AER Benchmark 2.0 Guide

Printed in U.S.A. REVISED JUNE 14, 2010
Instruction
No.
AERCO INTERNATIONAL, Inc., Northvale, New Jersey, 07647 USA
GF-123
Installation, Operation
& Maintenance Instructions
Benchmark
2.0 Low NOx
Gas Fired
Boiler System
Natural Gas or Propane Fired
Condensing, Modulating,
Forced Draft, Hot Water Boiler
2,000,000 BTU/H Input
Applicable for Serial Numbers G-10-0927 and above

Telephone Support
Direct to AERCO Technical Support
(8 to 5 pm EST, Monday through Friday):
1-800-526-0288
AERCO International, Inc.
159 Paris Avenue
Northvale, NJ 07647-0128
www.aerco,com
© AERCO International, Inc., 2010
The information contained in this
installation, operation and mainte-
nance 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.

FOREWORD
Foreword
The AERCO Benchmark 2.0 Low NOx (LN) Boiler is a modulating unit. It represents 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 Benchmark 2.0LN, with
its 20:1 turn down ratio and condensing capability, provides extremely high efficiencies and
makes it ideally suited for modern low temperature, as well as, conventional heating systems.
The boiler operates at inputs ranging from 100,000 BTU/hr. to 2,000,000 BTU/hr. The output of
the boiler is a function of the unit’s firing rate and return water temperature. Output ranges from
99,000 BTU/hr. to 1,933,000 BTU/hr., depending on operating conditions.
When installed and operated on natural gas in accordance with this Instruction Manual, the
Benchmark 2.0LN Boiler complies 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 Benchmark 2.0LN offers the maximum
flexibility in venting with minimum installation space requirements. The Benchmark's advanced
electronics are available in several selectable modes of operation offering the most efficient
operating methods and energy management system integration.
For service or parts, contact your local sales representative or AERCO INTERNATIONAL.
NAME:
ORGANIZATION:
ADDRESS:
TELEPHONE:
INSTALLATION DATE: _____________________________________________
A

CONTENTS
GF-123 - AERCO BENCHMARK 2.0LN GAS FIRED LOW NOx BOILER
Operating & Maintenance Instructions
FOREWORD A
Chapter 1 – SAFETY PRECAUTIONS 1-1
Para. Subject Page
1-1 Warnings & Cautions 1-1
1-2 Emergency Shutdown 1-2
Para. Subject Page
1-3 Prolonged Shutdown 1-2
Chapter 2 – INSTALLATION 2-1
Para. Subject Page
2.1 Introduction 2-1
2.2 Receiving the Unit 2-1
2.3 Unpacking 2-1
2.4 Site Preparation 2-1
2.5 Supply and Return Piping 2-3
2.6 Condensate Drain and Piping 2-3
2.7 Gas Supply Piping 2-4
2.8 AC Electrical Power Wiring 2-5
Para. Subject Page
2.9 Modes of Operation and Field
Control Wiring 2-6
2.10 I/O Box Connections 2-8
2.11 Auxiliary Relay Contacts 2-10
2.12 Flue Gas Vent Installation 2-10
2.13 Combustion Air 2-10
Chapter 3 – CONTROL PANEL OPERATING PROCEDURES 3-1
Para. Subject Page
3.1 Introduction 3-1
3.2 Control Panel Description 3-1
3.3 Control Panel Menus 3-4
3.4 Operating Menu 3-5
3.5 Setup Menu 3-5
Para. Subject Page
3.6 Configuration Menu 3-6
3.7 Tuning Menu 3-8
3.8 Combustion Cal. Menu 3-8
3.8 Start Sequence 3-8
3.9 Start/Stop Levels 3-10
Chapter 4 – INITIAL START-UP 4-1
Para. Subject Page
4.1 Initial Startup Requirements 4-1
4.2 Tools and Instruments for
Combustion Calibration 4-1
4.3 Natural Gas Combustion
Calibration 4-2
Para. Subject Page
4.4 Propane Combustion Calibration 4-6
4.5 Unit Reassembly 4-8
4.6 Over-Temperature Limit
Switches 4-9
i

CONTENTS
Chapter 5 – MODE OF OPERATION 5-1
Para. Subject Page
5.1 Introduction 5-1
5.2 Indoor/Outdoor Reset Mode 5-1
5.3 Constant Setpoint Mode 5-2
5.4 Remote Setpoint Mode 5-2
5.5 Direct Drive Modes 5-3
Para. Subject Page
5.6 Boiler Management System
(BMS) 5-4
5.7 Combination Control System
(CCS) 5-5
Chapter 6 – SAFETY DEVICE TESTING PROCEDURES 6-1
Para. Subject Page
6.1 Testing of Safety Devices 6-1
6.2 Low Gas Pressure Fault Test 6-1
6.3 High Gas Pressure Test 6-2
6.4 Low Water Level Fault Test 6-2
6.5 Water Temperature Fault Test 6-2
6.6 Interlock Tests 6-3
6.7 Flame Fault Test 6-3
Para. Subject Page
6.8 Air Flow Fault Test 6-4
6.9 SSOV Proof of Closure Switch 6-5
6.10 Purge Switch Open During
Purge 6-5
6.11 Ignition Switch Open During
Ignition 6-6
6.12 Safety Pressure Relief Valve
Test 6-6
Chapter 7 – MAINTENANCE REQUIREMENTS 7-1
Para. Subject Page
7.1 Maintenance Schedule 7-1
7.2 Ignitor-Injector 7-2
7.3 Flame Detector 7-3
7.4 Combustion Calibration 7-3
7.5 Safety Device Testing 7-3
7.6 Burner Assembly Inspection 7-3
Para. Subject Page
7.7 Condensate Trap 7-5
7.8 Shutting the Boiler Down For An
Extended Period of Time 7-5
7.9 Placing The Boiler Back In
Service After A Prolonged
Shutdown
7-5
Chapter 8 – TROUBLESHOOTING GUIDE 8-1
Para. Subject Page
8.1 Introduction 8-1
Para. Subject Page
ii

CONTENTS
Chapter 9 – RS232 COMMUNICATION 9-1
Para. Subject Page
9.1 Introduction 9-1
9.2 RS232 Communication Setup 9-1
Para. Subject Page
9.3 Menu Processing Utilizing
RS232 Communication 9-1
9.4 Data Logging 9-2
APPENDICES
App Subject Page
A Boiler Menu Item Descriptions A-1
B Startup, Status and Fault
Messages B-1
C Temperature Sensor Resistance
Chart C-1
D Indoor/Outdoor Reset Ratio
Charts D-1
E Boiler Default Settings E-1
App Subject Page
F Dimensional and Part Drawings F-1
G Piping Drawings G-1
H Wiring Schematics H-1
I Recommended Periodic Testing
Checklist I-1
J Benchmark Control Panel Views J-1
K Recommended Spare Parts K-1
3

SAFETY PRECAUTIONS
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). Where ASME CSD-1 is required by local
jurisdiction, the installation must conform to
CSD-1.
Where applicable, the equipment shall be
installed in accordance with the current
Installation Code for Gas Burning Appliances
and Equipment, CGA B149, 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.
WARNINGS!
MUST BE OBSERVED TO PREVENT
SERIOUS INJURY.
WARNING!
BEFORE ATTEMPTING TO PER-
FORM 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 THERE-
FORE MUST BE COMPLETELY
SEALED TO PREVENT LEAKAGE
OF COMBUSTION PRODUCTS INTO
LIVING SPACES.
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!
ELECTRICAL VOLTAGES UP TO
120 VAC ARE 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 SER-
VICING.
CAUTIONS!
Must be observed to prevent equip-
ment damage or loss of operating
effectiveness.
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.
1-1

SAFETY PRECAUTIONS
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.
IMPORTANT
The Installer must identify and indicate
the location of the emergency shutdown
manual gas valve to operating personnel.
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.
MANUAL GAS SHUTOFF VALVE
VALVE OPEN VALVE CLOSED
Figure 1-1
Manual Gas Shutoff Valve
IMPORTANT – FOR MASSACHUSETTS INSTALLATIONS ONLY
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.
•If a glycol solution is used as anti-freeze protection, a backflow preventer must be installed
upstream of the Fill/Makeup Valve.
•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.
1-2