Watts AERCO Benchmark 2.0 User manual

GF-110
OMM-0020_0A
Benchmark 2.0 Gas-Fired Boiler
USER MANUAL
Applicable for Serial Numbers G-02-533 thru G-10-1060
Benchmark 2.0
Gas Fired
Boiler System
Condensing, Modulating
Forced Draft, Hot Water Boiler
2,000,000 BTU/H Input
Patent # : 2.155.12

GF-110
OMM-0020_0A
Benchmark 2.0 Gas-Fired Boiler
USER MANUAL
Telephone Support
Direct to AERCO Technical Support
(8 to 5 pm EST, Monday through Friday)
[phone]
AERCO International, Inc.
100 Oritani Drive
Blauvelt, NY 10913
www.aerco.com
© AERCO International, Inc., 2009
The information contained in this operation and maintenance 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 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.

CONTENTS
i
GF-110 - THE AERCO BENCHMARK 2.0 GAS FIRED BOILER
Operating & Maintenance Instructions
FOREWORD A
Chapter 1 – SAFETY PRECAUTIONS 1-1
Para.
Subject
Page
1-1
Safety Warnings
1-1
1-2
Emergency Shutdown
1-2
Para.
Subject
Page
1-3
Prolonged Shutdown
1-2
Chapter 2 – INSTALLATION PROCEDURES 2-1
Para.
Subject
Page
2.1
Receiving the Unit
2-1
2.2
Unpacking
2-1
2.3
Installation
2-2
2.4
Gas Supply Piping
2-3
2.5
Electrical Supply
2-5
2.6
Mode of Operation and Field
Control Wiring
2-6
Para.
Subject
Page
2.7
I/O Box Connections
2-8
2.8
Auxiliary Relay Contacts
2-9
2.9
Flue Gas Vent Installation
2-9
2.10
Combustion Air
2-10
Chapter 3 – CONTROL PANEL COMPONENTS AND
OPERATING PROCEDURES 3-1
Para.
Subject
Page
3.1
Introduction
3-1
3.2
Control Panel Description
3-1
3.3
Control Panel Menus
3-3
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
3-7
3.8
Start Sequence
3-7
3.9
Start/Stop Levels
3-9
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
4-3
Para.
Subject
Page
4.4
Combustion Calibration for
Propane on Dual Fuel Unit
4-5
4.5
Unit Reassembly
4-6
4.6
Over-Temperature Limit Switch
4-7

CONTENTS
ii
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
6-1
6.4
Low Water Level Fault Test
6-2
6.5
Water Temperature Fault Test
6-2
6.6
Interlock Tests
6-2
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
6-4
6.10
Purge Switch Open During
Purge
6-5
6.11
Ignition Switch Open During
Ignition
6-5
6.12
Safety Pressure Relief Valve
Test
6-5
Chapter 7 – MAINTENANCE REQUIREMENTS 7-1
Para.
Subject
Page
7.1
Maintenance Schedule
7-1
7.2
Spark Igniter
7-1
7.3
Flame Detector
7-2
7.4
Combustion Calibration
7-2
7.5
Safety Device Testing
7-3
7.6
Burner
7-3
Para.
Subject
Page
7.7
Condensate Drain Trap
7-4
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

CONTENTS
iii
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
Benchmark Dual-Fuel Propane
Switch-Over Instructions
K-1
WARRANTIES W-1

FOREWORD
A
Foreword
The AERCO Benchmark boiler is 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's 20:1 turn down ratio and condensing capability offers extremely
high efficiencies and makes the Benchmark ideally suited for modern low temperature, as well
as, conventional heating systems.
Whether used in singular or modular arrangements the Benchmark 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 integration.
For service or parts, contact your local sales representative or AERCO INTERNATIONAL.
NAME:
ORGANIZATION:
ADDRESS:
TELEPHONE:
INSTALLATION DATE: _____________________________________________

SAFETY PRECAUTIONS
1-1
CHAPTER 1 SAFETY PRECAUTIONS
1.1 WARNINGS & CAUTIONS
Installers and operating personnel MUST, at all
times, observe all safety regulations. The
following general warnings and cautions must be
given the same attention as specific precautions
included in these instructions. In addition to all
the requirements included in this 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.
See pages 1-2 and 1-3 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.
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 ANY BOILER
MAINTENANCE.
WARNING!
ELECTRICAL VOLTAGES UP TO 460
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.
CAUTIONS!
Must be observed to prevent equipment
damage or the 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.

SAFETY PRECAUTIONS
1-2
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
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

SAFETY PRECAUTIONS
1-3
monoxide detectors.
Extracted Information From 248 CMR 5.08 (2) – Continued
a. In the event that the side wall horizontally vented gas fueled equipment is installed in
a crawl space or an attic, the hard wired carbon monoxide detector with alarm and
battery back-up may be installed on the next adjacent floor level.
b. In the event that the requirements of this subdivision can not be met at the time of
completion of installation, the owner shall have a period of thirty (30) days to comply with
the above requirements; provided, however, that during said thirty (30) day period, a
battery operated carbon monoxide detector with an alarm shall be installed.
2. APPROVED CARBON MONOXIDE DETECTORS. Each carbon monoxide detector as
required in accordance with the above provisions shall comply with NFPA 720 and be ANSI/UL
2034 listed and IAS certified.
3. SIGNAGE. A metal or plastic identification plate shall be permanently mounted to the exterior
of the building at a minimum height of eight (8) feet above grade directly in line with the exhaust
vent terminal for the horizontally vented gas fueled heating appliance or equipment. The sign
shall read, in print size no less than one-half (1/2) inch in size, "GAS VENT DIRECTLY BELOW.
KEEP CLEAR OF ALL OBSTRUCTIONS".
4. INSPECTION. The state or local gas inspector of the side wall horizontally vented gas fueled
equipment shall not approve the installation unless, upon inspection, the inspector observes
carbon monoxide detectors and signage installed in accordance with the provisions of 248 CMR
5.08(2)(a)1 through 4.
(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)]