AERCO GF-109LN User Manual

Instructio

n

GF-109LN

No.

AERCO INTERNATIONAL, Inc., Northvale, New Jersey, 07647 USA

Installation, Operation

& Maintenance Instructions

KC Series
Gas Fired
Low NOx
Boiler System

Natural Gas and Propane Fired,

Condensing and Forced Draft Hot Water Boiler

970,000 BTU/HR Input (Natural Gas)

1,000,000 BTU/HR Input (Propane)

Applicable to Serial Numbers G-03-807 and above

Patent No. 4,852,524

REVISED JANUARY, 2009

Telephone Support

Direct to AERCO Technical Support
(8am to 5 pm EST, Monday - Friday):

1-800-526-0288

AERCO International, Inc.
159 Paris Avenue
Northvale, NJ 07647-0128

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 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.

CONTENTS

GF-109LN - AERCO KC1000 GAS FIRED LOW NOx BOILER

Operating & Maintenance Instructions

FOREWORD A

SECTION 1 – SAFETY PRECAUTIONS 1-1

Para. Subject Page

1.1 Warnings & Cautions 1-1

1.2 Emergency Shutdown 1-2

SECTION 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 2-4

2.5 Electrical Supply 2-6

2.6 Mode of Operation and Field
Control Wiring

2-6

Para. Subject Page

1.3 Prolonged Shutdown 1-2

Para. Subject Page

2.7 I/O Box Connections 2-8

2.8 Auxiliary Relay Contacts 2-10

2.9 Flue Gas Vent Installation 2-10

2.10 Combustion Air 2-10

SECTION 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 3-3

3.4 Operating Menu 3-4

3.5 Setup Menu 3-4

Para. Subject Page

3.6 Configuration Menu 3-5

3.7 Tuning Menu 3-7

3.8 Start Sequence 3-7

3.9 Start/Stop Levels 3-9

SECTION 4 – INITIAL START-UP 4-1

Para. Subject Page

4.1 Initial Startup Requirements 4-1

4.2 Tools and Instrumentation for
Combustion Calibration

4.3 Natural Gas Combustion
Calibration

4-1

4-2

Para. Subject Page

4.4 Propane Combustion Calibration 4-5

4.5 Unit Reassembly 4-7

4.6 Over-Temperature Limit Switch
Adjustments

4-8

Section 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 Modes 5-2

5.5 Direct Drive Modes 5-3

Para. Subject Page

5.6 Boiler Management System
(BMS)

5.7 Combination Control System
(CCS)

5-4

5-5

i

CONTENTS

SECTION 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 Fault Test 6-1

6.4 Low Water Level Fault Test 6-2

6.5 Water Temperature Fault Test 6-2

6.6 Interlock Fault 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 6-4

6.10 Purge Switch Open During
Purge

6.11 Ignition Switch Open During
Ignition

6.12 Safety Pressure Relief Valve
Test

6-5

6-5

6-6

SECTION 7 – MAINTENANCE 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 7-2

Para. Subject Page

7.5 Safety Device Testing 7-2

7.6 Manifold and Exhaust Tubes 7-2

7.7 Heat Exchanger Water Side
Inspection

7.8 Condensate Drain Assembly 7-5

7-4

SECTION 8 – TROUBLESHOOTING 8-1

Para. Subject Page

8.1 Introduction 8-1

Para. Subject Page

APPENDICES

App Subject Page

A Boiler Menu Item Descriptions A-1
B Startup, Status and Fault

Messages

C Temperature Sensor Resistance

Chart

D Indoor/Outdoor Reset Ratio

Charts

B-1

C-1

D-1

App Subject Page

E Boiler Default Settings E-1
F Dimensional and Part Drawings F-1
G Piping Drawings G-1
H Wiring Schematics H-1
I KC1000 Control Panel Views I-1
J KC1000 Low NOx Dual-Fuel

Switch-Over Instructions

J-1

WARRANTIES W-1

ii

FOREWORD

Foreword

This system can be operated using natural gas or propane fuel. A simple spring change in the
differential regulator and combustion calibration is all that is needed to switch fuels.

The AERCO KC Low NOx 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 load tracking capability relates energy input directly to fluctuating system loads
through a 11:1 modulating turndown ratio. The boiler’s condensing capability offers extremely
high efficiencies and makes the KC Boiler ideally suited for modern low temperature, as well as,
conventional heating systems.

When installed and operated on natural gas in accordance with this Instruction Manual, the KC
Boiler complies with the NOx emission standards outlined in:

• South Coast Air Quality Management District (SCAQMD), Rule 1146.2

• Texas Commission on Environmental Quality (TCEQ), Title 30, Chapter 117,

In addition, when operated using propane fuel, the KC Boiler is certified by AERCO to provide
NOx emissions of less than 30 ppm at full rated input.

The KC Boiler can be used singular or in modular arrangements for inherent standby with
minimum space requirements. Venting capabilities offer maximum flexibility and allow
installation without normal restrictions. The advanced electronics of each KC Boiler control
system offer selectable modes of operation and interface capabilities.

After prolonged shutdown, it is recommended that the startup procedures in Section 4 and the
safety device test procedures in Section 6 of this manual be performed, to verify system
operating parameters. If there is an emergency, turn off the electrical power supply to the KC
Boiler or close the manual gas valve located before the unit. The installer is to identify the
emergency shut-off device. FOR SERVICE OR PARTS, contact your local sales representative
or AERCO INTERNATIONAL.

NAME:

ORGANIZATION:

ADDRESS:

TELEPHONE:

INSTALLATION DATE: _____________________________________________

Rule117.465.

A

SAFETY PRECAUTIONS

SECTION 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, 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
PERFORM ANY MAINTENANCE ON
THE UNIT, SHUT OFF ALL GAS AND
ELECTRICAL INPUTS TO THE UNIT.

WARNING!

THE EXHAUST VENT PIPE OF THE
UNIT OPERATES UNDER A
POSITIVE PRESSURE AND THERE­FORE MUST BE COMPLETELY
SEALED TO PREVENT LEAKAGE
OF COMBUSTION PRODUCTS INTO
LIVING SPACES.

WARNING

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 OF 120
VAC ARE USED IN THIS
EQUIPMENT. THEREFORE THE
COVER ON THE UNIT’S POWER
BOX (LOCATED ON THE FRONT
RIGHT SIDE OF THE UNIT UNDER
THE HOOD AND SHEET METAL
SIDE PANEL) MUST BE INSTALLED
AT ALL TIMES, EXCEPT DURING
MAINTENANCE AND SERVICING.

CAUTIONS!

Must be observed to prevent
equipment 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 system­operating 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.

Figure 1-1

Manual Gas Shutoff Valve

1-2

SECTION 2 - INSTALLATION PROCEDURES

2.1. RECEIVING THE UNIT

Each KC1000 Boiler is shipped as a single
crated unit. The crated shipping weight of the
unit is approximately 1500 pounds, and must be
moved with the proper rigging equipment for
safety and to avoid damages. The unit should be
completely inspected for shipping damage and
completeness at the time of receipt from the
carrier and before the bill of lading is signed.
Each unit has Tip-N-Tell indicator on the outside
of the crate that indicates if the unit has been
turned on its side. If the Tip-N-Tell indicator is
tripped, do not sign for the shipment. Request a
freight claim and inspection by a claims adjuster
before proceeding or refuse delivery of the
equipment.

2.2. UNPACKING

Carefully unpack the unit. Take care not to
damage the unit jacket when cutting away
packaging materials. An inspection of the unit
should be made to determine if damage during
shipment occurred that was not indicated by the
Tip-N-Tell. The freight carrier should be notified
immediately if any damage is detected. The
following accessories come standard with each

INSTALLATION

unit and are packed separately within the unit’s
packing container

• Spare Spark Ignitor

• Spare Flame Detector

• Manual 1-1/4" Gas Shutoff Valve

• Drain Valve Assembly

• ASME Pressure Relief Valve

• Differential Regulator Spring:

P/N 122548 (Propane) or
P/N 124803 (Natural Gas)

• Ignitor Removal Tool (One per Site)

• Regulator Adjustment Tool (One per

site)

• Temperature/Pressure Gauge and
Fittings

• 2 Lifting Lugs

• Stainless Steel Condensate Cup

• Shell Cap

• Wing Nut for Shell Cap

Optional accessories are also separately packed
within the unit’s packing container. Standard and
optional accessories shipped with the unit
should be identified and put in a safe place until
installation or use.

Figure 2.1. Boiler Clearances

2-1

2.3 INSTALLATION

The unit must be installed with the prescribed
clearances for service as shown in Figure 2.1.
The minimum
AERCO, are listed below. Local building codes
may require additional clearance and take
precedence

Minimum clearances required:
Sides 24"

Front 18"
Rear 18"
Top 18"

All gas piping, water piping, and electrical
conduit or cable must be arranged so that they
do not interfere with the removal of any cover, or
inhibit service or maintenance of the unit.

KEEP UNIT AREA CLEAR AND FREE
FROM COMBUSTIBLE MATERIALS AND

FLAMMABLE VAPORS AND LIQUIDS.

2.3.1. SETTING THE UNIT

Remove the unit from the wooden skid and
place in position using a block and tackle or
hoist attached to the lifting lugs, (see Fig. 2.2).
USE ONLY THE LIFTING LUGS TO MOVE
THE UNIT.

The KC-1000 is U/L approved for installation on
combustible flooring. A 4 to 6 inch high house­keeping concrete pad is recommended and
allows for sufficient drainage of the condensate.

It is suggested that units be secured using the
holes provided in the frame base. Piping must
not be used to secure the unit in place. See
drawing AP-A-816 in Appendix F for the base
frame dimensions.

In multiple unit installations, it is important to
plan the position of each unit. Sufficient space
for piping connections and future maintenance
requirements must be given. All piping must
include ample provision for expansion.

If installing a Combination Control (CCP)
system, it is important to identify and place the
Combination Mode units in the proper physical
location.

clearance dimensions, required by

WARNING!

Figure 2.2

Lifting Lug Location

2.3.2 SUPPLY AND RETURN PIPING

The locations of the 4" flanged system supply,
and return piping connections, to the unit are
shown in figure 2.3. The return connection is
located on the left side near the base of the
unit’s shell. The supply connection is located on
the left side near the top of the unit’s shell.

Whether installing single or multiple units, install
the piping and accessories as shown in the
appropriate piping diagram located in Appendix
G. For applications other than standard space
heating, consult the AERCO Boiler Application
Guide, GF-1070, or AERCO for the appropriate
piping schematics.

The minimum flow rate through the unit is 25
GPM and the maximum flow rate is 150 GPM.
Each unit is fitted with 4" flanges for high flow
application and the system velocity at the unit
return should not exceed 5 feet per second.
Each unit must have individual valves on the
supply, and return, for maintenance. In multiple
unit installations, the flow through each unit must
be balanced.

Every boiler plant must have a source of make­up water to it. As with any closed loop hydronic
system, air elimination and expansion equip­ment must be provided as part of the overall
installation. All piping MUST include ample
provision for expansion.

2-2

Figure 2.3

Supply and Return Location

INSTALLATION

2.3.4 TEMPERATURE/PRESSURE
INDICATOR

The unit is supplied with one of two styles of
Temperature/Pressure Indicators that must be
installed in the tapping on the supply flange of
the unit (see Figs. 2.5a and 2.5b). A suitable
pipe compound should be used sparingly to the
threaded connection.

2.3.3 PRESSURE RELIEF AND DRAIN
VALVE INSTALLATION

An ASME rated Relief Valve is supplied with
each unit. The supplied pressure relief valve
setpoint will be 30, 50, 75, 100, or 150
ordered from the factory. Install the pressure
relief valve in the tapping provided opposite the
system supply connection, (see figure 2.4). The
pressure relief valve should be piped in the
vertical position using the fittings supplied. A
suitable pipe compound should be used on the
threaded connections, and excess should be
wiped off to avoid getting any into the valve
body. The discharge from the relief valve should
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 should be allowed in the discharge
line. In multiple unit installations the relief valve
discharge lines must not
(connected), together. Each must be individually
run to a suitable discharge location. The drain
valve provided should be installed on the right
hand side of the unit towards the bottom of the
shell. The valve should be pointed in the down
position, (see Fig. 2.4).

psig as

be manifolded,

Figure 2.4

Relief and Drain Valve Location

Figure 2.5a

Pressure /Temperature Gauge Installation

2-3

Figure 2.5b

Pressure/Temperature Gauge Installation

2.3.5 CONDENSATE PIPING

The KC Boiler is designed to condense. There­fore, the installation site must include suitable
provisions for condensate drainage or collection.
A stainless steel condensate cup is separately
packed within the unit’s shipping container. To
install the condensate cup, pro-ceed as follows:

1. Remove the left side panel and only the left
half of the rear cover to provide access to the
exhaust manifold and burner (Figure 2.6).

2. Insert the 1-3/4 inch manifold drain hose into
the condensate cup. Allow the cup to rest on
the floor directly beneath the manifold drain
hole (Figure 2.6).

3. Attach a length of 3/4 inch I.D. polypropylene
tubing to the condensate cup drain tube and
route it to a floor drain. If a floor drain is not
available, a condensate pump can be used to
remove the condensate to drain. The
condensate drain line must be removable for
routine main-tenance. Therefore, DO NOT
hard-pipe.

4. Replace the rear cover and side panel on the
unit.

Figure 2.6

Condensate Drain System Location

2.4. GAS SUPPLY PIPING

The AERCO Gas Fired Equipment Gas Compo­nents and Supply Design Guide (GF-1030) must
be consulted before any gas piping is designed
or started.

WARNING!

DO NOT USE MATCHES, CANDLES,
FLAMES OR OTHER SOURCES OF

IGNITION TO CHECK FOR GAS LEAKS.

CAUTION!

Soaps used for gas pipe leak testing can be
corrosive to metals. Piping must be rinsed
thoroughly with clean water after leak
checks have been completed.

NOTE:

All gas piping must be arranged so that it
does not interfere with removal of any
cover, inhibit service or maintenance, or
prevent access between the unit and walls,
or another unit.

2-4

INSTALLATION

The location of the 1-1/4" inlet gas connection is
on the right side of the unit as shown in Figure

2.7.

All pipe should be de-burred and internally
cleared of any scale or iron chips before
installation. No flexible connectors or non­approved gas fittings should be installed. Piping
should be supported from floor or walls only and
must not be secured to the unit.

A suitable piping compound, approved for use
with gas, should be used spar ingly. Any excess
must be wiped off to prevent clogging of
components.

To avoid damage to the unit, when pressure
testing gas piping, isolate the unit from the
supply gas piping. At no time should there be
more than 14” W.C. the unit. Bubble test all
external piping thoroughly for leaks using a soap
and water solution or suitable equivalent. The
gas piping must meet all applicable codes.

Figure 2.7

Gas Supply Regulator and Manual Shut -Off

Valve Location

2.4.1 GAS SUPPLY PRESSURE

REGULATOR

A mandatory external, in-line, supply gas regu­lator (supplied by others) must be installed
upstream of each KC1000 and positioned as
shown in Figure 2.7. Union connections should
be placed in the proper locations to allow
maintenance of the regulator if required. The
regulator must be capable of providing the
required gas pressures for natural gas and
propane units as described in the paragraphs
which follow.

Natural Gas:

The maximum static inlet pressure to the unit
must be no more than 14” W.C. Minimum gas
pressure is 8.8” W.C. for FM gas trains and

9.2” W.C. for IRI gas trains when the unit is
firing at maximum input. Gas pressure should
not exceed 11.5” W.C. at any time when firing.
Proper sizing of the gas supply regulator in
delivering the correct gas flow and outlet
pressure is mandatory. The gas supply
pressure regulator must maintain the gas
pressure at a regulated 8.8” W.C. minimum
for FM gas trains and 9.2” W.C. for IRI gas
trains at maximum BTU input (970,000
BTU/HR) for natural gas installations. The
supply gas regulator must be of sufficient
capacity volume, (1000 cfh), for the unit and
should have no more than 1" droop from
minimum to full fire.

Propane:

The maximum static inlet pressure to the unit
must be no more than 14” W.C. Minimum gas
pressure is 7.7” W.C. for FM gas trains and

8.1” W.C. for IRI gas trains when the unit is
firing at maximum input. Gas pressure should
not exceed 11.5” W.C. at any time when firing.
Proper sizing of the gas supply regulator in
delivering the correct gas flow and outlet
pressure is mandatory. The gas supply
pressure regulator must maintain the gas
pressure at a regulated 7.7” W.C. minimum
for FM gas trains and 8.1” W.C. for IRI gas
trains at maximum BTU input (1,000,000
BTU/HR) for propane installations. The supply
gas regulator must be of sufficient capacity
volume, (400 cfh), for the unit and should
have no more than 1" droop from minimum to
full fire.

The supply gas regulator must be rated to
handle the maximum incoming supply gas
pressure. When the gas supply pressure will not
exceed 14” W.C. a non-lo ck up or flow through
style regulator may be used. When supply gas
pressure will exceed 14” W.C., a lock up style
regulator must be used. The gas supply
regulator must be propery vented to outdoors.
Consult the local gas utility for exact
ments concerning venting of supply gas
regulators.

require-

CAUTION!

A lockup style regulator must be used when
gas supply pressure exceeds 14” W.C.

2-5

2.4.2 MANUAL GAS SHUTOFF VALVE

A 1-1/4” manual gas shut-off valve is furnished
with each unit. The valve should be positioned
as shown in Figure 2.7. The manual gas shut-of
valve must be installed upstream of the supply
regulator in a readily accessible location.

2.4.3 IRI GAS TRAIN KIT

The IRI gas train is an optional gas train
required in some areas by code or for insurance
purposes. The IRI gas train is factory pre-piped
and wired. (See Appendix F, Drawing No. SD-A-

660).

2.5 ELECTRICAL SUPPLY

The AERCO Gas Fired Equipment Electrical
Power Wiring Guide, (GF-1060), must be
consulted in addition to the following material
before wiring to the unit is started. AC power
connection to the unit are made at the Power
Box.This box is located on the front right side of
the unit as shown in Figure 2.8. Conduit should
be run from the knockouts in the side of the box
in such a manner that it does not interfere with
the removal of any sheet metal covers. A flexible
electrical connection may be utilized to allow the
covers to be easily removed.

POWER BOX

NOTE:

All electrical conduit and hardware should
be installed so that it does not interfere with
the removal of any cover, inhibit service or
maintenance, or prevent access between
the unit and walls or another unit.

2.5.1 ELECTRICAL REQUIREMENTS

Electrical requirements for each unit are 120
VAC, Single Phase, 60 Hz, 20 Amps from a
dedicated electrical circuit. No other devices
should be on the same electrical circuit as the
KC1000 unit. A means for disconnecting AC
power from the unit (such as a service switch)
must be installed near the unit for normal opera­tion and maintenance. All electrical connections
should be made in accordance with the National
Electrical Code and/or with any applicable local
codes.

The AC power wiring diagram is shown in Figure

2.9.

FRAME

2-6

SSOV
ACTUATOR

Figure 2.8

AC Power Box Location

BLOWER

Figure 2.9

AC Power Wiring Diagram

2.6 MODE OF OPERATION and FIELD
CONTROL WIRING

The KC Boiler is available in several different
modes of operation. While each unit is factory
configured and wired for the mode specified on
the equipment order, some field wiring may be
required to complete the installation. This wiring
is typically routed to the Input/Output (I/O) Box
located on the left side of the unit beneath the
removable side panel (see Fig. 2.10). Field
wiring for each particular mode of operation is
described in the following paragraphs. For
additional information concerning modes of
operations, refer to Section 5.

Figure 2.10

Input/Output (I/O) Box Location

INSTALLATION

2.6.1 CONSTANT SETPOINT MODE

The Constant Setpoint Mode is used when it is
desired to have a fixed setpoint that does not
deviate. No wiring connections other than
electrical supply connections are required for
this mode. However, if desired, fault monitoring
or enable/disable interlock wiring can be utilized
(see paragraphs 2.7.9 and 2.7.10).

2.6.2 INDOOR/OUTDOOR RESET MODE

This mode of operation increases supply water
temperature as outdoor temperatures decrease.
An outside air temperature sensor (AERCO PN

122790) is required. The sensor MUST BE
wired to the I/O Box wiring terminals (see Fig.

2.11). For more information concerning the
outside air sensor installation, refer to paragraph

2.7.1. For programming and setup instructions
concerning the indoor/outdoor-reset mode of
operation, refer to Section 5, paragraph 5.1.

OUTDOOR SENSOR IN

SENSOR COMMON

AUX SENSOR IN

NOT USED

ANALOG IN

B.M.S. (PWM) IN

SHIELD

mA OUT

RS-485
COMM.

+

­+

-

+

­+

G

-

RELAY CONTACTS:
120 VAC, 30 VDC
5 AMPS RESISTIVE

DANGER

REMOTE INTL'K IN
EXHAUST SWITCH IN
DELAYED INTL'K IN

NOT USED

NC

FAULT RELAY

COM

120 VAC, 5A, RES

NO
NC

AUX RELAY

COM
NO

120 VAC, 5A, RES

NOT USED

120 VAC USED

NOT USED

IN THIS BOX

Figure 2.11

I/O Box Terminal Strip

2-7

2.6.3 BOILER MANAGEMENT SYSTEM

(BMS) MODE

NOTE

BMS Model 168 can utilize either pulse
width modulation (PWM) or RS485
Modbus signaling to the Boiler. BMS II
Model 5R5-384 can utilize only RS485
signaling to the Boiler.

When using an AERCO Boiler Management
System (BMS), the field wiring is connected
between the BMS Panel and each Boiler’s I/O
Box terminal strip (Figure 2-11). Twisted
shielded pair wire from 18 to 22 AWG must be
utilized for the connections. The BMS Mode can
utilize either pulse width modulation (PWM)
signaling, or RS485 Modbus signaling. For PWM
signaling, connections are made from the
AERCO Boiler Management System to the
B.M.S. (PWM) IN terminals on the I/O Box
terminal strip. For RS485 Modbus signaling,
connections are made from the BMS to the
RS485 COMM terminals on the I/O Box terminal
strip. Polarity must be maintained and the shield
must be connected only at the AERCO BMS.
The boiler end of the shield must be left floating.
For additional instructions, refer to Chapter 5,
paragraph 5.6 in this manual. Also, refer to GF­108M (BMS Model 168) and GF-124 (BMS II
Model 5R5-184), BMS -Operations Guides.

2.6.4 REMOTE SETPOINT and DIRECT

DRIVE MODES

The KC1000 Boiler can accept several types of
signal formats from an Energy Management
System or other source to control either the
setpoint (Remote Setpoint Mode) or firing rate
(Direct Drive Mode) of the Boiler. These formats
are:

4 to 20 mA/1 to 5 Vdc
0 to 20 mA/0 to 5 Vdc
PWM – (Pulse Width Modulated signal. See

paragraph 2.7.4)
Network – (RS485 Modbus. See para. 2.7.7)
While it is possible to control one or more boilers

using one of the above modes of operation, it
may not be the method best suited for the
application. Prior to selecting one of the above
modes of operation, it is recommended that you
consult with your local AERCO representative or
the factory for the mode of operation that will
work best with your application. For more

information on wiring the 4 to 20 mA / 1to 5VDC
or the 0 to 20 mA / 0 to 5 VDC, see paragraph

2.7.3.

2.6.5 COMBINATION MODE
NOTE

Only BMS Model 168 can be utilized for
the Combination Mode, not the BMS II
(Model 5R5-384).

With a Combination Mode unit, field wiring is
between the unit’s I/O Box, the CCP
(Combination Control Panel), and the BMS
Model 168 (Boiler Management System). The
wiring must be done using a shielded twisted
pair of 22 AWG wire. Polarity must be
maintained between the unit, the CCP, and the
BMS. For further instructions and wiring
diagrams, refer to the GF-108 Boiler
Management System Operations Guide and the
CCP-1 data sheet.

2.7 I/O BOX CONNECTIONS

The types of input and output/signals and
devices to be connected to the I/O Box terminals
shown in Figure 2.11 are described in the
following paragraphs.

CAUTION!

DO NOT make any connections to the I/O
Box terminals labeled “NOT USED”.
Attempting to do so may cause equipment
damage.

2.7.1 OUTDOOR SENSOR IN

An outdoor air temperature sensor (AERCO Part
No. 122790) will be required mainly for the
Indoor/Outdoor Reset mode of operation. It can
also be used with another mode if it is desired to
use the outdoor sensor enable/disable feature.
This feature allows the boiler to be enabled or
disabled based on the outdoor air temperature.
The factory default for the outdoor sensor is
DISABLED. To enable the sensor and or choose
an enable/disable outdoor temperature, see the
Configuration menu in Section 3 and Appendix
A.

The outdoor sensor may be wired up to 200 feet
from the boiler and is connected to the
OUTDOOR SENSOR IN and SENSOR
COMMON terminals in the I/O box (see Figs.

2.10 and 2.11). Wire the sensor using a twisted

shielded pair cable of 18-22 AWG wire. There is
no polarity when terminating the wires. The

2-8

INSTALLATION

shield is to be connected only to the terminals
labeled SHEILD in the I/O Box. The sensor end
of the shield must be left free and ungrounded.

When mounting the sensor, it must be located
on the North side of the building where an
average outside air temperature is expected.
The sensor must be shielded form direct sunlight
as well as impingement by the elements. If a
shield is used, it must allow for free air
circulation.

2.7.2 AUX SENSOR IN

The AUX SENSOR IN terminals can be used to
add an additional temperature sensor for
monitoring purposes. This input is always
enabled and is a view only input that can be
seen in the operating menu. The sensor must be
wired to the AUX SENSOR IN and SENSOR
COMMON and must be similar to AERCO
BALCO wire sensor P/N 12449. A resistance
chart for this sensor is provided in Appendix C.

2.7.3 ANALOG IN

The ANALOG IN + and – terminals are used
when an external signal is used to drive the
firing rate (Direct Drive Mode) or change the
setpoint (Remote Setpoint Mode) of the Boiler.
Either a 4 to 20 mA / 1 to 5 VDC or a 0 to 20
mA / 0 to 5 VDC signal may be used to vary the
setpoint or firing rate. The factory default setting
is 4 to 20 mA / 1 to 5 VDC, however this may be
changed to 0 to 20 mA / 0 to 5 VDC using the
Configuration Menu described in Section 3. If
voltage rather than current is selected as the
drive signal, a DIP switch must be set on the
PMC Board located inside the Control Box.
Contact the AERCO factory for information on
setting DIP switches.

All of the supplied signals must be floating
(ungrounded) signals. Connections between the
source and the Boiler’s I/O Box must be made
using twisted shielded pair of 18 –22 AWG wire
such as Belden 9841(see Fig. 211). Polarity
must be maintained and the shield must be
connected only at the source end and must be
left floating (not connected) at the Boiler’s I/O
Box.

Whether using voltage or current for the drive
signal, they are linearly mapped to a 40°F to
240°F setpoint or a 0% to 100% firing rate. No
scaling for these signals is provided.

2.7.4 B.M.S. (PWM) IN
NOTE

Only BMS Model 168 can utilize Pulse
Width Modulation (PWM), not the BMS II
(Model 5R5-384).

These terminals are used to connect the
AERCO Boiler Management System (BMS)
Model 168 to the unit. The BMS Model 168
utilizes a 12 millisecond, ON/OFF duty cycle.
This duty cycle is Pulse Width Modulated (PWM)
to control firing rate. A 0% firing rate = a 5% ON
pulse and a 100% firing rate = a 95% ON pulse.

2.7.5 SHIELD

The SHIELD terminals are used to terminate any
shields used on sensor wires connected to the
unit. Shields must only be connected to these
terminals.

2.7.6 mA OUT

These terminals provide a 4 to 20 mA output
that can be used to monitor setpoint (40°F to
220°F), outlet temperature (30°F to 245°F), or
fire rate (0% to 100%). This function is enabled
in the Configuration Menu (Section 3, Table 3.4).

2.7.7 RS-485 COMM

These terminals are used for RS-485 MODBUS
serial communication between the unit and an
external “Master”, such as a Boiler Management
System or other suitable device.

2.7.8 EXHAUST SWITCH IN

These terminals permit an external exhaust
switch to be connected to the exhaust manifold
of the boiler. The exhaust sensor should be a
normally open type switch (such as AERCO Part
No. 123463) that closes (trips) at 500

o

F.

2.7.9 INTERLOCKS

The unit offers two interlock circuits for inter­facing with Energy Management Systems and
auxiliary equipment such as pumps or louvers.
These interlocks are called the Remote Interlock
and Delayed Interlock (Fig. 2.11). The wiring
terminals for these interlocks are located inside
the I/O Box on the left side of the unit. The I/O
Box cover contains a wiring diagram which
shows the terminal strip locations for these inter­locks which are labeled REMOTE INTL’K IN and
DELAYED INTL’K IN. Both interlocks, described
in the following paragraphs, are factory wired in
the closed position.

2-9

NOTE:

Both the Delayed Interlock and Remote
Interlock must be in the closed position to
allow the unit to fire.

2.7.9.1 REMOTE INTERLOCK IN

The remote interlock circuit (REMOTE INTL’K
IN) is provided to remotely start (enable) and
stop (disable) the Boiler if desired. The circuit is
24 VAC and comes factory pre-wired closed
(jumpered).

2.7.9.2 DELAYED INTERLOCK IN

The delayed interlock circuit (DELAYED INTL’K
IN) is typically used in conjunction with the
auxiliary relay described in paragraph 2.8. This
interlock circuit is located in the purge section of
the start string. It can be connected to the
proving device (end switch, flow switch etc.) of
an auxiliary piece of equipment started by the
boiler’s auxiliary relay. The delayed interlock
must be closed for the boiler to fire. If the
delayed interlock is connected to a proving
device that requires time to close (make), a time
delay (Aux Start On Dly) that holds the start
sequence of the boiler long enough for for a
proving switch to make can be programmed.
Should the proving switch not prove within the
programmed time frame, the boiler will shut
down. The Aux Start On Dly can be
programmed from 0 to 120 seconds. This option
is locate in the Configuration Menu (Section 3).

2.7.10 FAULT RELAY

The fault relay is a single pole double throw
(SPDT) relay having a normally open and
normally close set of relay contacts that are
rated for 5 amps at 120 VAC and 5 amps at 30
VDC. The relay energizes when any fault con­dition occurs and remains energized until the
fault is cleared and the CLEAR button is
depressed. The fault relay connections are
shown in Figure 2.11.

2.8 AUXILIARY RELAY CONTACTS

Each KC Boiler is equipped with a single pole
double throw (SPDT) relay that is energized
when there is a demand for heat and de­energized after the demand for heat is satisfied.
The relay is provided for the control of auxiliary
equipment, such as pumps and louvers, or can
be used as a Boiler status indictor (firing or not
firing). Its contacts are rated for 120 VAC @ 5
amps. Refer to Figure 2.11 to locate the AUX
RELAY terminals for wiring connections.

2.9 FLUE GAS VENT INSTALLATION

The AERCO Venting and Combustion Air Guide,
GF-1050, must be consulted before any flue or
inlet air venting is designed or installed.
Suitable, U/L approved, positive pressure,
water-tight vent materials as specified in
AERCO’s GF-1050, must be used for safety and
UL certification. Because the unit is capable of
discharging low temperature exhaust gases, the
flue must be pitched back to the unit a minimum
of 1/4" per foot to avoid any condensate pooling
and to allow for proper drainage.

While there is a positive flue pressure during
operation, the combined pressure drop of vent
and combustion air systems must not exceed
140 equivalent feet of 0.81” W.C. Fittings as well
as pipe lengths must be calculated as part of the
equivalent length. For a natural draft installation
the draft must not exceed - 0.25” W.C. These
factors must be planned into the vent
installation. If the maximum allowable equivalent
lengths of piping are exceeded, the unit will not
operate properly or reliably.

2.10 COMBUSTION AIR

The AERCO Venting and Combustion Air Guide,
GF-1050, MUST be consulted before any flue or
combustion supply air venting is designed or
started. Combustion air supply is a direct
requirement of ANSI 223.1, NFPA-54, and local
codes. These codes should be consulted before
a permanent design is determined.

The combustion air must be free of chlorine,
halogenated hydrocarbons, or other chemicals
that can become hazardous when us ed in gas­fired equipment. Common sources of these
compounds are swimming pools, degreasing
compounds, plastic processing and refrigerants.
Whenever the environment contains these types
of chemicals, combustion air must be supplied
from a clean area outdoors for the protection
and longevity of the equipment.

The more common methods of supplying
combustion air are outlined below. For more
information on combustion air, consult the
AERCO GF-1050, Venting and Combustion Air
Guide.

2.10.1 COMBUSTION AIR FROM

OUTSIDE THE BUILDING

Air supplied from outside the building must be
provided through two permanent openings. For
each unit these two openings must have a free
area of not less than one square inch for each
4000 BTUs input of the equipment or 250

2-10

INSTALLATION

square inches of free area. The free area must
take into account restrictions such as louvers
and bird screens.

2.10.2 COMBUSTION AIR FROM INSIDE
THE BUILDING

When combustion air is provided from within the
building, it must be supplied through two
permanent openings in an interior wall. Each
opening must have a free area of not less than
one square inch per 1000 BTUH of total input or
1000 square inches of free area. The free area
must take into account any restrictions such as
louvers.

NOTE

KC1000 units equipped with Low NOx
Burners require an optional Cold Air
Damper for operation with Direct Vent/
Sealed Combustion. The Cold Air Damper
is also required when the unit is installed
in an area where the combustion air
supply temperature can drop below 55°F.
Refer to the following paragraph (2.10.3)
and GF-1050 for installation details.

2.10.3 SEALED COMBUSTION

The KC Boiler is UL approved for 100% sealed
combustion application when installed properly.
When a sealed combustion air application is
installed, the sealed combustion air piping must
be deducted from the maximum allowable
discharge piping amounts. Each unit must have
a minimum 6" diameter connection made to the
special Inlet Air Adapter # GP-18917 available
from AERCO. This adapter bolts directly on to
the air inlet of the unit’s blower. See installation
instructions with adapter. All inlet air ducts must
be sealed air tight.

In addition, Cold Air Damper # 99026 must be
installed. It should be located along the inlet duct
run as close as possible to the KC1000 (See
Figure 2.12). The Cold Air Damper must be
placed on individual sections (one Damper per
unit), not in a manifold section. The adjustment
screw on the Damper should be moved to the
center of the slot position and tightened 1/2 turn
past “finger-tight”. DO NOT over-tighten.

See AERCO Venting Guide GF-1050 for further
details.

Figure 2.12

Sealed Combustion Air Connection

2-11

CONTROL PANEL OPERATING PROCEDURES

SECTION 3 - CONTROL PANEL OPERATING PROCEDURES

3.1. INTRODUCTION

The information in this Section provides a guide
to the operation of the KC1000 Boiler using the
Control Panel mounted on the front of the unit.
It is imperative that the initial startup of this unit
be performed by factory trained personnel.
Operation prior to initial startup by factory
trained personnel will void the equipment
warranty. In addition, the following WARNINGS
and CAUTIONS must be observed at all times.

CAUTION:

All initial installation procedures must be
satisfied before attempting to start the unit.

WARNING:

THE ELECTRICAL VOLTAGES IN THIS
SYSTEM INCLUDE 120 AND 24 VOLTS
AC. IT MUST NOT BE SERVICED OR
ACCESSED BY OTHER THAN FACTORY
CERTIFIED SERVICE TECHNICIANS.

WARNING:

DO NOT ATTEMPT TO DRY FIRE THE
BOILER. STARTING THE UNIT WITHOUT
A FULL WATER LEVEL CAN SERIOUSLY
DAMAGE THE UNIT AND MAY RESULT IN
PERSONNEL INJURY OR PROPERTY
DAMAGE. THIS SITUATION WILL VOID
ANY WARRANTY.

3.2. CONTROL PANEL DESCRIPTION

The KC1000 Control Panel shown in Figure 3-1
contains all of the controls, indicators and
displays necessary to operate, adjust and
troubleshoot the KC1000 Boiler. These op­erating controls, indicators and displays are
listed and described in Table 3-1. Additional
information on these items are provided in the
individual operating procedures provided in this
Section.

Figure 3-1. Control Panel Front View

3-1

CONTROL PANEL OPERATING PROCEDURES

Table 3-1. Operating Controls, Indicators and Displays

ITEM

NO.

CONTROL, INDICATOR

OR DISPLAY

1 LED Status Indicators Four Status LEDs indicate the current operating status as

follows:

COMM

MANUAL

REMOTE

DEMAND

2 VFD Display Vacuum Fluorescent Display (VFD) consists of 2 lines, each

3

OUTLET
TEMPERATURE

Display

4 RS-232 Port Port permits a Laptop Computer or External Modem to be

5 READY Indicator Lights when all Pre-Purge conditions have been satisified.
6 ON/OFF Switch Enables and disables boiler operation.

7

LOW WATER LEVEL
TEST/RESET Switches

8 FAULT Indicator Red FAULT LED indicator lights when a boiler alarm

9 CLEAR Key Turns off the FAULT indicator and clears trhe alarm message

10 MENU Keypad Consists of 6 keys which provide the following functions for

MENU

BACK

Lights when RS-232 communication is occurring
Lights when the unit is being controlled using the front panel

keypad.
Lights when the unit is being controlled by an external signal

from an Energy Management System
Lights when there is a demand for heat.

capable of displaying up to 16 alphanumeric characters. The
information displayed includes:

Startup Messages
Alarm Messages
Operating Status Messages
Menu Selection

3–Digit, 7–Segment LED display continuously displays the

outlet water temperature. The °F or °C LED next to the

display lights to indicate whether the displayed temperature is
in degrees Fahrenheit or degrees Celsius.

connected to the boiler Control Panel.

Allow the operator to test the operation of the water level
monitor.

Pressing TEST opens the water level probe circuit and

simulates a Low Water Level alarm.

Pressing RESET resets the water level monitor circuit.
Pressing CLEAR resets the display.

condition occurs. An alarm message will appear in the VFD.

if the alarm is no longer valid. Lockout type alarms will be
latched and cannot be cleared by simply pressing this key.
Troubleshooting may be required to clear these types of
alarms

the Control Panel Menus:
Steps through the main menu categories shown in Figure 3-2.

The Menu categories wrap around in the order shown.
Allows you to go back to the previous menu level without

changing any information. Continuously pressing this key will
bring you back to the default status display in the VFD. Also,
this key allows you to go back to the top of a main menu
category.

FUNCTION

3-2

ITEM

NO.

10

(Cont.)

CONTROL PANEL OPERATING PROCEDURES

Table 3-1. Operating Controls, Indicators and Displays - Continued

CONTROL, INDICATOR

OR DISPLAY

▲ (Up) Arrow When in one of the main menu categories (Figure 3-2),

pressing this key will select the displayed menu category. If

the CHANGE key was pressed and the menu item is flashing,

pressing the ▲ arrow key will increment the selected setting.

▼ (Down) Arrow When in one of the main menu categories (Figure 3-2),

pressing this key will select the displayed menu category. If

the CHANGE key was pressed and the menu item is flashing,

pressing the ▼ (Down) arrow key will increment the selected
setting.

FUNCTION

CHANGE

Permits a setting to be changed (edited). When the

CHANGE key is pressed, the displayed menu item will begin

to flash. Pressing the ▲ or ▼ arrow key when the item is
flashing will increment or decrement the displayed setting.

ENTER

Saves the modified menu information in memory. The
display will stop flashing.

11 AUTO/MAN Switch This switch toggles the boiler between the Automatic and

Manual modes of operation. When in the Manual (MAN)
mode, the front panel controls are enabled and the MANUAL

status LED lights.

When in the Automatic (AUTO) mode, the MANUAL status

LED will be off and the front panel controls disabled.

12 FIRE RATE Bargraph 20 segment red LED bargraph continuously shows the Fire

Rate in 5% increments from 0 to 100%

3.3. CONTROL PANEL MENUS

The Control Panel incorporates an extensive
menu structure which permits the operator to set
up, and configure the unit. The menu structure
consists of four major menu categories as
shown in Figure 3-2. Each of the menus shown,
contain options which permit operating
parameters to be viewed or changed. The
menus are protected by a password to prevent
unauthorized use.

Prior to entering the correct password, the
options contained in the Operating, Setup,
Configuration and Tuning Menu categories can
be viewed. However, with the exception of
Internal Setpoint Temperature (Configuration
Menu), none of the viewable menu options can
be changed.

Once the valid password (159) is entered, the
options listed in the Setup, Configuration and
Tuning menus can be viewed and changed, if

3.3.1. Menu Processing Procedure

Accessing each menu and option is accom­plished using the Menu Keys shown in Figure 3-

1. Therefore, it is imperative that you be

thoroughly familiar with the following basic steps
before attempting to perform specific menu
procedures.

1. The Control Panel will normally be in the

Operating Menu and the VFD will display the
current unit status. Pressing the ▲ or ▼
arrow key will display the other available data
items in the Operating Menu.

2. Press the MENU key. The display will show

the Setup Menu which is the next menu
category shown in Figure 3-2. This menu
contains the Password option which must be
entered if other menu options will be
changed.

3. Continue pressing the MENU key until the

desired menu is displayed.

desired.

3-3

CONTROL PANEL OPERATING PROCEDURES

4. With the desired menu displayed, press the
▲ or ▼ arrow key. The first option in the
selected menu will be displayed.

5. Continue to press the ▲ or ▼ arrow key until
the desired menu option is displayed.
Pressing the ▲arrow key will display the
available menu options in the Top-Down
sequence. Pressing the ▼ arrow key will
display the options in the Bottom-Up
sequence. The menu options will wrap­around after the first or last available option
is reached.

6. To change the value or setting of a displayed

menu option, press the CHANGE key. The

displayed option will begin to flash. Continue
to press the ▲ or ▼ arrow key for the option
to be changed. The available menu option
choices will be displayed. The menu option
choices do not wrap around.

7. To select and store a changed menu option,

press the ENTER key.

OPERATION

PASSWORD

SETUP

CONFIGURATION

NOTE:

The following paragraphs provide brief descrip­tions of the options contained in each menu.
Refer to Appendix A for detailed descriptions of
each menu option. Refer to Appendix B for
listings and descriptions of displayed startup,

status and error messages.

3.4. OPERATING MENU

The Operating Menu displays a number of key
operating parameters for the unit as listed in
Table 3-2. This menu is “Read-Only” and does
not allow personnel to change or adjust any of
the displayed items. Since this menu is “Read­Only”, it can be viewed at any time without
entering a password. Press the ▲ arrow key to
display the menu items in the order listed (Top­Down). Pressing the ▼ arrow key will display
the menu items in reverse order (Bottom-Up).

3.5. SETUP MENU

The Setup Menu (Table 3-3) permits the
operator to set the unit password which is
required to change any of the menu options. To
prevent unauthorized use, a previously entered
password entry will time-out after 1 hour.
Therefore, the password must be reentered
when required. In addition to permitting
password entries, the Setup Menu is also used
to enter date and time, language to be used for
display messages, units of temperature
measurements and entries required for external
communication and control of the unit via the
RS-232 port. A view-only software version
display is also provided to indicate the current
Control Box software version.

3-4

TUNING

Figure 3-2. Menu Structure

CONTROL PANEL OPERATING PROCEDURES

NOTE

The Outdoor Temp display item shown with an asterisk in Table 3­2 will not be displayed unless the Outdoor Sensor function has
been enabled in the Configuration Menu (Table 3-4).

Table 3-2. Operating Menu

Available Choices or Limits

Menu Item Display Minimum Maximum Default

Status Message
Active Setpoint 40°F 240°F
Aux Temp 30°F 245°F
Outdoor Temp* -70°F 130°F
Fire Rate In 0% Max Fire Rate
Flame Strength 0% 100%
Run Cycles 0 999,999
Run Hours 0 999,999
Fault Log 0 9 0

Table 3-3. Setup Menu

Available Choices or Limits
Menu Item Display Minimum Maximum Default

Passsword 0 9999 0
Language English English
Time 12:00 am 11:59 pm
Date 01/01/00 12/31/99
Unit of Temp Fahrenheit

Comm Address 0 127 0
Baud Rate 2400

Software Ver 0.00 Ver 9.99

3.6. CONFIGURATION MENU

The Configuration Menu shown in Table 3-4
permits adjustment of the Internal Setpoint
(Setpt) temperature regardless of whether the
valid password has been entered. Setpt is
required for operation in the Constant Setpoint
mode. The remaining options in this menu
require the valid password to be entered, prior to
changing existing entries. This menu contains a
number of other configuration settings which
may or may not be displayed, depending on the
current operating mode setting.

Fahrenheit

Celsius

9600
4800
9600

19.2K

NOTE:

The Configuration Menu settings shown in
Table 3-4 are Factory-Set in accordance
with the requirements specified for each
individual order. Therefore, under normal
operating conditions, no changes will be

required.

3-5

CONTROL PANEL OPERATING PROCEDURES

Table 3-4. Configuration Menu

Available Choices or Limits
Menu Item Display Minimum Maximum Default

Internal Setpt Lo Temp Limit Hi Temp Limit 130°F
Unit Type Boiler

Unit Size 0.5 MBTU

Boiler Mode Constant Setpoint

Remote Signal
(If Mode = Remote
Setpoint, Direct Drive
or Combination)
Bldg Ref Temp
(If Boiler Mode =
Outdoor Reset)
Reset Ratio
(If Boiler Mode =
Outdoor Reset)
Outdoor Sensor Enabled or Disabled Disabled
System Start Tmp
(If Outdoor Sensor =
Enabled)
Setpt Lo Limit 40°F Setpt Hi Limit 60°F
Setpt Hi Limit Setpt Lo Limit 240°F 200°F
Temp Hi Limit 40°F 240°F 215°F
Max Fire Rate 40% 100% 100%
Pump Delay Timer 0 min 30 min 0 min
Aux Start On Dly 0 sec 120 sec 0 sec
Failsafe Mode Shutdown or Constant Setpt Shutdown
mA Output Setpoint, Outlet Temp,

Lo Fire Timer 2 sec 120 sec 2 sec
Setpt Limiting Enabled or Disabled Disabled
Setpt Limit Band 0°F 10°F 5°F

40°F 240°F 70°F

30°F 100°F 60°F

Water Heater

1.0 MBTU

1.5 MBTU

2.0 MBTU

2.5 MBTU

3.0 MBTU

Remote Setpoint

Direct Drive

Combination

Outdoor Reset

4 – 20 mA/1 – 5V

0 -20 mA/0 – 5V

PWM Input (BMS)

Network

0.1 9.9 1.2

Fire Rate Out, Off

Boiler

1.0 MBTU

Constant
Setpoint

4 – 20 mA,
1-5V

Off

3-6

CONTROL PANEL OPERATING PROCEDURES

3.7. TUNING MENU

The Tuning Menu items in Table 3-5 are Factory
set for each individual unit.

Table 3-5. Tuning Menu

Available Choices or Limits
Menu Item Display Minimum Maximum Default

Prop Band 1°F 120°F 70°F
Integral Gain 0.00 2.00 1.00
Derivative Time 0.0 min 2.0 min 0.0 min
Reset Defaults? Yes

3.8. START SEQUENCE

When the Control Box ON/OFF switch is set to
the ON position, it checks all pre-purge safety

switches to ensure they are closed. These
switches include:

• Safety Shut-Off Valve Proof of Closure
(POC) switch

• Low Water Level switch

• High Water Temperature switch

• High Gas Pressure switch

• Low Gas Pressure switch

If all of the above switches are closed, the

READY light above the ON/OFF switch will light

and the unit will be in the Standby mode.

When there is a demand for heat, the following
events will occur:

NOTE:

If any of the Pre-Purge safety device switches
are open, the appropriate fault message will be
displayed. Also, the appropriate fault messages
will be displayed throughout the start sequence,

if the required conditions are not observed.

1. The DEMAND LED status indicator will light.

2. The unit checks to ensure that the proof of
closure switch in the Safety Shut-Off Valve
(SSOV) is closed (Figure 3-3).

Do not change these menu entries unless
specifically requested to do so by Factory­Trained personnel.

No

No

Are You Sure?

Figure 3-3.

Safety Shut-Off Valve

3. With all required safety switches closed, a
purge cycle will be initiated and the following
events will occur:

3-7

CONTROL PANEL OPERATING PROCEDURES

(a) Blower relay energizes and turns on

blower.

(b) Air/Fuel Valve rotates to the full-open

purge position and closes purge position
switch. The dial on the Air/Fuel Valve
(Figure 3-4) will read 100 to indicate that
the valve is full-open (100%).

(c) The FIRE RATE bargraph will show

100%.

STEPPER

MOTOR

DIAL
(DETAIL “A”)

Figure 3-5.

Blower Proof Switch

5. Upon completion of the purge cycle, the
Control Box initiates an ignition cycle and the
following events occur:

100

DETAIL "A"

Figure 3-4.

Air/Fuel Valve In Purge Position

4. Next, the blower proof switch (Figure 3-5)

closes and the display will show Purging and

indicate the elapsed time of the purge cycle
in seconds. The normal (default) time for the
purge cycle is 7 seconds.

(a) The Air/Fuel Valve rotates to the low-fire

ignition position and closes the ignition
switch. The dial on the Air/Fuel Valve
(Figure 3-6) will read between 25 and 35
to indicate that the valve is in the low­fire position.

(b) The igniter relay is activated and

provides ignition spark.

(c) The gas Safety Shut Off Valve (SSOV)

is energized (opened) allowing gas to
flow into the Air/Fuel Valve.

6. Up to 7 seconds will be allowed for ignition to
be detected. The igniter relay will be turned
off one second after flame is detected.

7. After 2 seconds of continuous flame, Flame
Proven will be displayed and the flame

strength will be indicated. After 5 seconds,
the current date and time will be displayed in
place of the flame strength.

3-8

CONTROL PANEL OPERATING PROCEDURES

8. With the unit firing properly, it will be
controlled by the temperature controller

circuitry. The FIRE RATE will be continu-

ously displayed on the front panel bargraph.

9. Once the demand for heat has been
satisfied, the Control Box will turn off the gas

BLOWER

BURNER

valve. The blower relay will be deactivated
and the Air/Fuel Valve will be closed.

Standby will be displayed.

3.9. START/STOP LEVELS

The start and stop levels are the fire rate
percentages that start and stop the unit, based
on load. These levels are Factory preset as
follows:

• Start Level: 20%

• Stop Level: 16%

Normally, these settings should not require
adjustment.

Figure 3-6.

Air/Fuel Valve In Ignition Position

3-9