AER AM 399B User manual

AM Series Boilers and Water Heaters
OMM-0100_0D AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 1of 154
GF-146 Ph.: 800-526-0288 03/28/16
USER MANUAL
AM Series
Natural Gas & Propane Modulating Condensing Boilers & Water Heaters
Applies to the following AM Series models:
Latest Update: 03/28/16
AM Boilers
•AM 399B
•AM 500B
•AM 750B
•AM 1000B
AM Water Heaters
Standard Models:
•AM 399W
•AM 500W
•AM 750W
•AM 1000W
Rapid Recovery
Option:
•AM 399RS
•AM 500RS
•AM 750RS
•
AM 1000RS

AM Series Boilers and Water Heaters
Page 2of 154 AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 OMM-0100_0D
03/28/16 Ph.: 800-526-0288 GF-146
TABLE OF CONTENTS
FOREWORD .......................................................................................................................7
CHAPTER 1: GENERAL INFORMATION..............................................................................9
1.1 WARNINGS & CAUTIONS............................................................................................................................9
1.2 EMERGENCY SHUTDOWN.......................................................................................................................12
CHAPTER 2: FUNCTIONAL OVERVIEW............................................................................13
2.1 INTRODUCTION.........................................................................................................................................13
2.1.1 AM Water Heaters and Boilers..............................................................................................................................13
2.1.2 AM Rapid Recovery (AMR) Skid Option.................................................................................................................13
2.2 INTENDED USE – BOILERS......................................................................................................................14
2.3 INTENDED USE – WATER HEATERS.......................................................................................................14
2.4 INTENDED USE – WATER HEATERS AND BOILERS WITH AMR OPTION...........................................14
2.5 AM SERIES FUNCTIONAL SCHEMATICS ................................................................................................15
2.5.1 AM 399 / 500 Functional Schematic......................................................................................................................15
2.5.2 AM 750 Functional Schematic...............................................................................................................................16
2.5.3 AM1000 Functional Schematic..............................................................................................................................17
2.5.4 AMR Functional Schematic....................................................................................................................................18
CHAPTER 3: INSTALLATION - SITE .................................................................................19
3.1 CHOOSING THE INSTALLATION LOCATION...........................................................................................19
3.2 BOILER AND WATER HEATER INSTALLATION LOCATION FACTORS.................................................20
3.3 SAFETY CONCERNS.................................................................................................................................21
3.4 CLOSET AND ALCOVE INSTALLATION ...................................................................................................21
3.5 CLEARANCES FOR INSTALLATION AND SERVICING ...........................................................................21
3.6 CLEARANCES TO COMBUSTIBLE MATERIAL........................................................................................22
3.7 VENT AND COMBUSTION AIR PIPING.....................................................................................................23
3.8 PREVENTION OF COMBUSTION AIR CONTAMINATION .......................................................................23
3.9 TRANSPORTING THE UNIT ......................................................................................................................23
3.10 UNPACKING AND TRANSPORTING.......................................................................................................23
3.10.1 Transporting a Standard AM Unit........................................................................................................................24
3.10.2 Transporting an AMR Water Heater....................................................................................................................26
3.11 AMR BUFFER TANK INSTALLATION......................................................................................................27
3.11.1 AMR Buffer Tank Installation Kits........................................................................................................................27
3.12 AMR BUFFER TANK COMPONENTS......................................................................................................28
3.13 BUFFER TANK INSTALLATION OVERVIEW ..........................................................................................28
3.14 REMOVING THE AMR BRACING PLATE................................................................................................29
3.15 AMR 80-GALLON BUFFER TANK INSTALLATION.................................................................................29
3.16 AMR 119-GALLON BUFFER TANK INSTALLATION..............................................................................31
3.17 AM SERIES SUPPLY AND RETURN PIPING DIMENSIONS..................................................................33
3.17.1 Standard AM Supply and Return Piping Dimensions...........................................................................................33
3.17.2 AMR Supply and Return Piping Dimensions........................................................................................................34
CHAPTER 4: INSTALLATION - PIPING .............................................................................35
4.1 WATER INLET AND OUTLET PIPING .......................................................................................................35
4.2 WATER QUALITY .......................................................................................................................................35
4.3 SYSTEM PIPING METHODS - BOILERS...................................................................................................35
4.4 FREEZE PROTECTION..............................................................................................................................36
4.5 FLOOR RADIANT HEATING SYSTEMS - BOILERS.................................................................................36
4.6 PIPING COMPONENTS - BOILERS...........................................................................................................36
4.7 PIPING COMPONENTS – WATER HEATERS...........................................................................................37
4.8 SAFETY RELIEF VALVE ............................................................................................................................38

AM Series Boilers and Water Heaters
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4.9 LOW WATER CUTOFF (LWCO).................................................................................................................39
4.10 EXPANSION TANK AND MAKEUP WATER............................................................................................40
4.11 CIRCULATOR HEATING PUMP...............................................................................................................40
4.12 DOMESTIC HOT WATER SYSTEM PIPING WITH DIRECT WATER HEATER – WATER HEATERS..42
4.13 SCALDING – WATER HEATERS.............................................................................................................43
4.14 CONDENSATE DISPOSAL.......................................................................................................................45
CHAPTER 5: INSTALLATION - ELECTRICAL....................................................................47
5.1 ELECTRICAL CONNECTIONS – BOILERS AND WATER HEATERS......................................................47
5.1.1 Power Supply Cable Connection - Boilers and Water Heaters..............................................................................47
5.1.2 ConnectingUnitsinCascade - Boilers and Water Heaters ..................................................................................48
5.1.3 0-10 VDC Input Connections - Boilers and Water Heaters....................................................................................48
5.1.4 MODBUS Interface Connections – Boilers and Water Heaters .............................................................................49
5.2 ELECTRICAL CONNECTIONS – BOILERS ONLY....................................................................................50
5.2.1 Enable/Disable - Boilers.........................................................................................................................................50
5.2.2 Installing the Outdoor Temperature Sensor - Boilers............................................................................................50
5.2.3 Indirect Water Heater Connection - Boilers..........................................................................................................51
5.2.4 Indirect Water Heater Priority Selection - Boilers.................................................................................................52
5.3 ELECTRICAL CONNECTIONS – WATER HEATERS ONLY.....................................................................52
5.3.1 Storage Tank Connection - Water Heaters............................................................................................................52
5.4 AMR RAPID RECOVERY OPTION WIRING..............................................................................................52
CHAPTER 6: INSTALLATION – VENTING AND COMBUSTION AIR PIPING......................55
6.1 COMBUSTION AIR CONTAMINATION PREVENTION .............................................................................55
6.2 GENERAL VENTING AND AIR PIPING SYSTEMS...................................................................................56
6.3 MIN/MAX ALLOWABLE COMBUSTION AIR AND VENT PIPING LENGTHS...........................................58
6.4 GENERAL VENTING AND COMBUSTION AIR PIPING INSTALLATION.................................................58
6.5 SPECIFIC VENT INSTALLATIONS ............................................................................................................58
6.5.1 Installations Requiring High Temperature Venting...............................................................................................59
6.5.2 Sealing of PVC, CPVC or ABS..................................................................................................................................60
6.5.3 PVC/CPVC Vent Piping Materials...........................................................................................................................60
6.5.4 Air Intake and Vent Starter Pieces.........................................................................................................................61
6.5.5 Single Pipe Venting (Room Air Combustion) .........................................................................................................62
6.5.6 Determining Vent Termination Location...............................................................................................................63
6.5.7 Sidewall Termination - Two pipes .........................................................................................................................64
6.5.8 Combustion Air and Ventilation Openings............................................................................................................65
6.5.9 Two Permanent Openings Method.......................................................................................................................65
6.5.10 One Permanent Opening Method.......................................................................................................................65
6.5.11 Installing Vent and Air Piping into Sidewall.........................................................................................................65
6.5.12 Sidewall Termination and Fittings.......................................................................................................................66
6.5.13 Multiple Vent and Air Terminations....................................................................................................................66
6.5.14 Sidewall Termination – Concentric Vent.............................................................................................................67
6.5.15 Sidewall Termination Installation........................................................................................................................68
6.5.16 Multi-venting Sidewall Terminations ..................................................................................................................69
6.5.17 Determining Location of Vertical Termination....................................................................................................70
6.5.18 Vertical Vent and Air Roof Termination Preparation ..........................................................................................71
6.5.19 Installing Vertical Vent and Air Roof Terminations .............................................................................................71
6.5.20 InstallingMultipleVentand AirVerticalTerminations .....................................................................................72
6.5.21 Vertical Termination – Concentric Vent..............................................................................................................73
6.5.22 Determining Location of Vertical Concentric Vent Termination.........................................................................73
6.5.23 Multi-VentingVerticalTerminations ..................................................................................................................73
CHAPTER 7: INSTALLATION – NATURAL GAS ................................................................75
7.1 GAS SUPPLY PIPING.................................................................................................................................75

AM Series Boilers and Water Heaters
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7.2 CONNECTION OF GAS SUPPLY PIPING .................................................................................................75
7.3 NATURAL GAS PIPE SIZING.....................................................................................................................77
7.4 NATURAL GAS SUPPLY PRESSURE REQUIREMENTS.........................................................................77
7.5 PROPANE GAS PIPE SIZING....................................................................................................................77
7.6 PROPANE GAS SUPPLY PRESSURE REQUIREMENTS........................................................................77
7.7 CHECKING AND ADJUSTING THE UNIT INLET GAS SUPPLY PRESSURE..........................................78
7.8 HIGH ALTITUDE OPERATION...................................................................................................................78
7.9 CONVERSION FROM NATURAL GAS TO PROPANE GAS.....................................................................78
7.9.1 Gas Conversion Kit.................................................................................................................................................78
7.9.2 Gas Conversion Instructions..................................................................................................................................78
CHAPTER 8: UNIT START-UP...........................................................................................83
8.1 INITIAL START-UP REQUIREMENTS .......................................................................................................83
8.1.1 Filling the Condensate Neutralizer........................................................................................................................83
8.1.2 Filling the Heating System.....................................................................................................................................83
8.2 GENERAL WARNINGS CONCERNING THE GAS SUPPLY.....................................................................84
8.2.1 Confirming the Unit’s Gas Type.............................................................................................................................85
8.2.2 Gas Type Conversion .............................................................................................................................................85
8.3 IDENTIFICATION OF CONTROLS.............................................................................................................86
8.4 BOILER STARTUP PROCEDURE..............................................................................................................86
8.5 WATER HEATER STARTUP PROCEDURE..............................................................................................87
8.6 GAS SUPPLY PRESSURE TEST...............................................................................................................88
8.7 COMBUSTION CALIBRATION...................................................................................................................90
8.8 LOST IGNITION PROCEDURE......................................................................................................................91
8.9 MINIMUM WATER FLOW...........................................................................................................................91
8.10 HEATING SYSTEM PRESSURE TEST....................................................................................................92
CHAPTER 9: OPERATION.................................................................................................93
9.1 GENERAL OPERATION .............................................................................................................................93
9.2 FREEZE PROTECTION..............................................................................................................................94
9.3 DISPLAY ENERGY SAVING MODE...........................................................................................................94
9.4 CONTROL PANEL DISPLAY......................................................................................................................94
9.5 STARTUP PROCEDURE - BOILERS.........................................................................................................95
9.6 BOILER SUMMER MODE...........................................................................................................................95
9.7 ADJUSTING THE DOMESTIC HOT WATER TEMPERATURE - BOILERS..............................................96
9.8 HEATING SYSTEM TEMPERATURE ADJUSTMENT - BOILERS............................................................96
9.9 HEATING SYSTEM TYPE SELECTION - BOILERS..................................................................................96
9.10 OUTDOOR RESET ADJUSTMENT - BOILERS.......................................................................................96
9.10.1 Outdoor Reset: Setting Parameters ....................................................................................................................97
9.10.2 Outdoor Reset Activation....................................................................................................................................97
9.11 BOILER DELAYS, ALARMS AND PROTECTIVE ACTIONS ...................................................................98
9.12 BOILER CIRCULATOR PUMP PROTECTION.........................................................................................98
9.13 STARTUP PROCEDURE - WATER HEATERS .......................................................................................98
9.14 ADJUSTING THE STORAGE TANK TEMPERATURE (WATER HEATERS)..........................................99
9.15 USER MENU...........................................................................................................................................100
9.16 INSTALLER MENU .................................................................................................................................101
9.17 FACTORY MENU....................................................................................................................................103
9.18 DIAGNOSTICS – DISPLAY MESSAGES...............................................................................................106
9.19 DIAGNOSTICS – LOCKOUT (LOC) ERRORS.......................................................................................106
9.20 DIAGNOSTICS – BLOCKING (ERR) ERRORS......................................................................................108
9.21 BLOCKED FLUE PRESSURE SWITCH.................................................................................................110
9.22 UNIT SHUT-DOWN.................................................................................................................................111

AM Series Boilers and Water Heaters
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CHAPTER 10: MAINTENANCE..........................................................................................113
10.1 CHECKING FOR GAS LEAKS................................................................................................................114
10.2 FLUE AND AIR INLET PIPING INSPECTION........................................................................................114
10.3 SYSTEM PIPING, PRESSURE, AND EXPANSION TANK INSPECTION.............................................114
10.4 IGNITION AND FLAME SENSOR INSPECTION....................................................................................114
10.5 WIRING AND CONNECTIONS INSPECTION........................................................................................114
10.6 PERFORMANCE VERIFICATION INSPECTION...................................................................................114
10.7 FLAME INSPECTION..............................................................................................................................114
10.8 FLAME SIGNAL INSPECTION ...............................................................................................................115
10.9 RELIEF VALVE INSPECTION ................................................................................................................115
10.10 UNIT VICINITY INSPECTION...............................................................................................................115
10.11 PRESSURE GAUGE INSPECTION......................................................................................................115
10.12 CONDENSATE DRAIN SYSTEM INSPECTION ..................................................................................116
10.13 LOW WATER CUTOFF TEST...............................................................................................................116
10.14 REMOVING THE UNIT COVERS.........................................................................................................117
10.15 CLEANING THE BURNER AND PRIMARY HEAT EXCHANGER (FLUE/GAS SIDE) ........................118
10.16 INSPECTING AND REPLACING THE HEAT EXCHANGER THERMAL INSULATION.......................122
10.17 INSPECTING AND REPLACING THE BURNER THERMAL INSULATION.........................................123
10.18 CHECKING FOR GAS LEAKS AFTER REASSEMBLY........................................................................125
10.19 IGNITION AND FLAME DETECTION SENSOR ELECTRODE POSITIONING...................................126
10.20 AIR FILTER CLEANING........................................................................................................................127
10.21 CONDENSATE TRAP AND NEUTRALIZING RESERVOIR MAINTENANCE.....................................128
10.22 CONTROL BOARD REPLACEMENT...................................................................................................130
10.23 DRAINING THE WATER FROM THE UNIT .........................................................................................131
10.24 WATER AND FLUE TEMPERATURE SENSOR ..................................................................................132
10.25 OUTDOOR TEMPERATURE SENSOR (BOILERS ONLY)..................................................................132
10.26 AM RAPID RECOVERY (AMR) OPTION MAINTENANCE ..................................................................133
10.26.1 Components and Piping ..................................................................................................................................133
10.26.2 Buffer Tank Anode Rods..................................................................................................................................133
10.27 MAINTENANCE KITS PART LISTS......................................................................................................134
10.27.1 Wiring Diagram................................................................................................................................................135
CHAPTER 11: TECHNICAL DATA.....................................................................................137
CHAPTER 12: SPARE PARTS DRAWINGS & LISTS..........................................................139
12.1 AM 399/500 SPARE PARTS DRAWINGS..............................................................................................139
12.2 AM 399/500 SPARE PARTS LIST ..........................................................................................................142
12.3 AM 750/1000 SPARE PARTS DRAWINGS............................................................................................145
12.4 AM 750/1000 SPARE PARTS LIST ........................................................................................................148
12.5 AMR OPTION SPARE PARTS DRAWING.............................................................................................151
12.6 AM RAPID RECOVERY (AMR) OPTION SPARE PARTS LIST.............................................................152
APPENDIX A: CONTROL PANEL OPERATION CHART .....................................................153

AM Series Boilers and Water Heaters
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AM Series Boilers and Water Heaters
FORWARD
OMM-0100_0D AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 7of 154
GF-146 Ph.: 800-526-0288 03/28/16
FOREWORD
The Advanced Modular (AM) Series represents the latest in high efficiency, condensing boiler
and water heater technology. The AM Series has a unique modular design that provides
exceptional reliability, serviceability, and fuel savings from 399 to 1000 MBTU. Each unit is
comprised of between two and four independent thermal modules firing up to 250 MBTU each at
5:1 individual turndown. This allows for superior temperature control and low-cycling operation.
This unique design provides the multiple boiler redundancy required in a boiler plant, but in a
single unit installation with one set of water connections, one gas connection, and one vent
connection. When needed, multiple units are easily co-located to provide a boiler plant with
the highest efficiency, turndown, and redundancy in the smallest footprint. Multiple units are
sequenced through the AERCO AM Cascade Manager. Each unit is equipped for Modbus
communication to a BAS. High efficiencies and low vent temperatures mean the unit can be
vented in PVC, CPVC, Polypropylene, and AL29-4C vent materials. The front-access design also
means the unit is very simple to maintain and service.
Features:
• High Efficiency Condensing Boiler/Water Heater
• Natural Gas or Propane
• Superior Turndown 8:1 to 20:1 (depending on unit)
• Low NOx Emission <20ppm
• Direct or Conventional Vent with PVC, CPVC, Polypropylene, or AL29-4C materials
• Concentric Vent Capability
• Common Vent Capability
• Side wall common venting with no additional check valve
• Small, Doorway-Size Footprint
• Superior Reliability
• Minimal Maintenance
• Easy Front Access for Serviceability
• Zero Side Clearance
• Supports Integration to BAS System
• Modbus Communication Standard
• Integrated isolation valves, flow meters, and condensate neutralizer

AM Series Boilers and Water Heaters
FORWARD
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AM Series Boilers and Water Heaters
CHAPTER 1: GENERAL INFORMATION
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CHAPTER 1: GENERAL INFORMATION
1.1 Warnings & Cautions
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.
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!
Failure to comply with provisions, warnings, and cautions provided in this manual can lead to
extensive property damage and/or personal injury or death.
In the event of a breakdown and/or malfunction of the boiler, turn off the unit and do not make
any attempt to repair it. The boiler must be serviced exclusively by a Qualified installer using
original spare parts. Failure to comply with this requirement may compromise the safety of the
unit.
WARNING!
Installer: Read all instructions including this manual, before installing. Perform steps in the
order given.
User: The installation and maintenance sections of this manual are for use only by a qualified
heating installer. Refer to Chapter 9: Operation for user information.
Installation and Alterations: Only a Qualified installer must carry out the installation and
calibration of the boiler. Never modify the boiler or its components in any way.
Overheating: Should overheating occur or the gas supply fail; to shut off, do not turn off or
disconnect electrical supply to circulator. Instead, turn off the manual gas shut-off valve external
to the appliance.
Water Contamination:Do not use this appliance if any part has been under water.
Immediately call a licensed authorized technician to inspect the appliance and to replace any
part of the control system and any gas control, which has been under water.
Ensure the boiler and its controls are protected from dripping or spraying water during normal
operation or service.
Spare Parts: Only use the boiler with the accessories and spares listed in this manual. Failure
to do so can cause equipment damage or dangerous conditions.

AM Series Boilers and Water Heaters
CHAPTER 1: GENERAL INFORMATION
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NOTE
When calling or writing about the boiler, have the unit model and
serial number as seen on the unit rating plate.
CAUTION!
Do not use petroleum-based cleaning or sealing compounds in the
boiler system. Gaskets and seals in the system may be damaged.
This can result in substantial property damage.
The manufacturer declines all liability, contractual or otherwise
(warranty included), for any damage to people, animals property
or this same appliance, caused by:
•Incorrect installation or failure to comply with this or any
other instruction provided by the manufacturer;
•Failure to comply with the applicable local and/or national
regulations in force.
•Incorrect use of this appliance.
•Inadequate or incorrect service
•Inadequate or incorrect maintenance.

AM Series Boilers and Water Heaters
CHAPTER 1: GENERAL INFORMATION
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OFF.
OFF.

AM Series Boilers and Water Heaters
CHAPTER 1: GENERAL INFORMATION
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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
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 requirements in 248 CMR
5.08 (2).
•Must be installed according to all local codes.

AM Series Boilers and Water Heaters
CHAPTER 2: FUNCTIONAL OVERVIEW
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CHAPTER 2: FUNCTIONAL OVERVIEW
2.1 INTRODUCTION
2.1.1 AM Water Heaters and Boilers
Figure 2-1 shows the exterior appearance of the AM Series of boilers and water heaters. The
AM Series comes in four functionally sized models; the 399, 500, 750, and 1000. Boilers are
appended with a B (i.e. AM 1000B), and water heaters with a W (i.e. AM 1000W).
Figure 2-1: AM Boiler or Water Heater (AM 399/500 Left, AM 750/ AM 1000 Right)
2.1.2 AM Rapid Recovery (AMR) Skid Option
Figure 2-2 shows the AMR option, comprised of an AM water heater, thermal buffer tank, low
water cutoff (LWCO), recirculation loop piping, and recirculation loop pump.
Figure 2-2: AM Water Heater with Rapid Recovery Option (AM 1000RS Shown)
AM SERIES
WATER HEATER
(AM750 OR AM1000)
RECIRCULATION
LOOP PUMP
RECIRCULATION
LOOP PIPING
HOT WATER OULET
AM 750 / 1000
AM 399 / AM 500
CONTROL
PANEL
THERMAL
BUFFER TANK
COLD WATER INLET
OPTIONAL SR300
SCALE REDUCTION
SYSTEM
SAFETY RELIEF VALVE

AM Series Boilers and Water Heaters
CHAPTER 2: FUNCTIONAL OVERVIEW
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2.2 Intended Use – Boilers
The gas-fired condensing AM Series boilers are designed to be used in central heating
systems. Any other use is prohibited.
Heat is always guaranteed for the production of domestic hot water since it is given priority
over space heating demands. Follow the specific procedure in Section 9.7 for boiler
adjustment for domestic hot water temperature. This boiler can be connected to an indirect
storage tank for the production of domestic hot water (Section 4.10).
This unit can be installed with a direct venting system or with a one pipe vent system and
draw combustion air from the room.
The quality of the system water is very important. Poor water quality can damage
heating systems and boilers due to scale formation and corrosion.
A heating system can be configured to function at a temperature range of between 68°F (20°C)
and 180°F (82°C).
The AM Series boiler can be connected to a room On/Off control (Section 5.2.1).
An outdoor air temperature sensor must also be connected to the boiler for an outdoor reset
supply temperature control for maximum fuel efficiency and comfort. For further information on
the outdoor-air reset, refer to Section 9.10.
2.3 Intended Use – Water Heaters
The gas fired condensing AM Series water heaters are designed to be used for domestic hot
water production. Any other use is prohibited.
The water heaters must be connected to a storage tank for the production of domestic hot
water. When connecting the water heater to the storage water heater, the installer must
consider the head loss of the water heater (see figure 4-4), the head loss of the piping system
and the head loss of the storage water heater to size adequate pumps.
This unit can be installed with a direct venting system or with a one pipe vent system and draw
combustion air from the room.
The quality of the system water is very important. Poor water quality can damage heating
systems and boilers due to scale formation and corrosion.
2.4 Intended Use – Water Heaters and Boilers with AMR Option
This option is available for AERCO AM Series water heaters and boilers. All functional
descriptions that apply to AM water heaters and boilers apply to the AMR option, except where
specifically noted.
The AMR option reduces thermal loss by using a pump to efficiently recirculate a mix of building
recirculated water (if used on site), fresh potable water, and water in the lower portion of the
tank for heating in the heat exchanger. A functional diagram may be found at the end of this
chapter.

AM Series Boilers and Water Heaters
CHAPTER 2: FUNCTIONAL OVERVIEW
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2.5 AM Series Functional Schematics
2.5.1 AM 399 / 500 Functional Schematic
Figure 2-3: 399 / 500 (Boiler & Water Heater) Functional Schematic

AM Series Boilers and Water Heaters
CHAPTER 2: FUNCTIONAL OVERVIEW
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2.5.2 AM 750 Functional Schematic
Figure 2-4: 750 (Boiler & Water Heater) Functional Schematic

AM Series Boilers and Water Heaters
CHAPTER 2: FUNCTIONAL OVERVIEW
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2.5.3 AM1000 Functional Schematic
Figure 2-5: 1000 (Boiler & Water Heater) Functional Schematic

AM Series Boilers and Water Heaters
CHAPTER 2: FUNCTIONAL OVERVIEW
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2.5.4 AMR Functional Schematic
Figure 2-6: AMR Function Diagram (Buffer Tank Transparent for Clarity
MIXED BUILDING RECIRCULATION
AND MAKEUP WATER RETURN
TANK OUTLET TO
RECIRCULATION
LOOP
HOT WATER OUTLET
AM HEAT
EXCHANGER
INLET (FROM
WATER RETURN
AND TANK)
GAS INLET
AMR
RECIRCULATION
LOOP PIPING
HOT WATER OUTLET
(FROM AM HEAT
EXCHANGER TO
BUFFER TANK)
TANK INLET FROM
HEAT EXCHANGER
AM SERIES
WATER HEATER
BUFFER TANK
RECIRCULATION
LOOP PUMP
= Warm Tank Water
= Cold Return Water
= Hot Water
LWCO (LOW
WATER CUT-OFF)
= Tank and Cold Return Water

AM Series Boilers and Water Heaters
CHAPTER 3: INSTALLATION - SITE
OMM-0100_0D AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 19 of 154
GF-146 Ph.: 800-526-0288 03/28/16
CHAPTER 3: INSTALLATION - SITE
3.1 Choosing the Installation Location
This section describes the general installation considerations for the AM Series units.
WARNING!
Provisions for combustion air and ventilation of the boiler room are
always required, regardless whether the combustion air is taken
from the outside (Direct Vent, sealed combustion) or inside (room
air for combustion). Insufficient ventilation of the boiler room can
lead to high air temperatures. Make sure that intake and exhaust
openings are sufficiently sized and no reduction or closure of
openings takes place. If these are not provided, do not operate the
boiler.
WARNING!
LIQUEFIED PETROLEUM (L.P.) PROPANE GAS-FIRED
BOILER LOCATION REQUIRES SPECIAL ATTENTION: 1994
UNIFORM MECHANICAL CODE, section 304.6: “LPG
Appliances. Liquefied petroleum gas-burning appliances shall not
be installed in a pit, basement or similar location where heavier-
than-air-gas might collect. Appliances so fueled shall not be
installed in an above grade under-floor space or basement unless
such location is provided with an approved means for removal of
unburned gas.”
This appliance is not designed for direct outdoor installation. If installed outside of the structure,
it must be sheltered so it is protected from rain, wind, sun and frost. NEVER place this appliance
in a location that would subject it to temperatures at or near freezing or excessively high
temperature. Failure to properly locate this unit can result in premature failure.
The boiler must NOT be installed on carpeting.
This appliance must be installed in a location so that any water leaking from the unit or piping
connections or relief valve openings will not cause damage to the area surrounding the unit or
any lower floors in the structure. When such locations cannot be avoided, it is recommended
that a suitable drain pan, adequately drained, be installed under the boiler. The pan must not
restrict combustion air flow.
When installed in a room with thin flooring, resonating noises may occur. Install noise reducing
parts if required.
Do not allow excessive dust to collect on the appliance.

AM Series Boilers and Water Heaters
CHAPTER 3: INSTALLATION - SITE
Page 20 of 154 AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 OMM-0100_0D
03/28/16 Ph.: 800-526-0288 GF-146
WARNING!
Do not store or use gasoline or other flammable vapors
or liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
• Donot try to light any appliance.
• Donot touch any electrical switch.
• Donot use any phone in the building.
• Immediately call your gas supplier from a neighbor’s
phone. Follow thegas supplier’s instructions.
• If you cannot contact your gas supplier, call the fire
department.
3.2 Boiler and Water Heater Installation Location Factors
When locating the boiler or water heater, the following factors must be considered:
•location of vent/air intakes;
•connection to the gas supply;
•connection to the water supply;
•connection to the heating system;
•connection to the electrical supply;
•disposal of the condensation produced by the boiler;
•connection to the room thermostat, building automation system, or equivalent device;
•piping of the safety relief valve discharge;
•connection of the outdoor temperature sensor;
•possible connection of an indirect water heater;
•If flooding is possible, elevate the boiler sufficiently to prevent water from reaching the unit;
•The location of vent/air intakes;
•connection to the gas supply;
•connection to the water supply;
•connection to the electrical supply;
•disposal of the condensation produced by the boiler;
•piping of the safety relief valve discharge;
•connection of a storage tank;
•If flooding is possible, elevate the boiler sufficiently to prevent water from reaching the unit;