................... 45
3.8 COMBUSTION CAL MENU .................................................................................................................. 45
3.9 BST (BOILER SEQUENCING TECHNOLOGY) MENU ....................................................................... 46
3.10 START SEQUENCE ........................................................................................................................... 48
3.11 START/STOP LEVELS ....................................................................................................................... 52
CHAPTER 4. INITIAL START-UP..................................................................................................53
4.1 INITIAL START-UP REQUIREMENTS ................................................................................................. 53
4.2 TOOLS AND INSTRUMENTATION FOR COMBUSTION CALIBRATION .......................................... 53
4.2.1 Required Tools & Instrumentation .................................................................................................................54
4.2.2 Installing Gas Supply Manometer...................................................................................................................54
4.2.3 Accessing the Analyzer Probe Port .................................................................................................................55
4.3 NATURAL GAS COMBUSTION CALIBRATION .................................................................................. 56
4.3.1 BMK 1500 Natural Gas Combustion Calibration.............................................................................................56
4.3.2 BMK 2000 Natural Gas Combustion Calibration.............................................................................................60
4.4 REASSEMBLY ...................................................................................................................................... 62
4.5 OVER-TEMPERATURE LIMIT SWITCHES ......................................................................................... 63
4.5.1 Digital Alarm Switch Checks and Adjustments ...............................................................................................63
CHAPTER 5. MODE OF OPERATION...........................................................................................65
5.1 INTRODUCTION ................................................................................................................................... 65
5.2 INDOOR/OUTDOOR RESET MODE ................................................................................................... 65
5.2.1 Reset Ratio......................................................................................................................................................65
5.2.2 Building Reference Temperature....................................................................................................................65
5.2.3 Outdoor Air Temperature Sensor Installation ................................................................................................65
5.2.4 Indoor/Outdoor Startup .................................................................................................................................66
5.3 CONSTANT SETPOINT MODE ........................................................................................................... 66
5.3.1 Setting the Setpoint ........................................................................................................................................67
5.4 REMOTE SETPOINT MODES ............................................................................................................. 67
5.4.1 Remote Setpoint Field Wiring.........................................................................................................................68
5.4.2 Remote Setpoint Startup ................................................................................................................................68
5.5 DIRECT DRIVE MODES....................................................................................................................... 68
5.5.1 Direct Drive Field Wiring.................................................................................................................................69
5.5.2 Direct Drive Startup ........................................................................................................................................69
5.6 AERCO CONTROL SYSTEM (ACS) .................................................................................................... 70
5.6.1 ACS External Field Wiring................................................................................................................................70
5.6.2 ACS Setup and Startup....................................................................................................................................70
5.7 COMBINATION CONTROL SYSTEM (CCS) ....................................................................................... 71
5.7.1 Combination Control System Field Wiring......................................................................................................72
5.7.2 Combination Control System Setup and Startup............................................................................................72
CHAPTER 6. SAFETY DEVICE TESTING.....................................................................................73
6.1 TESTING OF SAFETY DEVICES ......................................................................................................... 73
6.2 LOW GAS PRESSURE TEST .............................................................................................................. 74
6.3 HIGH GAS PRESSURE TEST ............................................................................................................. 75
6.4 LOW WATER LEVEL FAULT TEST ..................................................................................................... 76
6.5 WATER TEMPERATURE FAULT TEST .............................................................................................. 76
6.6 INTERLOCK TESTS ............................................................................................................................. 78
6.6.1 Remote Interlock Test.....................................................................................................................................78
6.6.2 Delayed Interlock Test ....................................................................................................................................78

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6.7 FLAME FAULT TESTS ......................................................................................................................... 79
6.8 AIR FLOW FAULT TESTS .................................................................................................................... 81
6.8.1 Blower Proof Switch Test................................................................................................................................81
6.8.2 Blocked Inlet Switch Test ................................................................................................................................81
6.9 SSOV PROOF OF CLOSURE SWITCH ............................................................................................... 83
6.10 PURGE SWITCH OPEN DURING PURGE ........................................................................................ 84
6.11 IGNITION SWITCH OPEN DURING IGNITION ................................................................................. 85
6.12 SAFETY PRESSURE RELIEF VALVE TEST ..................................................................................... 86
CHAPTER 7. MAINTENANCE.........................................................................................................87
7.1 MAINTENANCE SCHEDULE ............................................................................................................... 87
7.2 IGNITER-INJECTOR ............................................................................................................................ 88
7.3 FLAME DETECTOR ............................................................................................................................. 90
7.4 O2 SENSOR 91
7.5 SAFETY DEVICE TESTING ................................................................................................................. 91
7.6 BURNER ASSEMBLY INSPECTION ................................................................................................... 92
7.7 CONDENSATE DRAIN TRAP .............................................................................................................. 95
7.8 AIR FILTER CLEANING & REPLACEMENT ........................................................................................ 96
7.9 WATER CUTOFF (LWCO) CAPACITOR INTEGRITY TEST ............................................................... 97
7.9.1 Low Water Cutoff (LWCO) - Capacitor Electrical Short Test ...........................................................................97
7.9.2 Low Water Cutoff (LWCO) - Standard C-More Test ........................................................................................99
7.10 SHUTTING THE BOILER DOWN FOR AN EXTENDED PERIOD OF TIME ..................................... 99
7.11 PLACING THE BOILER BACK IN SERVICE AFTER A PROLONGED SHUTDOWN ..................... 100
7.12 SPARK MONITOR (AC CURRENT TRANSDUCER) ....................................................................... 100
CHAPTER 8. TROUBLESHOOTING GUIDE............................................................................. 101
8.1 INTRODUCTION ................................................................................................................................. 101
8.2 ADDITIONAL FAULTS WITHOUT SPECIFIC FAULT MESSAGES .................................................. 113
CHAPTER 9. BOILER SEQUENCING TECHNOLOGY............................................................. 115
9.1 INTRODUCTION ................................................................................................................................. 115
9.1.1 Installation Notes..........................................................................................................................................116
9.2 AERCO BST QUICK START CHART ................................................................................................. 117
9.3 BST IMPLEMENTATION INSTRUCTION .......................................................................................... 118
9.3.1 Option 1 - Constant Setpoint with DIRECT Wired Header Sensor ................................................................118
9.3.2 Option 2 - Constant Setpoint with MODBUS Wired Header Sensor.............................................................119
9.3.3 Option 3 - Outdoor Reset with DIRECT WIRED Header Sensor AND DIRECT WIRED Outdoor Sensor .........120
9.3.4 Option 4 - Outdoor Reset with MODBUS Header Sensor AND MODBUS Outdoor Sensor...........................122
9.3.5 Option 5 - Remote Setpoint with DIRECT WIRED Header Sensor AND 4-20ma Setpoint Drive ...................124
9.3.6 Option 6 - Remote Setpoint with DIRECT WIRED Header Sensor AND MODBUS Setpoint Drive.................126
9.3.7 Option 7 - Remote Setpoint with MODBUS Header Sensor AND 4-20ma Setpoint Drive ............................127
9.3.8 Option 8 - Remote Setpoint with MODBUS Header Sensor AND MODBUS Setpoint Drive .........................129
APPENDIX A: BOILER MENU ITEM DESCRIPTIONS ............................................................. 131
TABLE A-1: OPERATING MENU ITEM DESCRIPTIONS ....................................................................... 131
TABLE A-2: SETUP MENU ITEM DESCRIPTIONS ................................................................................. 132
TABLE A-3: CONFIGURATION MENU ITEM DESCRIPTIONS .............................................................. 133
TABLE A-4: TUNING MENU ITEM DESCRIPTIONS ............................................................................... 136
TABLE A-5: COMBUSTION CALIBRATION MENU ITEM DESCRIPTIONS ........................................... 137
APPENDIX B: STARTUP, STATUS & DISPLAY MESSAGES .................................................. 139

Benchmark 1500 - 2000 Boilers
Installation, Operation & Maintenance Manual (IOMM)
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APPENDIX C: SENSOR RESISTANCE/VOLTAGE CHART...................................................... 143
APPENDIX D: RECOMMENDED PERIODIC TESTING ............................................................ 145
APPENDIX E: INDOOR/OUTDOOR RESET RATIO CHARTS ............................................... 147
APPENDIX F: DIMENSIONAL AND CLEARANCE DRAWINGS............................................. 151
APPENDIX G: PART LIST DRAWINGS ....................................................................................... 153
APPENDIX H: WIRING DIAGRAMS ............................................................................................. 165
APPENDIX I: PIPING DRAWINGS .............................................................................................. 173
APPENDIX J: C-MORE CONTROL PANEL VIEWS................................................................... 179
APPENDIX K: RECOMMENDED SPARES................................................................................... 181

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FOREWORD
The AERCO Benchmark (BMK) 1500 MBH (440 kW) and 2000 MBH (586 kW) 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 Benchmark's modulating capability relates energy input directly to
fluctuating system loads. The turn down ratios for these boilers is 20:1. These BMK models
provide extremely high efficiency operation and are ideally suited for modern low temperature,
as well as, conventional heating systems.
The Benchmark Model BMK 1500 and BMK 2000 boilers operate within the following input and
output ranges:
Benchmark
Model Input Range (BTU/hr.) Output Range (BTU/hr.)
Minimum
Maximum
Minimum
Maximum
BMK 1500 75,000 (22 kW) 1,500,000 (440 kW) 64,500 (18.9 kW) 1,395,000 (409 kW)
BMK 2000 100,000 (29.3 kW) 2,000,000 (586 kW) 86,000 (25.2 kW) 1,860,000 (545 kW)
The output of the boiler is a function of the unit’s firing rate (valve position) and return water
temperature.
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 BMK 1500 and BMK 2000 boilers offer
the maximum venting flexibility with minimum installation space requirements. These boilers are
Category II and IV, positive pressure appliances. Single and/or multiple breeched units are
capable of operation in the following vent configurations:
Conventional, Vertical
Conventional, Sidewall
Conventional, Direct Vent, Vertical
Sealed, Direct Vent, Horizontal
These boilers are capable of being vented utilizing Polypropylene and AL29-4C vent systems.
The Benchmark's advanced electronics are available in several selectable modes of operation
offering the most efficient operating methods and energy management system integration.
IMPORTANT
Unless otherwise specified, all descriptions and procedures provided in this
Installation, Operation & Maintenance Manual apply to the Benchmark
series of boiler.

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Phrases, Abbreviations and Acronyms
Phrase, Abbreviation
or Acronym Meaning
A (Amp) Ampere
ACS AERCO Control System, AERCO’s boiler management systems
ADDR Address
AGND Analog Ground
ALRM Alarm
ANSI American National Standards Institute,
ASME American Society of Mechanical Engineers
AUX Auxiliary
BAS Building Automation System, often used interchangeably with EMS
(see below)
Baud Rate
Symbol rate, or simply the number of distinct symbol changes
(signaling events) transmitted per second. It is not equal to bits per
second, unless each symbol is 1 bit long.
BMK (Benchmark) AERCO’s Benchmark series boilers
BMS or BMS II AERCO Boiler Management Systems
BLDG (Bldg) Building
BST AERCO on-board Boiler Sequencing Technology
BTU British Thermal Unit. A unit of energy approximately equal to the heat
required to raise 1 pound (0.45 kg) of water 1°F (0.55 °C)
BTU/HR BTUs per Hour (1 BTU/hr = 0.29 W)
CCP Combination Control Panel
CCS Combination Control System
C-More Controller
(or Control Box)
A control system developed by AERCO and currently used in all
Benchmark, Innovation and KC1000 Series product lines.
CFH Cubic Feet per Hour (1 CFH = 0.028 m
3
/hr)
CO Carbon Monoxide
COMM (Comm)
Communication
Cal.
Calibration
CNTL Control
CPU Central Processing Unit
DBB
Double Block and Bleed, a gas trains containing 2 Safety Shutoff
Valves (SSOVs) and a solenoid operated vent valve.
DIP Dual In-Line Package, a type of switch
ECU Electronic Control Unit (O
2
sensor)
EMS Energy Management System; often used interchangeably with BAS
FM
Factory Mutual. Used to define boiler gas trains.

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Phrase, Abbreviation
or Acronym
Meaning
GF-xxxx Gas Fired (an AERCO document numbering system)
GND Ground
HDR Header
Hex Hexadecimal Number (0 – 9, A – F)
HP Horse Power
HX Heat Exchanger
Hz Hertz (Cycles Per Second)
I.D. Inside Diameter
IGN Ignition
IGST Board Ignition/Stepper Board, contained in C-More Control Box
INTLK (INTL’K)
Interlock
I/O
Input/Output
I/O Box Input/Output (I/O) Box currently used on Benchmark, Innovation and
KC1000 Series products
IP Internet Protocol
ISO International Organization for Standardization
Lbs. Pounds (1 lb = 0.45 kg)
LED Light Emitting Diode
LN Low Nitrogen Oxide
MA (mA) Milliampere (1 thousand
th
of an ampere)
MAX (Max)
Maximum
MBH
1000 BTUs per Hour
MIN (Min) Minimum
Modbus® A serial, half-
duplex data transmission protocol developed by AEG
Modicon
NC (N.C.) Normally Closed
NO (N.O.) Normally Open
NOx Nitrogen Oxide
NPT National Pipe Thread
O
2
Oxygen
O.D. Outside Diameter
OMM & O&M
Operation and Maintenance Manual
OnAER
AERCO’s on-line remote monitoring system
PCB
Printed Circuit Board
PMC Board Primary Micro-Controller (PMC) board, contained in the C-More
P/N Part Number
POC
Proof of Closure
PPM Parts per Million

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Phrase, Abbreviation
or Acronym
Meaning
PSI Pounds per Square Inch (1 PSI = 6.89 kPa)
PTP Point-to-Point (usually over RS232 networks)
P&T Pressure and Temperature
ProtoNode Hardware interface between BAS and a boiler or water heater
PVC Poly Vinyl Chloride, a common synthetic plastic
PWM Pulse Width Modulation
REF (Ref) Reference
RES. Resistive
RS232
(or EIA-232)
A standard for serial, full-duplex (FDX) transmission of data based on
the RS232 Standard
RS422
(or EIA-422)
A standard for serial, full-duplex (FDX) transmission of data based on
the RS422 Standard
RS485
(or EIA-485)
A standard for serial, half-duplex (HDX) transmission of data based on
the RS485 Standard
RTN (Rtn) Return
SETPT (Setpt) Setpoint Temperature
SHLD (Shld) Shield
SPDT Single Pole Double Throw, a type of switch
SSOV Safety Shut Off Valve
TEMP (Temp) Temperature
Terminating Resistor
A resistor placed at each end of a daisy-chain or multi-drop network in
order to prevent reflections that may cause invalid
data in the
communication
Tip-N-Tell
A device that indicates if a package was tipped during shipping
UL
A business that tests and validates products
VAC
Volts, Alternating Current
VDC Volts, Direct Current
VFD Vacuum Fluorescent Display, also Variable Frequency Drive
W Watt
W.C. Water Column, a unit of pressure (1 W.C. = 249 Pa)
µA Micro amp (1 million
th
of an ampere)

Benchmark 1500 - 2000 Boilers
CHAPTER 1 – SAFETY PRECAUTIONS
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CHAPTER 1. SAFETY PRECAUTIONS
1.1 WARNINGS & CAUTIONS
Installers and operating personnel MUST, at all times, observe all safety regulations. The
following warnings and cautions are general and must be given the same attention as specific
precautions included in these instructions. In addition to all the requirements included in this
AERCO Instruction Manual, the installation of units MUST conform with local building codes, or,
in the absence of local codes, ANSI Z223.1 (National Fuel Gas Code Publication No. NFPA-54)
for gas-fired boilers and ANSI/NFPASB for LP gas-fired 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 installations are made.
See pages 13 and 14 for important information regarding installation of units within the
Commonwealth of Massachusetts.
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.
WARNING!
Do not use matches, candles, flames, or other sources of ignition to check
for gas leaks.
WARNING!
Fluids under pressure may cause injury to personnel or damage to
equipment when released. Be sure to shut off all incoming and outgoing
water shutoff valves. Carefully decrease all trapped pressures to zero
before performing maintenance.
WARNING!
Before attempting to perform any maintenance on the unit, shut off all gas
and electrical inputs to the unit.
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.
WARNING!
Electrical voltages up to 120 VAC may be used in this equipment.
Therefore the cover on the unit’s power box (located behind the front panel
door) must be installed at all times, except during maintenance and
servicing.

Benchmark 1500 - 2000 Boilers
CHAPTER 1 – SAFETY PRECAUTIONS
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WARNING!
A three-pole switch must be installed on the electrical supply line of the
unit. The switch must be installed in an easily accessible position to quickly
and safely disconnect electrical service. Do not affix switch to unit sheet
metal enclosures.
CAUTION
Many soaps used for gas pipe leak testing are corrosive to metals. The
piping must be rinsed thoroughly with clean water after leak checks have
been completed.
CAUTION
DO NOT use this boiler if any part has been under water. Call a qualified
service technician to inspect and replace any part that has been under
water.
1.2 EMERGENCY SHUTDOWN
If overheating occurs or the gas supply fails to shut off, close the manual gas shutoff valve
(Figure 1-1) located external to the unit.
NOTE
The Installer must identify and indicate the location of the
emergency shutdown manual gas valve to operating personnel.
Figure 1-1: Manual Gas Shutoff Valve
1.3 PROLONGED SHUTDOWN
After prolonged shutdown, it is recommended that the startup procedures in Chapter 4 and the
safety device test procedures in Chapter 6 of this manual be performed, to verify all system-
operating parameters. If there is an emergency, turn off the electrical power supply to the
AERCO boiler and close the manual gas valve located upstream the unit. The installer must
identify the emergency shut-off device.
VALVE OPEN VALVE CLOSED
MANUAL GAS SHUT-OFF VALVE

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CHAPTER 1 – SAFETY PRECAUTIONS
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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 fitter who is licensed
within the Commonwealth of Massachusetts.
• Prior to unit operation, the complete gas train and all connections 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 installation must conform to the
following requirements extracted from 248 CMR 5.08 (2):
(a) For all side wall horizontally vented gas fueled equipment installed 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 termination is less than
seven (7) feet above finished grade in the area of the venting, including but not limited to decks
and porches, the following requirements shall be satisfied:
1. INSTALLATION OF CARBON MONOXIDE DETECTORS. At the time of installation of
the side wall horizontal vented gas fueled equipment, the installing plumber or gasfitter shall
observe that a hard wired carbon monoxide detector with an alarm and battery back-up is
installed on the floor level where the gas equipment is to be installed. In addition, the
installing plumber or gasfitter 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 qualified 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 floor level.
b. 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 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 certified.
3. SIGNAGE. A metal or plastic identification 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 detectors and signage installed in accordance with the
provisions of 248 CMR 5.08(2)(a)1 through 4.

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CHAPTER 1 – SAFETY PRECAUTIONS
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(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
residential purposes.
(c) MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYSTEM
PROVIDED. When the manufacturer of Product Approved side wall horizontally 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 SYSTEM NOT
PROVIDED. When the manufacturer of a Product Approved side wall horizontally vented gas
fueled equipment does not provide the parts for venting the flue gases, but identifies "special
venting systems", the following requirements shall be satisfied by the manufacturer:
1. The referenced "special venting system" instructions shall be included with the appliance
or equipment installation instructions; 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 instructions, 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)]

Benchmark 1500 - 2000 Boilers
CHAPTER 2 – INSTALLATION
OMM-0097_0E AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 15 of 182
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CHAPTER 2. INSTALLATION
2.1 INTRODUCTION
This Chapter provides the descriptions and procedures necessary to unpack, inspect and install
the AERCO Benchmark Boiler Model BMK 1500 and BMK 2000.
2.2 RECEIVING THE UNIT
Each Benchmark Boiler System is shipped as a single crated unit. The shipping weight for these
BMK models is approximately 1800 pounds (817 kg). The unit must be moved with the proper
rigging equipment for safety and to avoid equipment damage. The unit should be completely
inspected 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
AERCO is not responsible for lost or damaged freight. Each unit
has a Tip-N-Tell indicator on the outside of the crate. This
indicates if the unit has been turned on its side during shipment. If
the Tip-N-Tell indicator is tripped, do not sign for the shipment.
Note the information on the carrier’s paperwork and request a
freight claim and inspection by a claims adjuster before
proceeding. Any other visual damage to the packaging materials
should also be made clear to the delivering carrier.
2.3 UNPACKING
Carefully unpack the unit taking care 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 not indicated by the Tip-N-Tell indicator. The freight carrier should be
notified 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 Valve
• Condensate Drain Trap (P/N 24441)
• 2” Natural Gas Supply Shutoff Valve
When optional accessories are ordered, they may be packed within the unit’s shipping
container, factory installed on the unit, or packed and shipped in a separate container. Any
standard or optional accessories shipped loose should be identified and stored in a safe place
until ready for installation or use.

Benchmark 1500 - 2000 Boilers
CHAPTER 2 – INSTALLATION
Page 16 of 182 AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 OMM-0097_0E
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2.4 SITE PREPARATION
Ensure that the site selected for installation of the Benchmark 1500/2000 Boiler includes:
• Access to AC Input Power at 120 VAC, Single-Phase, 60 Hz @ 20 Amps
• Access a Natural Gas line with a minimum pressure of 4 inches W.C. (996 Pa) with the unit
operating at maximum capacity:
2.4.1 Installation Clearances
The Benchmark Model 1500 and 2000 are packaged in an enclosure having identical exterior
dimensions. The unit must be installed with the prescribed clearances for service as shown in
Figure 2-1a. The minimum clearance dimensions, required by AERCO, are listed below.
However, if Local Building Codes require additional clearances, these codes shall supersede
AERCO’s requirements. Minimum acceptable clearances required are as follows:
• Sides: 24 inches (61 cm)
• Front: 24 inches (61 cm)
• Rear: 24 inches (61 cm)
• Top: 18 inches (45.7 cm)
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.
Figure 2-1a: Benchmark Boiler Model 1500/2000 Clearances
NOTE
Ensure that
condensate
assembly is not
located over the
housekeeping
pad.

Benchmark 1500 - 2000 Boilers
CHAPTER 2 – INSTALLATION
OMM-0097_0E AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 17 of 182
GF-142 Ph.: 800-526-0288 10/01/2015
WARNING!
Keep the unit area clear and free from all combustible materials and
flammable vapors or liquids.
CAUTION
While packaged in the shipping container, the unit must be moved by pallet
jack or forklift from the FRONT ONLY.
FOR MASSACHUSSETTS ONLY:
For Massachusetts installations, the unit must be installed by a plumber or
gas-fitter licensed within the Commonwealth of Massachusetts. In addition,
the installation must comply with all requirements specified in Chapter 1
(Safety Precautions), pages 11 and 12.
2.4.2 Setting the Unit
The unit must be installed on a 4 to 8 inch (10 to 20 cm) thick housekeeping pad to ensure
proper condensate drainage. If anchoring the unit, refer to Figure 2-1b for anchor locations.
Figure 2-1b: Benchmark 1500/2000 Anchor Bolt Locations
A total of 3 lifting lugs are provided at the top of the primary heat exchanger as shown in Figure
2-2. Remove the front top panel from the unit to provide access to the lifting tabs.
Remove the four (4) lag screws securing the unit to the shipping skid. Lift the unit off the
shipping skid and position it on the 4 to 8 inch (10 to 20 cm) concrete housekeeping pad
(required) in the desired location.
WARNING!
When lifting or moving the boiler, DO NOT attempt to manipulate
the boiler using the gas train or blower.

Benchmark 1500 - 2000 Boilers
CHAPTER 2 – INSTALLATION
Page 18 of 182 AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 OMM-0097_0E
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Figure 2-2: Boiler Lifting Provisions
In multiple unit installations, it is important to plan the position of each unit in advance. Sufficient
space for piping connections and future service/maintenance requirements must also be taken
into consideration. All piping must include ample provisions for expansion.
If installing a Combination Control Panel (CCP) system, it is important to identify the
Combination Mode Boilers in advance and place them in the proper physical location. Refer to
Chapter 5 for information on Combination Mode Boilers.
LIFTING LUGS
(3 POSITIONS)
2” (5.08 cm)
NATURAL GAS INLET

Benchmark 1500 - 2000 Boilers
CHAPTER 2 – INSTALLATION
OMM-0097_0E AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 19 of 182
GF-142 Ph.: 800-526-0288 10/01/2015
2.5 SUPPLY AND RETURN PIPING
The Benchmark Boiler utilizes 4” (10.16cm) 150# flanges for the water system supply and return
piping connections. The physical location of the supply and return piping connections are on the
rear of the unit as shown in Figure 2-3.
Figure 2-3: Supply and Return Locations
The optional dual inlet connections on the Benchmark 1500 and 2000 allow these units to be
configured with a separate cooler return temperature zone, rather than blending high and low
return temperature zones. Utilizing the dual return capability of these boilers can take further
advantage of the condensing capabilities of these models. When configured with a lower return
temperature zone or AERCO SmartPlates, thermal efficiency can improve by up to 10%.
If your unit includes the secondary inlet, pipe the warmer return water to the secondary (upper)
inlet and the cooler return water to the primary (lower) inlet. Contact your AERCO
representative for additional information.
2” (5.08cm) NATURAL
GAS INLET
BOILER HOT
WATER OUTLET
(SUPPLY)
EXHAUST MANIFOLD
CONDENSATE
DRAIN PORT
AIR INLET
DRAIN VALVE
OPTIONAL SECONDARY
WATER INLET
(WARMER WATER RETURN)
PRIMARY WATER INLET
(COOLER WATER RETURN)

Benchmark 1500 - 2000 Boilers
CHAPTER 2 – INSTALLATION
Page 20 of 182 AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 OMM-0097_0E
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2.6 PRESSURE RELIEF VALVE INSTALLATION
An ASME rated Pressure Relief Valve is supplied with each Benchmark Boiler. The pressure
rating for the relief valve must be specified on the sales order. Available pressure ratings range
from 30 to 160 psi (207 to 1103 kPa). The relief valve is installed on the hot water outlet of the
boiler as shown in Figure 2-4. A suitable pipe joint compound should be used on the threaded
connections. Any excess should be wiped off to avoid getting any joint compound into the valve
body. The relief valve must be piped to within 12 inches (30.5 cm) of the floor to prevent injury
in the event of a discharge. No valves, restrictions, or other blockages are allowed in the
discharge line. In multiple unit installations the discharge lines must NOT be manifolded
together. Each must be individually run to a suitable discharge location.
Figure 2-4: P&T Relief Valve Location
PRESSURE
RELIEF VALVE
4” HOT BOILER
WATER OUTLET
INSTALL
TRIDICATOR GAUGE
HERE
(P/N 123675-TAB)