AER Benchmark BMK 750 User manual

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
OMM-0082_0J AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 1of 192
GF-130 Ph.: 800-526-0288 05/21/2014
BENCHMARK Series
Gas-Fired Boilers
USER MANUAL
Installation, Operation and Maintenance
Natural Gas & Propane
Modulating &
Condensing Hot Water Boiler
Models:
•BMK 750
•BMK 1000
Applicable to Serial Numbers:
•G-14-0752 and above
Latest Update: 05/21/2014

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
Page 2of 192 AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 OMM-0082_0J
05/21/2014 Ph.: 800-526-0288 GF-130
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 this
material.

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
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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 .................................................................................................................13
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 ...........................................................................................19
2.7 CONDENSATE DRAIN & PIPING .........................................................................................................20
2.8 GAS SUPPLY PIPING ........................................................................................................................... 22
2.8.1 Gas Supply Specifications ........................................................................................................... 22
2.8.2 Manual Gas Shutoff Valve ..........................................................................................................23
2.8.3 External Gas Supply Regulator.................................................................................................... 23
2.8.3.1 Massachusetts Installations Only.........................................................................................23
2.8.3.2 All Installations (Except Massachusetts)..............................................................................23
2.9 AC ELECTRICAL POWER WIRING........................................................................................................24
2.9.1 Electrical Power Requirements................................................................................................... 25
2.10 FIELD CONTROL WIRING..................................................................................................................26
2.10.1 OUTDOOR AIR IN Terminals......................................................................................................28
2.10.2 COMBUSTION AIR Terminal...................................................................................................... 29
2.10.3 O2SENSOR Terminals................................................................................................................29
2.10.4 SPARK SIGNAL Terminals .......................................................................................................... 29
2.10.5 ANALOG IN Terminals...............................................................................................................29
2.10.6 B.M.S. (PWM) IN Terminals ......................................................................................................29
2.10.7 SHIELD Terminals......................................................................................................................29
2.10.8 ANALOG OUT Terminals ...........................................................................................................30
2.10.9 RS-485 Comm Terminals........................................................................................................... 30
2.10.10 RS-232 Comm Terminals......................................................................................................... 30
2.10.11 VFD/Blower (0-10 & AGND)....................................................................................................30
2.10.12 Interlocks ................................................................................................................................30
2.10.12.1 REMOTE INTL’K Terminals................................................................................................30
2.10.12.2 DELAYED INTL’K Terminals (OUT & IN) ............................................................................ 30
2.10.13 FAULT RELAY (NC, COM, & NO) Terminals .............................................................................31
2.10.14 AUX RELAY CONTACTS (NC, COM, & NO) Terminals .............................................................. 31
2.11 FLUE GAS VENT INSTALLATION ....................................................................................................... 31
2.12 COMBUSTION AIR............................................................................................................................32
2.12.1 Combustion From Outside the Building ...................................................................................32

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2.12.2 Combustion Air from Inside the Building .................................................................................32
2.13 DUCTED COMBUSTION AIR ............................................................................................................. 33
2.14 BENCHMARK PUMP RELAY OPTION................................................................................................33
2.15 SEQUENCING ISOLATION VALVE INSTALLATION.............................................................................34
CHAPTER 3. OPERATION.........................................................................................37
3.1 INTRODUCTION .................................................................................................................................37
3.2 CONTROL PANEL DESCRIPTION......................................................................................................... 37
3.3 CONTROL PANEL MENUS ..................................................................................................................41
3.3.1 Menu Processing Procedure.......................................................................................................41
3.4 OPERATING MENU ............................................................................................................................ 43
3.5 SETUP MENU .....................................................................................................................................43
3.6 CONFIGURATION MENU.................................................................................................................... 44
3.7 TUNING MENU .................................................................................................................................. 46
3.8 COMBUSTION CAL MENU.................................................................................................................. 47
3.9 BST (Boiler Sequencing Technology ) Menu......................................................................................47
3.10 START SEQUENCE ............................................................................................................................50
3.11 START/STOP LEVELS ........................................................................................................................53
CHAPTER 4. INITIAL START-UP...............................................................................55
4.1 INITIAL START-UP REQUIREMENTS ...................................................................................................55
4.2 TOOLS AND INSTRUMENTATION FOR COMBUSTION CALIBRATION ................................................ 55
4.2.1 Required Tools & Instrumentation............................................................................................. 56
4.2.2 Installing Gas Supply Manometer............................................................................................... 56
4.2.3 Accessing the Analyzer Probe Port .............................................................................................57
4.3 NATURAL GAS COMBUSTION CALIBRATION ..................................................................................... 58
4.4 PROPANE COMBUSTION CALIBRATION.............................................................................................61
4.5 REASSEMBLY AFTER COMBUSTION CALIBRATION............................................................................64
4.6 OVER-TEMPERATURE LIMIT SWITCHES.............................................................................................65
4.6.1 Digital Alarm Switch Checks and Adjustments ........................................................................... 66
CHAPTER 5. MODE OF OPERATION........................................................................69
5.1 INTRODUCTION .................................................................................................................................69
5.2 INDOOR/OUTDOOR RESET MODE.....................................................................................................69
5.2.1 Reset Ratio..................................................................................................................................69
5.2.2 Building Reference Temperature................................................................................................69
5.2.3 Outdoor Air Temperature Sensor Installation............................................................................ 69
5.2.4 Indoor/Outdoor Startup .............................................................................................................70
5.3 CONSTANT SETPOINT MODE.............................................................................................................70
5.3.1 Setting the Setpoint....................................................................................................................70
5.4 REMOTE SETPOINT MODES...............................................................................................................71
5.4.1 Remote Setpoint Field Wiring.....................................................................................................72
5.4.2 Remote Setpoint Startup............................................................................................................ 72
5.5 DIRECT DRIVE MODES ....................................................................................................................... 72
5.5.1 Direct Drive Field Wiring............................................................................................................. 73
5.5.2 Direct Drive Startup ....................................................................................................................73
5.6 AERCO CONTROL SYSTEM (ACS)........................................................................................................73

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
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5.6.1 ACS External Field Wiring ........................................................................................................... 74
5.6.2 ACS Setup and Startup................................................................................................................ 74
5.7 COMBINATION CONTROL SYSTEM (CCS)...........................................................................................74
5.7.1 Combination Control System Field Wiring..................................................................................75
5.7.2 Combination Control System Setup and Startup........................................................................ 75
CHAPTER 6. SAFETY DEVICE TESTING..................................................................77
6.1 TESTING OF SAFETY DEVICES.............................................................................................................77
6.2 LOW GAS PRESSURE FAULT TEST ......................................................................................................78
6.3 HIGH GAS PRESSURE TEST................................................................................................................. 79
6.4 LOW WATER LEVEL FAULT TEST ........................................................................................................80
6.5 WATER TEMPERATURE FAULT TEST..................................................................................................81
6.6 INTERLOCK TESTS ..............................................................................................................................82
6.6.1 Remote Interlock Test ................................................................................................................ 82
6.6.2 Delayed Interlock Test ................................................................................................................82
6.7 FLAME FAULT TESTs ..........................................................................................................................83
6.8 AIR FLOW FAULT TESTS ..................................................................................................................... 84
6.8.1 Blower Proof Switch Test............................................................................................................84
6.8.2 Blocked Inlet Switch Test............................................................................................................84
6.9 SSOV PROOF OF CLOSURE SWITCH................................................................................................... 86
6.10 PURGE SWITCH OPEN DURING PURGE ........................................................................................... 87
6.11 IGNITION SWITCH OPEN DURING IGNITION ...................................................................................87
6.12 SAFETY PRESSURE RELIEF VALVE TEST ............................................................................................ 88
CHAPTER 7. MAINTENANCE....................................................................................89
7.1 MAINTENANCE SCHEDULE ................................................................................................................89
7.2 IGNITER-INJECTOR REPLACEMENT....................................................................................................90
7.3 FLAME DETECTOR REPLACEMENT..................................................................................................... 92
7.4 O2SENSOR REPLACEMENT ................................................................................................................93
7.5 COMBUSTION CALIBRATION .............................................................................................................93
7.6 SAFETY DEVICE TESTING....................................................................................................................93
7.7 BURNER ASSEMBLY INSPECTION.......................................................................................................93
7.8 CONDENSATE DRAIN TRAP MAINTENANCE ......................................................................................96
7.9 AIR FILTER CLEANING & REPLACEMENT............................................................................................98
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..................................99
CHAPTER 8. TROUBLESHOOTING GUIDE............................................................101
8.1 INTRODUCTION ...............................................................................................................................101
8.2 ADDITIONAL FAULTS WITHOUT SPECIFIC FAULT MESSAGES.......................................................... 113
CHAPTER 9. RS-232 COMMUNICATION................................................................117
9.1 INTRODUCTION ...............................................................................................................................117
9.1.1 Aquiring the PuTTY Application ................................................................................................117
9.1.2 Logging on to a Remote Machine Using PuTTY ........................................................................ 117
9.1.3 Running a Command on a Remote Machine Using PuTTY .......................................................118
9.2 RS-232 COMMUNICATION SETUP ...................................................................................................119

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9.3 MENU PROCESSING UTILIZING RS-232 COMMUNICATION ............................................................119
9.4 DATA LOGGING................................................................................................................................120
9.4.1 Fault Log.................................................................................................................................... 120
9.4.2 Operation Time Log ..................................................................................................................121
9.4.3 Sensor Log................................................................................................................................. 122
CHAPTER 10. BOILER SEQUENCING TECHNOLOGY........................................123
10.1 INTRODUCTION .............................................................................................................................123
10.2 AERCO BST Quick Start Chart ........................................................................................................ 124
10.3 BST Implementation Instruction ...................................................................................................125
10.3.1 Option 1 - Constant Setpoint with DIRECT Wired Header Sensor..........................................125
10.3.2 Option 2 - Constant Setpoint with MODBUS Wired Header Sensor ......................................126
10.3.3 Option 3 - Outdoor Reset with DIRECT WIRED Header Sensor AND DIRECT WIRED Outdoor
Sensor ................................................................................................................................................ 127
10.3.4 Option 4 - Outdoor Reset with MODBUS Header Sensor AND MODBUS Outdoor Sensor.... 129
10.3.5 Option 5 - Remote Setpoint with DIRECT WIRED Header Sensor AND 4-20ma Setpoint Drive
........................................................................................................................................................... 131
10.3.6 Option 6 - Remote Setpoint with DIRECT WIRED Header Sensor AND MODBUS Setpoint Drive
........................................................................................................................................................... 133
10.3.7 Option 7 - Remote Setpoint with MODBUS Header Sensor AND 4-20ma Setpoint Drive...... 134
10.3.8 Option 8 - Remote Setpoint with MODBUS Header Sensor AND MODBUS Setpoint Drive...136
APPENDIX A: BOILER MENU ITEM DESCRIPTIONS......................................................................139
APPENDIX B: STARTUP, STATUS & DISPLAY MESSAGES .............................................................145
APPENDIX C: SENSOR RESISTANCE/VOLTAGE CHART ................................................................ 149
APPENDIX D – INDOOR/OUTDOOR RESET RATIO CHARTS.........................................................151
APPENDIX E – BOILER DEFAULT SETTINGS .................................................................................155
APPENDIX F – DIMENSIONAL DRAWINGS .................................................................................. 157
APPENDIX G – PART LIST DRAWINGS .........................................................................................161
APPENDIX H – PIPING DRAWINGS..............................................................................................171
APPENDIX I – C-MORE WIRING DIAGRAMS................................................................................175
APPENDIX J – RECOMMENDED PERIODIC TESTING....................................................................179
APPENDIX K – C-MORE CONTROL PANEL VIEWS........................................................................ 181
APPENDIX L: RECOMMENDED SPARES...................................................................................... 183
APPENDIX M – ULTRA-LOW NOx CALIBRATION......................................................................... 185
LIMITED WARRANTY................................................................................................................... 189

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
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FOREWORD
The AERCO Benchmark (BMK) 750 and 1000 MBH Boilers are modulating and condensing
units. They are a true industry advancement 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
maximum turn down ratios for the BMK 1000 and BMK 750 are 20:1 and 15:1, respectively.
Both BMK models provide extremely high efficiencies and make them ideally suited for modern
low temperature, as well as, conventional heating systems.
The Benchmark Models BMK 750 and BMK 1000 operate within the following input and output
ranges:
Input Range (BTU/hr.)
Output Range (BTU/hr.)
Benchmark Model
Minimum
Maximum
Minimum
Maximum
BMK 750
50,000
750,000
47750
716,250
BMK 1000
50,000
1,000,000
48300
968,000
The output of each boiler model 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, the BMK 750 and BMK
1000 MBH 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 750 and BMK 1000 offer the
maximum venting flexibility with minimum installation space requirements. These Boilers are
Category II, III 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 PVC, CPVC, 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 both Benchmark
750 MBH and Benchmark 1000 MBH boilers.

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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
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 series boilers
BMS or BMS II AERCO Boiler Management Systems
BLDG (Bldg)
Building
BST AERCO on-board Boiler Management Technology
BTU British Thermal Unit. A unit of energy approximately equal to the heat
required to raise 1 pound of water 1° F.
CCP
Combustion Control Panel
C-More Controller
(or Control Box)
A control system developed by AERCO and currently used in all
Benchmark, Innovation and KC1000 Series product lines.
CO
Carbon Monoxide
COMM (Comm)
Communication
BTU British Thermal Unit. A unit of energy approximately equal to the heat
required to raise 1 pound of water 1° F.
Cal.
Calibration
CNTL
Control
DBB Double Block and Bleed. Used to define boiler gas trains containing 2 Safety Shutoff Valves (SSOVs) and a solenoid operated vent valve.
Also known as IRI gas trains (see below)
DIP
Dual In-Line Package
EMS
Energy Management System; often used interchangeably with BAS
FM
Factory Mutual. Used to define boiler gas trains.
GND
Ground
HDR
Header
Hex
Hexadecimal Number (0 – 9, A – F)
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

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Phrases, Abbreviations and Acronyms - Continued
Phrase, Abbreviation
or Acronym
Meaning
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
IRI Industrial Risk Insurers. A now discontinued code used to define gas
trains containing two SSOVs and a solenoid operated vent valve.
ISO
Isolated
LED
Light Emitting Diode
LN
Low NOx
MA (mA)
Milliampere (1 thousandth of an ampere)
MAX (Max)
Maximum
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
O2
Oxygen
O.D.
Outside Diameter
PMC Board A Primary Micro-Controller (PMC) board is contained in the C-More
Control Box used on all Benchmark units.
PPM
Parts Per Million
PTP
Point-to-Point (usually over RS-232 networks)
PWM
Pulse Width Modulation
REF (Ref)
Reference
RES.
Resistive
RS-232
(or EIA-232)
A standard for serial, full-duplex (FDX) transmission of data based on
the RS-232 Standard
RS-422
(or EIA-422)
A standard for serial, full-duplex (FDX) transmission of data based on
the RS-422 Standard
RS-485
(or EIA-485)
A standard for serial, half-duplex (HDX) transmission of data based on
the RS-485 Standard
RTN (Rtn)
Return
SETPT (Setpt)
Setpoint Temperature
SHLD (Shld)
Shield
SSOV
Safety Shut Off Valve
TEMP (Temp)
Temperature

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Phrases, Abbreviations and Acronyms –Continued
Phrase,
Abbreviation or
Acronym
Meaning
Terminating Resistor A resistor placed at each end of a daisy-chain or multi-drop network in
order to prevent reflection
s that may cause invalid data in the
communication
VDC
Volts, Direct Current
VFD
Vacuum Fluorescent Display, or Variable Frequency Drive
W
Watt
W.C.
Water Column
µA Micro amp (1 million
th
of an ampere)

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
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.
DO NOT USE MATCHES, CANDLES, FLAMES, OR OTHER SOURCES
OF IGNITION TO CHECK FOR GAS LEAKS.
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.
BEFORE ATTEMPTING TO PERFORM ANY MAINTENANCE ON THE
UNIT, SHUT OFF ALL GAS AND ELECTRICAL INPUTS TO THE UNIT.
THE EXHAUST VENT PIPE OF THE UNIT OPERATES UNDER A
POSITIVE PRESSURE AND THERE-FORE MUST BE COMPLETELY
SEALED TO PREVENT LEAKAGE OF COMBUSTION PRODUCTS INTO
LIVING SPACES.
WARNING
WARNING
WARNING
WARNING

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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.
A DOUBLE-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.
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.
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
WARNING
WARNING
CAUTION
CAUTION
MANUAL GAS SHUT-OFF VALVE
VALVE OPEN VALVE CLOSED

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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 of 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 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

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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.
(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 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 2 – INSTALLATION
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CHAPTER 2. INSTALLATION
2.1 INTRODUCTION
This Chapter provides the descriptions and procedures necessary to unpack, inspect and install
AERCO Benchmark Boiler Models BMK 750 and BMK 1000.
2.2 RECEIVING THE UNIT
Each Benchmark Boiler System is shipped as a single crated unit. The shipping weights for the
BMK 750 and BMK 1000 Models are approximately 1100 and 1200 pounds, respectively. 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, closely inspect the unit to make sure there is no evidence of damage not
indicated by the Tip-N-Tell indicator. Notify the freight carrier 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 (part no. 24060)
•1” Gas Supply Shutoff Valve
•Lifting Bar (with attaching hardware)
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.

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2.4 SITE PREPARATION
Ensure that the site selected for installation of the Benchmark Boiler includes:
•Access to AC Input Power at 120 VAC, Single-Phase, 60 Hz @ 20 Amps.
•Access to one of the following with the unit operating at maximum capacity:
oFor Benchmark 750 & 1000, a NATURAL GAS line at a minimum pressure of 4” W.C.
oFor Benchmark 750, a PROPANE gas line at a minimum pressure of 7” W.C.
oFor Benchmark 1000, a PROPANE gas line at a minimum pressure of 11” W.C.
2.4.1 Installation Clearances
Benchmark Models 750 and 1000 are packaged in enclosures 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
•Front : 24 inches
•Rear: 24 inches
•Top: 18 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.
Figure 2-1a: BMK 750 & 1000 Clearances
Housekeeping pad should not extend under the condensate assembly

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 2 – INSTALLATION
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Figure 2-1b: BMK 750 & 1000 Anchor Bolt Locations
KEEP THE UNIT AREA CLEAR AND FREE FROM ALL COMBUSTIBLE
MATERIALS AND FLAMMABLE VAPORS OR LIQUIDS.
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 inch to 6 inch housekeeping pad to ensure proper condensate
drainage (see NOTE below). If anchoring the unit, refer to the dimensional drawings in Figure 2-
1b for anchor locations.
NOTE
When using the AERCO Condensate Neutralizer Tank for proper
condensate drainage, the Neutralizer Tank must be stored in a pit, OR the
boiler and AERCO Condensate Trap must be elevated higher than 4”
above the floor. See Condensate Tank instructions in TID-0074 for details.
After unpacking and inspecting the boiler, remove the four (4) lag screws securing the boiler to
the shipping pallet. The boiler can be lifted and moved by inserting forklift tines in the front slots
provided in the base of the unit, or it can be lifted by attaching a lifting bar to the unit’s heat
exchanger. A lifting bar (59174), with attaching hardware, is supplied with each unit. When
shipped, this bar is attached to the rear of the unit as shown in Figure 2-2, View A. One (1)
WARNING
CAUTION

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lifting tab is provided at the top of the unit’s heat exchanger as shown. This tab is used to attach
the lifting bar to the unit as follows:
WHEN LIFTING OR MOVING THE BOILER:
•DO NOT ATTEMPT TO MANIPULATE THE BOILER USING THE
GAS TRAIN OR BLOWER
•WHEN USING THE LIFTING TAB AND BAR, ENSURE THERE IS
NO LOAD PLACED ON THE GAS TRAIN OR BLOWER
Attachment of Lifting Bar
1. Remove the lifting bar from its shipping location at the rear of the unit (Figure 2-2, View
A). Retain the attaching hardware consisting of two (2) hex head cap screws, hex nuts
and flat washers.
2. Remove the top shroud from the boiler by grasping the handle on the top of the unit and
lifting straight up. Locate the lifting tab at the top-rear of the heat exchanger.
3. Refer to Figure 2-2, View B and attach the lifting bar to the heat exchanger lifting tab
using the hardware removed in step 1. The upper end of the lifting bar containing the oval
cutout should be positioned over the top of the heat exchanger as shown.
4. Using proper rigging equipment, capable of supporting 1000 to 1200 lbs., lift the boiler
and position it on the housekeeping pad.
5. After the boiler is properly set on the pad, detach the lifting bar and replace the shroud on
the top of the unit.
6. Retain the lifting bar for possible reuse at the installation site.
Figure 2-2: Boiler Lifting Provisions
WARNING
LIFTING BAR IN
LIFTING
POSITION
LIFTING
BAR IN
SHIPPING
POSITION
LIFTING TAB
VIEW B - LIFTING POSITION
VIEW A - SHIPPING POSITION

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
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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.
2.5 SUPPLY AND RETURN PIPING
The Benchmark Boiler utilizes 3” 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. Refer to Appendix F, Drawing AP-A-891 for additional
dimensional data.
Figure2-3: Supply and Return Locations
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 psi to 160 psi. 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 of the floor to prevent injury in the event of a discharge.
The relief piping must be full size, without reduction. 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.
BOILER HOT
WATER OUTLET
1” NATURAL GAS
OR PROPANE
INLET
SECONDARY INLET
AIR INLET
PRIMARY INTLET
DRAIN VALVE
EXHAUST MANIFOLD

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CHAPTER 2 – INSTALLATION
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Figure2-4: Pressure Relief Valve Location
2.7 CONDENSATE DRAIN & PIPING
The Benchmark Boiler is designed to condense water vapor from the flue products. Therefore,
the installation must have provisions for suitable condensate drainage or collection.
The condensate drain port located on the exhaust manifold (Figure 2-5) must be connected to
the condensate trap (part no. 24060) which is packed separately within the unit’s shipping
container. The condensate trap inlet and outlet connections contain tapped 3/4” NPT ports.
Figure2-5: Condensate Drain Connection Location
A sample condensate trap installation is shown in Figure 2-6. However, the actual installation
details for the trap will vary depending on the available clearances, housekeeping pad height/
dimensions and other prevailing conditions at the site. The following general guidelines must be
observed to ensure proper condensate drainage:
•The condensate trap inlet (Figure 2-6) must be level with, or lower than the exhaust
manifold drain port.
•The base of the condensate trap must be supported to ensure that it is level (horizontal).
•The trap must be removable for routine maintenance. AERCO recommends that a union
be utilized between the exhaust manifold condensate drain port and the trap inlet port.
DRAIN VALVE
PRIMARY INTLET
EXHAUST
MANIFOLD
ANALYZER
PROBE PORT
CONDENSATE DRAIN
PARTIAL REAR VIEW
PRESSURE
RELIEF VALVE
3” HOT BOILER
WATER OUTLET
P&T GAUGE
COUPLING