Watts AERCO KC Series User manual

Printed in U.S.A. 10/8/01
GF-106
OMM-0008_0A
KC Series Gas Fired Boiler
USER MANUAL
Applicable for Serial Numbers G-01-026 to G-09-XXX
KC Series
Gas Fired
Boiler System
Semi
-
Instantaneous, Condensing,
Forced Draft,
Natural Gas and Propane Fired, Hot
Water Boiler
1,000,000 BTU/HR Input
Patent No. 4,852,524

Telephone Support
Direct to Aerco technical support
(8 to 5 pm EST, Monday through
Friday)
[phone]
Printing Third Edition
August 2000
Aerco International, Inc.
100 Oritani Drive
Blauvelt, NY 10913
© Aerco International, Inc., 1999
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
i
GF-106 THE AERCO KC1000 GAS FIRED BOILER
Operating & Maintenance Instructions
FOREWORD
Section 1 SAFETY PRECAUTIONS---------------------------1
Section 2 INSTALLATION PROCEDURES------------------2
2.1 Receiving the Unit
2.2 Unpacking
2.3 Installation
2.4 Gas Supply Piping
2.5 Electrical Supply
2.6 Mode of Operation and Field Control
Wiring
2.7 Enable/Disable Interlock
2.8 Fault Relay Wiring
2.9 Flue Gas Vent Installation
2.10 Combustion Air
2.11 Unit Initial Fill
Section 3 CONTROL PANEL COMPONENTS and
OPERATING PROCEDURES----------------------10
3.1 The Control Panel
3.2 The Temperature Controller
3.3 The Primary Menu
3.4 The Secondary Menu
3.5 The Annunciator Circuit
3.6 The Combustion Safeguard
3.7 Water Level Test and Reset
3.8 On\Off Switch
3.9 Starting Sequence
3.10 After Flame
3.11 Flame Test Jacks
3.12 Start \ Stop Levels
3.13 Auto Restarts
Switches
Section 4 INITIAL START-UP-----------------------------------18
4.1 Initial Start-Up requirements
4.2 Tools and Instrumentation for
Combustion Calibration
4.3 Combustion Calibration
4.4 Propane Combustion Calibration
4.5 Boiler Reassembly
4.6 Mode of Operation Setup
4.7 Over Temperature Limit Switch
Adjustments
Section 5 BOILER MODE of OPERATION-------------------24
5.1 Indoor/Outdoor Reset Mode
5.2 Constant Setpoint Mode
5.3 4-20 ma Remote Setpoint Mode
5.4 4 to 20 ma Direct Drive Mode
5.5 Boiler Management System
5.6 Combination Control System
5.7 Using the Outside Air Sensor Feature

CONTENTS
ii
Section 6 SAFETY DEVICE
TESTING PROCEDURES---------------------------29
6.1 Testing of Safety Devices
6.2 Gas Pressure Fault Test
6.3 Low Water Level Fault Test
6.4 Water Temperature Fault Test
6.5 Flame Fault Test
6.6 Air Pressure Fault Test
6.7 Purge Interlocks Fault Test
6.8 Safety Pressure Relief Valve Test
Section 7 MAINTENANCE REQUIREMENTS----------------33
7.1 Maintenance Schedule
7.2 Spark Ignitor
7.3 Flame Detector
7.4 Combustion Calibration
7.5 Safety Device Testing
7.6 Manifold and Exhaust Tubes
Section 8 TROUBLESHOOTING--------------------------------38
8.1 Gas Pressure Fault
8.2 Exhaust Temperature Fault
8.3 Water Level Fault
8.4 Water Temperature Fault
8.5 Flame Fault
8.6 Air Pressure Fault
8.7 System Fault
APPENDICES:
A. Temperature Controller Menus
B. Temperature Controller Quick Reference
Chart
C. Temperature Sensor Resistance
Charts
D. Indoor\Outdoor Reset Ratio Charts
E. Mode of Operation Factory Default Settings
F. Dimensional & Parts Drawings
G. Piping Drawings
H. Wiring Schematics
I. Control Box Isometric Drawing
WARRANTIES

FOREWORD
iii
Foreword
The AERCO KC 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 14:1
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.
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 boiler module offer
selectable modes of operation and interface capabilities.
After prolonged shutdown, it is recommended that the startup procedures in Section 4 and 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 Aerco 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: _____________________________________________

SAFETY PRECAUTIONS
1
SECTION 1 - SAFETY PRECAUTIONS
Installing or operating personnel MUST, at
all times, observe all safety regulations. The
following warnings 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 instruction manual by AERCO, the
installation of unit’s 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 units, and ANSI/NFPA58 for LP
gas-fired units. Where applicable, the
equipment shall be installed in accordance
with CGA B149. Where ASME CSD-1 is
required by local jurisdiction, the installer
must conform to CSD-1.
WARNINGS!
MUST BE OBSERVED TO PREVENT
SERIOUS INJURY.
WARNING !
BEFORE PERFORMING ANY
MAINTENANCE ON THE UNIT, SHUT
OFF THE GAS SUPPLY AND THE
ELECTRICAL POWER SUPPLY TO
THE UNIT.
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 AND
CAREFULLY DECREASE ALL
TRAPPED PRESSURES TO ZERO
BEFORE PERFORMING ANY
MAINTENANCE.
WARNING !
DO NOT USE MATCHES, CANDLES,
FLAMES, OR OTHER SOURCES OF
IGNITION TO CHECK FOR GAS
LEAKS.
WARNING !
THE EXHAUST VENT PIPE
OPERATES UNDER A POSITIVE
PRESSURE AND MUST BE
COMPLETELY SEALED TO PREVENT
LEAKAGE OF COMBUSTION
PRODUCTS INTO LIVING SPACES.
CAUTIONS !
Must be observed to prevent equipment
damage or loss of operating
effectiveness.
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.
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.
NOTES:
Must be observed for effective
operating procedures & conditions.

INSTALLATION
2
SECTION 2 - INSTALLATION PROCEDURES
2.1. RECEIVING THE UNIT
Each KC unit is shipped as a single crated unit.
The shipping weight 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 by removing the
packaging material. 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
unit and are packed separately within the unit’s’
packing container
xSpare Spark Ignitor
xSpare Flame Detector
xManual 1-1/4" Gas Shutoff Valve
xDrain Valve Assembly
xASME Pressure Relief Valve
xIgnitor Removal Tool (One per Site)
xRegulator Adjustment Tool (One per
Site)
xTemperature/Pressure Gauge and
Fittings
x2 Lifting Lugs
xStainless Steel Condensate Cup
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

INSTALLATION
3
2.3 INSTALLATION
The unit must be installed with the prescribed
clearances for service as shown in Figure 2.1.
The minimum clearance dimensions, required by
AERCO, are listed below. Local building codes
may require more 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.
WARNING!
KEEP UNIT AREA CLEAR AND FREE
FROM COMBUSTIBLE MATERIALS AND
FLAMMABLE VAPORS AND LIQUIDS.
2.3.1. SETTING THE UNIT
Locate the lifting lugs, shipped with the unit and
attach them to the 5/8” x 11 studs at the top of
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" 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-568 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.
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.
Figure 2.3
Supply and Return Location

INSTALLATION
4
Whether installing single or multiple units, install
the piping and accessories as shown in the
appropriate piping diagram located in the
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 make-
up 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.
2.3.3 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 psig as
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 be manifolded,
(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).
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.
Figure 2.4
Relief and Drain Valve Location
Figure 2.5a
Pressure /Temperature Gauge Installation

INSTALLATION
5
Figure 2.5b
Pressure/Temperature Gauge Installation
2.3.5 CONDENSATE PIPING
The KC Boiler is designed to condense and the
installation must have provisions for drainage to
a suitable waste. A 1-3/4” inch O.D. silicone
hose, supplied with the unit, directs condensate
from the exhaust manifold to a stainless steel
condensate cup. The condensate cup is shipped
loose and should be installed inside the unit
directly under the manifold’s condensate
drainage hole (see FIG. 2.6). A 5/8-inch O.D.
flexible polypropylene tubing (or suitable
equivalent) can be used to carry the condensate
by gravity to a nearby floor drain. If a floor drain
is not available, a condensate pump can be
used to remove the condensate to drain. The
maximum condensate flow rate is 5 GPH. The
condensate cup and line must be removable for
routine maintenance. Do not hard pipe.
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.
Figure 2.6
Condensate Drain System Location
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.
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 non-
approved 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 sparingly. Any excess
must be wiped off to prevent clogging of
components.

INSTALLATION
6
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.
2.4.1 GAS SUPPLY PRESSURE
REGULATOR
An external, in-line, supply gas regulator
(supplied by others) should be positioned as
shown in figure 2.7. Union connections should
be placed in the proper locations to allow
maintenance of the regulator if required
NOTE:
An individual gas pressure regulator must
be installed upstream of each KC1000. The
regulator must regulate gas pressure to 8.5”
W.C. at 1,000,000 BTU/H for natural gas
and propane units.
The maximum static inlet pressure to the unit
must be no more than 14” water column.
Minimum gas pressure is 8.5” W.C. for FM gas
trains and 8.9” W.C. for IRI gas trains when the
unit is firing at maximum input. Gas pressure
should not exceed 10.5” 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 8.5” W.C. minimum for FM gas trains
and 8.9” W.C. for IRI gas trains at maximum
BTU input (1,000,000 BTU/HR) for natural gas
and propane 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. The
supply gas regulator must also be rated to
handle the maximum incoming gas pressure to
it. When the gas supply pressure will not exceed
14” W.C. a non-lock 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
requirements concerning venting of supply gas
regulators.
CAUTION!
A lockup style regulator must be used when
gas supply pressure exceeds 14” W.C.
Figure 2.7
Gas Supply Regulator and Manual Shut -Off
Valve Location
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 may be ordered pre-
assembled or as separate components. If either
IRI gas train option is ordered a complete
instructional package, detailing field installation
will be included. To obtain a copy of an IRI
instructional package prior to the equipment
shipping contact your local representative or
AERCO. (See appendix F)
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. The location
of the electrical wiring box is on the front right
side of the unit as shown in Figure 2.8.

INSTALLATION
7
Figure 2.8
AC Wiring Box Location
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, 1 Phase, 60 Hz, 20 Amps from a
dedicated electrical circuit. No other devices
should be on the same electrical circuit as a
KC unit. A disconnecting means 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 electrical wiring diagram is shown in Figure
2.9. 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 removed easily.
Figure 2.9
Electrical 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 a particular mode,
some field wiring may be required to complete
the installation. This wiring is typically to the
Field Control Wiring 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
sections.
Figure 2.10
Field Control Wiring Box Location
SSOV
ACTUATOR
BLOWER
FRAME
ELECTRICAL WIRING BOX
FIELD
CONTROL
GAS SHUT-OFF VALVE
BLOWER
BOX
WIRING
AERCO INTERNATIONAL INC.
157
INDICATION
-
+
FAULT
SHIELD
BMS
14
13
12
10
11
6
4
5
2
3
91
FIELD WIRING
START
168
-
+
4-20 mA
EXH.
TEMP.
SWITCH
AIR
SENSOR
OUTDOOR

INSTALLATION
8
2.6.1 CONSTANT SETPOINT MODE
No external field wiring connections other than
electrical supply connectins are required for this
mode. Although fault monitoring or
enable/disable interlocking wiring can be utilized
(see sections 2.7 and 2.8).
2.6.2 INDOOR/OUTDOOR RESET MODE
This mode of operation increases supply water
temperature as outdoor air temperature
decreases. An Outside Air Temperature Sensor
(AERCO PN 123525 MUST BE wired to the
Field Control Wiring Box using a two wire
shielded cable having a minimum of 22 AWG
(see Fig. 2.11). The cable shield is connected
only at the terminals provided in the field wiring
box. The sensor end of the shield must be left
free and ungrounded. There is no polarity in
terminating the sensor wires. When mounting
the Outdoor Air Temperature Sensor, it should
be mounted on the north side of the building in
an area where the average outside air
temperature is expected. The sensor should be
shielded from sun's direct rays, as well as direct
impingement by the elements. If a cover or
shield is used, it must allow free air circulation.
The sensor may be mounted up to two hundred
feet from the unit.
2.6.3 BOILER MANAGEMENT SYSTEM
MODE
When using multiple units, with an AERCO
Boiler Management System Panel, Model 168,
the field wiring is between the BMS Panel and
each unit’s field wiring box (see Fig. 2.11). A
twisted pair of 18 to 22 AWG wire must be
utilized for the connections. No shield is utilized
and polarity must be maintained. The Supply
Header Temperature Sensor (AERCO P/N
122790) must be wired back to the BMS Panel,
regardless of mode of operation. See the
instructions provided with the BMS for proper
location and wiring instructions.
2.6.4 4 to 20 ma REMOTE SETPOINT
MODE
The KC1000 can be controlled with a 4-20 ma
signal from a Building Management System or
an external controller. The supplied 4-20 ma
signal must be a floating (ungrounded) signal.
Connections between the 4-20 ma source and
the unit's field wiring box must be made using a
two wire shielded cable having a minimum
gauge of 22 AWG (see Fig. 2.11). The shield is
connected only at the terminal provided in the
field wiring box. The shield must be left free and
ungrounded at the source end. Polarity must be
maintained when connecting the wires.
2.6.5 COMBINATION MODE
With a Combination Mode unit, field wiring is
between the unit’s field wiring box, the CCP
(Combination Control Panel), and the BMS
(Boiler Management System). The wiring must
be done using a shielded twisted pair of 22
gauge wire and polarity must be maintained
between the unit, the CCP, and the BMS.
Control wire shielding should be secured at each
end of the wiring connections to the terminals
provided. For further instructions and wiring
diagrams consult the BMS and CCP instructions
2.7 ENABLE/DISABLE INTERLOCK
Each unit has an enable/disable interlock circuit
located in the field wiring box. This interlock
must be closed,(jumped), to allow the unit to fire.
When the interlock is open, the control panel
Annunciator will display 'INTERLOCK
DISABLED' and the unit will not fire. The unit
comes factory wired with the interlock closed.
Figure 2.11
Field Control Box Wiring
2.8 FAULT RELAY WIRING
The fault relay is a normally open, single pole,
single throw relay, that is energized upon any
fault condition. The relay will remain energized
until the fault is cleared and the CLEAR button is
pushed. The normally open field connections
are shown in Figure 2.11. The relay contacts are
rated for 5 amps at 250 VDC and 5 amps at 30
VDC.

INSTALLATION
9
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,
watertight 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 the has 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 used in gas-
fired 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 combustion air
supply venting are outlined below. For
combustion air supply from ducting, 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
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.
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.
2.11 UNIT INITIAL FILL
Before filling the unit’s shell for the first time,
blow out all the connecting water and gas piping
and check thoroughly for leaks. Rinse all soap
suds from the gas piping with clean water. Do
not allow water to get on the control panel or
electrical connections. Check that all installation
procedures have been completed before filling
the unit.
The following steps should be followed when
filling the unit:
1. Close the unit’s drain valve.
2. Open the system return connection on the
bottom of the unit.
3. Make certain that the system pressure
reducing fill valve is on to replenish pressure
in the system as the unit fills.
4. Using the pressure/temperature gauge,
supplied with the unit, as a guide, allow
pressure to slowly build up in the unit.
5. Slowly open either the manual vent valve or
the supply valve off its seat, allowing air to
vent from the unit’s shell.

CONTROL PANEL OPERATING PROCEDURES
10
SECTION 3- CONTROL PANEL OPERATING PROCEDURES
The following is a guide to the operation of the
control panel. Initial start-up of this unit must be
performed by factory trained start-up personnel.
Operation prior to initial start-up by factory
trained personnel will void the warranty.
CAUTION:
All initial installation procedures must be
satisfied before attempting to start the unit.
WARNING:
DO NOT ATTEMPT TO DRY FIRE THE KC
1000. 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.
3.1 THE CONTROL PANEL
The KC 1000 Control Panel has been designed
to provide the operator with all the necessary
information required for operating and
troubleshooting this unit. There are six separate
accessible controls or displays, available to the
operator, (see Fig. 3.1). These are:
1. The Temperature Controller
2. The Annunciator & Function Switches
3. The Combustion Safeguard Controller
4. Water Level Test and Reset Switches
5. On/Off Switch
6. Fault Indicator Light
The following sections will describe the above
components in more detail.
WARNING
CONTROL BOX INTERNALS MUST NOT
BE SERVICED OR ACCESSED BY
OTHER THAN FACTORY CERTIFIED
SERVICE TECHNICIANS. ALL CONTROL
BOX INTERNALS HAVE THE CAPABILITY
OF HOLDING AN ELECTRICAL VOLTAGE
OF 120 VOLTS AC.
3.2 THE TEMPERATURE CONTROLLER
The temperature controller is a PID
programmable controller that utilizes feed
forward and feedback information to accurately
maintain a desired set point. It is the primary
source for programming and viewing operating
parameter settings. It plays a part in the start
sequence and includes other features such as:
x2- eight segment LED displays
x5 indicator status lights
x3 menu levels
xRS-485 communications capability
Figure 3.1
Front Panel Controls Location
3.2.1 LED DISPLAYS
The upper and lower displays each consists of
four, 8 segment LED’s (see Fig. 3.2). When
choosing an operating parameter to be changed
or looked at, the lower LED display indicates the
parameter being looked at in the form of a code.
The upper display indicates the parameter’s
value. For a complete listing of the operating
parameters, see Appendix A of this manual.
3.2.2 INDICATOR STATUS LIGHTS
The first LED indicator light, “MAN” indicates
whether the controller is in auto or manual
mode, (see Fig 3.2). When lit the controller is in
manual mode and the operator is responsible for
operation of the unit. When the LED is not lit the
controller is in auto mode. In auto mode the
controller is operating the unit from signals
generated by sensors located on the unit or in
the system, or by signals from an energy
management system.
The second LED, “REM”, designates whether
the controller is being controlled locally or
remotely, (see Fig. 3.2). When lit the controller is
in remote mode and can accept commands from
an external source via the RS-485 interface.
When this LED is not lit the controller is in local
mode and will respond to whatever the current
internal settings are. All external commands are
ignored.

CONTROL PANEL OPERATING PROCEDURES
11
The third LED, “ON”, indicates the status of the
start relay, (see Fig. 3.2). The start relay is
internal to the controller and is part of the start
string for the unit. When this LED is lit there is a
demand for heat and the start relay is closed.
The last two LED’s, “oF” and “oC”, indicate
whether the temperature displayed is qF or qC,
(see Fig. 3.2).
NOTE:
When the temperature controller is displaying in
oC only the temperature being displayed is
affected. All other settings remain in oF.
Figure 3.2
Temperature Controller Operating Status Lights
3.2.3 MENU LEVELS
The temperature controller has two menu levels
that are operator accessible for programming
the unit functions and parameters. These are the
Primary and Secondary menus:
To change from the primary menu to the
secondary menu, simultaneously depress the ×
arrow key and ENTER button. To change from
the secondary to the primary menu
simultaneously press the arrow key and the
INDEX button.
To scroll through a menu, depress the INDEX
button. To change a parameter scroll through
the menu until the desired parameter is
indicated on the controller’s lower LED display.
Then use the ×Øarrow keys to change the
parameters value. Once a parameters value has
been changed the ENTER key must be
depressed for the change to be recognized by
the controller. Leaving the desired parameter
without entering the new value will result in that
parameters value defaulting back to the original
value. Detailed descriptions and instructions for
accessing each menu parameter are listed
within this section.
For more data concerning the minimum and
maximum range, and factory defaults of menu
parameters, see Appendix E of this manual.
Each menu level is described below.
3.3 THE PRIMARY MENU
The primary menu is the default menu. When in
another menu level and there is no activity for 5
minutes the temperature controller will default
back to the primary menu. The Primary menu
allows the operator access to the following
temperature controller parameters:
Code Meaning
tout Actual unit outlet water temperature.
pct Current firing rate of the unit in
percent.
Setp The desired set point of outlet water
temperature.
Auto Automatic controlling mode ON or
OFF.
3.3.1 OUTLET TEMPERATURE (tout)
Outlet temperature is the actual outlet water
temperature of the unit. To access outlet
temperature press the INDEX button until (tout)
is displayed in the lower LED. The variables
under this feature may not be manually
changed. Fig. 3.3 below shows an outlet
temperature of 120º F
Figure 3.3
Outlet Temperature Display
3.3.2 PERCENTAGE OF FIRING RATE
(Pct)
Percentage of firing rate is a number, in percent,
that is related to the input BTU’s of the unit. For
instance a 50% firing rate equals approximately
500,000 BTU gas input while a 75 % firing rate
equals approximately 750,000 BTU gas input.
CAUTION:
Do not leave the unit unattended while in
the manual mode of operation.

CONTROL PANEL OPERATING PROCEDURES
12
To access the percent of firing rate press the
INDEX button while in the primary menu until
(Pct) is displayed in the lower LED. Use the ×Ø
arrow key to increase or decrease the
percentage of firing rate. Press the ENTER
button to accept the desired change. Figure 3.4
shows the temperature controller displaying a
100% firing rate.
Figure 3.4
Percent of Firing Rate Display
WARNING:
WHEN SWITCHING FROM AUTO TO
MANUAL MODE, THE FIRING RATE
DOES NOT CHANGE. THE UNIT WILL
CONTINUE TO OPERATE AT THE SAME
FIRING RATE PERCENTAGE AS WHEN
THE UNIT WAS IN AUTO MODE.
3.3.3 SETPOINT (Setp)
Setpoint is the desired outlet water temperature
that is to be maintained by the unit when in
automatic mode. Fig 3.5 shows the controller
with a setpoint of 120º F.
To access the unit’s setpoint press the INDEX
button until (Setp) is displayed in the lower LED.
To increase or decrease the unit’s setpoint press
the ×Øarrow keys. Press the ENTER button to
accept the change.
Figure 3.5
Setpoint Display
NOTE:
Changing the setpoint will only be
recognized when the unit is in the automatic
mode.
3.3.4 AUTOMATIC / MANUAL (Auto)
When set to automatic mode the controller is
receiving and processing inputs from
temperature sensor(s) located externally or on
the unit. The controller uses these inputs to
automatically decrease or increase the firing rate
to match the load.
In manual mode the controller no longer
automatically controls the firing rate of the unit. It
is up to the operator to control the outlet
temperature and firing rate. Manual mode is
commonly used for service and troubleshooting
the unit. All safety limits remain functional
whether the controller is in automatic or manual
mode.
To place the controller in automatic mode press
the INDEX button until (Auto) is displayed in the
lower LED.
Now press the ×Øarrow keys until ON is
displayed in the upper LED (see fig 3.6). Press
the enter button to accept the change. The MAN
LED should not be lit.
Figure 3.6
Auto/ Manual Display with Auto On
To place the KC 1000 in manual mode, press
the ×Øarrow keys until OFF is displayed in the
upper LED (see Fig 3.7). Press the enter button
to accept the change. The MAN LED should
now be lit.

CONTROL PANEL OPERATING PROCEDURES
13
Figure 3.7
Auto/Manual Display with Manual On
3.4 THE SECONDARY MENU
The secondary menu is primarily related to
temperature control. It is necessary to access
this menu when setting PID values or changing
the unit mode of operation. All the parameters
accessible in the primary menu are also
accessible in the secondary menu.
To access the secondary menu, press the ×
arrow key and ENTER simultaneously. To scroll
through the menu press the INDEX button. For a
complete explanation of the secondary menu
parameters see Appendix A of this manual.
3.5 THE ANNUNCIATOR CIRCUIT
The annunciator consists of the annnciator
circuit board, the front panel LCD display, and 4
function switches, (see Fig. 3.8 for the display
and function switch locations and see Appendix I
for the circuit board locations). The annunciator
circuit board is the interface between the LCD
display and the combustion safeguard system. It
monitors the unit during every phase of
operation and prompts the LCD display with
start sequence and fault messages. The function
switches are used to reset the annunciator and
gain access to the annunciator’s three function
displays.
The annunciator circuit board and LCD display
are not an integral part of the start sequence or
combustion safeguard system.
The annunciator start sequence messages, fault
messages, function switches and function
displays are explained below.
3.5.1 ANNUNCIATOR FUNCTION
SWITCHES and DISPLAYS
The Annunciator has three function displays
available to the operator. These are the MAIN,
the CYCLES, and the SET DATE displays.
These displays are accessed using the four
membrane switches located directly under the
LCD display on the front of the control panel.
They are labeled CLEAR, ×, Ø, and AUX.
Figure 3.8
Annunciator Function Switches and LCD Display
The MAIN display is used during normal
operation of the unit. In the MAIN display, start
sequence and fault messages can viewed. To
return to the MAIN display from any other
display, simultaneously press CLEAR and the ×
arrow key. To reset the MAIN display after a
fault has occurred press the CLEAR button.
The CYCLES display indicates the date and
time, and the number of cycles the unit has
started. When in the CYCLES display only the
number of cycles can be reset. To reset the
number of cycles to 0, simultaneously press the
×, and Øarrow keys and hold them for
approximately four seconds.
In the SET DATE display, both the time and date
are displayed and can be changed.
To access the SET DATE display, press the
CLEAR button while in the CYCLES display.
Continue pressing the CLEAR button to move
through the SET DATE display fields. Use the ×
Øarrow keys to set the date and time.
The following table shows the messages
displayed after accessing the CYCLES and SET
DATE displays.

CONTROL PANEL OPERATING PROCEDURES
14
# CYCLES =
“DATE” “TIME”
The number of times
the controller has
completed it’s start
cycle, and the time
and date
SET DATE:
“DATE” “TIME”
Displays and allows
setting of the date
and time
3.5.2 ANNUNCIATOR FAULT
MESSAGES
The following table lists the Annunciator MAIN
display fault messages and their meanings.
MESSAGE MEANING
RESET MAIN
POWER
AC power has been
interrupted. Power must
be shut off for 5
seconds to reset the
display.
HIGH WATER
TEMP
The unit has tripped
due to the outlet water
temperature exceeding
the high temperature
limit setting.
LOW GAS
PRESSURE
The unit has tripped
due to low gas
pressure.
LOW WATER
LEVEL
The shell water level is
below the probe level.
REMOTE
DISABLED
The interlock terminals,
in the relay box, are not
closed.
PURGE INTLK
OPEN
The proof of closure, or
the purge switch did not
prove closed during the
start sequence.
LOW AIR FLOW
The airflow switch did
not prove closed during
the start sequence.
SYSTEM FAULT
PURGE
INTERLOCKS
The proof of closure or
purge switch did not
prove closed 45
seconds after the unit
attempted to start.
SYSTEM FAULT
LOW AIR
PRESSURE
The air pressure switch
did not prove closed 45
seconds after the unit
attempted to start.
FLAME FAULT
DURING
IGNITION TRIAL
Flame did not prove at
the end of the trial for
ignition period.
LOCKOUT RUN
AIR FLOW
The air pressure switch
opened after flame was
proven.
LOCKOUT RUN
FLAME
Flame signal was lost
after flame was proven.
LOCKOUT RUN
The combustion
safeguard is locked out.
HI EXHAUST
TEMP
The exhaust gas
temperature has
exceeded 500º F
3.5.3 ANNUNCIATOR START
SEQUENCE MESSAGES
The following table lists the annunciator MAIN
display start sequence messages.
MESSAGE MEANING
STANDBY
The unit is in standby
mode waiting for a call
for heat
PURGING The unit is in the 7-sec
purge.
IGNITION TRIAL
The unit is in ignition
position attempting to
light the burner
FLAME PROVEN
The unit has
established flame and
is firing.
3.6 THE COMBUSTION SAFEGUARD
The Combustion Safeguard is responsible for
monitoring the safety components during the
start sequence, and after flame is established. It
is also responsible for the timing the purge and
ignition cycles during the start sequence.
The combustion safeguard is located on the left
side of the control panel as shown in Figure 3.9.
There are five status LED’s that indicate the
status of operation. Along with the annunciator,
these are useful as a double check for proper
system operation and troubleshooting.
The table below defines the function of each
light. The reset button located under the LED’s
is to reset the combustion safeguard a lockout.
DESCRIPTION FUNCTION
POWER Lights upon power up of
the unit.
PILOT Lights when the re is a call
for heat.
FLAME Lights once flame has
been detected.
MAIN
Lights after flame has
been detected and
stabilized
ALARM
This lights when the
controller is in a
LOCKOUT condition.

CONTROL PANEL OPERATING PROCEDURES
15
Figure 3.9
Combustion Safeguard Status Indicator LED
Location
3.7 WATER LEVEL TEST and RESET
SWITCHES
The water level switches are located on the left
side of the control box, see Fig. 3.10). When
depressed the TEST switch simulates a low
water level condition by breaking the connection
between the water level probe and the sensing
circuitry. To test the low water level circuitry,
depress the test switch for 3 seconds. The unit
should fault resulting in the red fault light blinking
and the LED display showing LOW WATER
LEVEL.
Note:
Only water level circuitry is tested during the
above test. To determine if the probe is
functioning properly, the water level must be
reduced below the level of the probe.
To reset the unit, depress the water level reset
switch, the annunciator clear button, and if
necessary, the reset button on the combustion
safeguard.
3.8 ON/OFF SWITCH
The ON/OFF switch is located on the right side
of the control panel above the temperature
controller (see Fig. 3.1). It is part of the start
string and must be in the ON position to enable
the unit to fire. When the switch is in the ON
position and illuminated, it is indicating that the
start limit string, consisting of water temperature,
gas pressure, water level, and the interlock is
satisfied, and that the alarm relay is not
activated. The unit at this point is in standby
mode and ready to run.
Figure 3.10
Water Level Test and Reset Switch Locations
3.9 STARTING SEQUENCE
When the unit is in the standby mode, and there
is a demand for hot water, the following will
occur:
1. Upon demand the temperature controller’s
ON status indicator will light.
2. The combustion safeguard’s PILOT LED
lights and the blower contactor energizes,
starting the blower.
3. The system next checks for proof of closure
from the safety shut-off valve, (see Fig.
3.11), and the air fuel valve rotates open
engaging the air /fuel valve open switch (see
Fig. 3.12).
4. The LCD display shows PURGE INTLK
OPEN until the above conditions are met.
Once met the LCD display will show LOW
AIR FLOW.
5. The blower proof switch closes, (See Fig.
3.13), and the LCD display will show
PURGING.
6. Closure of the blower proof switch signals
the combustion safeguard to begin its 7-
second purge cycle.