Watts AERCO CFR 3000 Operating manual

OMM-0164_A •9/20/2023

CONTENTS
•• •
Table of Contents
SECTION 1. SAFETY PRECAUTIONS ................................................................................ 5
1.1 WARNINGS & CAUTIONS .....................................................................................................................5
1.2 EMERGENCY SHUTDOWN...................................................................................................................6
1.3 PROLONGED SHUTDOWN...................................................................................................................6
1.4 IMPORTANT –FOR MASSACHUSETTS INSTALLATIONS.................................................................7
SECTION 2. EDGE CONTROLLER OPERATION................................................................ 8
2.1 INTRODUCTION.....................................................................................................................................8
2.2 LOGIN AND PASSWORD ENTRY.........................................................................................................9
SECTION 3. START SEQUENCE .......................................................................................10
3.1 INTRODUCTION...................................................................................................................................10
3.2 START SEQUENCE .............................................................................................................................10
3.3 START/STOP LEVELS ........................................................................................................................13
3.4 START/STOP LEVELS –AIR/FUEL & ENERGY INPUT.....................................................................14
SECTION 4. INITIAL START-UP.........................................................................................15
4.1 INITIAL START-UP REQUIREMENTS.................................................................................................15
4.2 TOOLS & INSTRUMENTS FOR COMBUSTION CALIBRATION........................................................15
4.2.1 Required Tools & Instrumentation .................................................................................................................15
4.2.2 Installing a Gas Supply Manometer ................................................................................................................16
4.2.3 Accessing the Analyzer Probe Port .................................................................................................................17
4.3 COMBUSTION CALIBRATION.............................................................................................................17
4.3.1 NATURAL GAS Manual Combustion Calibration .............................................................................................17
4.4 REASSEMBLY......................................................................................................................................20
4.5 OVER-TEMPERATURE LIMIT SWITCHES.........................................................................................20
4.5.1 Adjusting the Automatic Reset Limit Switch Temperature ............................................................................21
4.5.2 Resetting the Manual Reset Limit Switch .......................................................................................................21
4.5.3 Changing the Readout Between Fahrenheit and Celsius................................................................................22
4.6 STACK GUARD SENSOR OPERATION..............................................................................................22
SECTION 5. SAFETY DEVICE TESTING............................................................................23
5.1 TESTING OF SAFETY DEVICES.........................................................................................................23
5.2 LOW GAS PRESSURE TEST ..............................................................................................................23
5.3 HIGH GAS PRESSURE TEST .............................................................................................................24
5.4 LOW WATER LEVEL FAULT TEST.....................................................................................................24
5.5 WATER TEMPERATURE FAULT TEST..............................................................................................25
5.6 INTERLOCK TESTS.............................................................................................................................26
5.6.1 Remote Interlock Test.....................................................................................................................................26
5.6.2 Delayed Interlock Test ....................................................................................................................................26
5.7 FLAME FAULT TEST............................................................................................................................26
5.8 AIR FLOW FAULT TESTS - BLOWER PROOF & BLOCKED INLET SWITCHES..............................27
5.8.1 Blower Proof Switch Test................................................................................................................................27
5.8.2 Blocked Inlet Switch Test................................................................................................................................28
5.9 SSOV PROOF OF CLOSURE SWITCH CHECK.................................................................................29
5.10 PURGE SWITCH OPEN DURING PURGE........................................................................................29
5.11 IGNITION SWITCH OPEN DURING IGNITION .................................................................................30
5.12 SAFETY PRESSURE RELIEF VALVE TEST.....................................................................................30
SECTION 6. STANDALONE MODES OF OPERATION......................................................31

CONTENTS
•• •
6.1 OUTDOOR AIR RESET MODE............................................................................................................31
6.1.1 Outdoor Air Temperature Sensor Installation ................................................................................................31
6.1.2 Outdoor Reset Mode Setup............................................................................................................................31
6.2 CONSTANT SETPOINT MODE ...........................................................................................................32
6.3 REMOTE SETPOINT MODE................................................................................................................33
6.4 DIRECT DRIVE MODES.......................................................................................................................33
6.5 COMBINATION CONTROL SYSTEM (CCS).......................................................................................34
6.5.1 Combination Control System Field Wiring......................................................................................................35
6.5.2 Combination Control System Setup and Startup............................................................................................35
SECTION 7. BOILER SEQUENCING TECHNOLOGY........................................................36
7.1 INTRODUCTION...................................................................................................................................36
7.1.1 Installation Notes............................................................................................................................................36
7.2 BST IMPLEMENTATION INSTRUCTION ............................................................................................37
7.2.1 BST Setup: Constant Setpoint.........................................................................................................................39
7.2.2 BST Setup: Remote Setpoint...........................................................................................................................39
7.2.3 BST Setup: Outdoor Air Temperature Reset...................................................................................................40
SECTION 8. MAINTENANCE..............................................................................................42
8.1 MAINTENANCE SCHEDULE ...............................................................................................................42
8.2 IGNITER-INJECTOR ............................................................................................................................42
8.3 FLAME DETECTOR .............................................................................................................................43
8.4 SAFETY DEVICE TESTING.................................................................................................................44
8.5 BURNER INSPECTION........................................................................................................................44
8.6 CONDENSATE DRAIN TRAP ..............................................................................................................44
8.7 AIR FILTER CLEANING AND REPLACEMENT ..................................................................................45
8.8 SHUTTING BOILER DOWN FOR EXTENDED PERIOD.....................................................................46
8.9 RETURNING THE BOILER TO SERVICE AFTER SHUTDOWN........................................................46
8.10 RECOMMENDED PERIODIC TESTING............................................................................................46
8.11 RECOMMENDED SPARES ...............................................................................................................48
SECTION 9. TROUBLESHOOTING....................................................................................49
9.1 INTRODUCTION...................................................................................................................................49
9.2 ADDITIONAL FAULTS WITHOUT SPECIFIC FAULT MESSAGES ....................................................57
SECTION 10. APPENDIX A: WIRING SCHEMATICS...........................................................59

FORWARD
•• •
FOREWORD
TheAERCOCFRBoilerutilizesabreakthroughCondensing-Prooftechnologythatmaintainsdryfluegas
while exceeding efficiency standards. It delivershigh performanceofupto86%thermalefficiency–
helping engineers, contractors and owners comply with the latest energy conservation mandates.
TheCFRBoilerachievesthisefficiencywhilesafelyreusingexistingCategoryI/TypeBventing,allowing
forcost-friendlysolutioninretrofitprojects.Witha3000MBHinput,itcanbeoperatedwithnaturalgas
and has aturndown of upto 3:1 tomatch a building’s heating loadand Low NOx emissionsdownto
20ppm NOx.
The CFR operates within the input and output ranges listed below.
CFR Boiler Input and Output Ranges
MODEL
INPUT RANGE (BTU/HR.)
GROSS OUTPUT (BTU/HR.)
MINIMUM
MAXIMUM
MAXIMUM
CFR 3000
1,000,000
3,000,000
2,580,000
The output of the boiler is a function of the unit’s firing rate (valve position) and return water
temperature.
When installedandoperatedinaccordancewiththisInstructionManual,theCFR3000complieswith
theNOxemissionstandardsoutlinedinSouthCoastAirQualityManagementDistrict(SCAQMD),Rule
1146.2.TheCFR3000complieswiththeBayAreaAirQualityManagementDistrictregulation9,Rule7.
TheCFRgas-firedboilerisafan-assisted,hydronic-heatingunitwiththefollowingventingcapabilities:
1. Room Combustion Air, Vertical Discharge
2. Ducted Combustion Air, Vertical Discharge
WARNING:Itiscriticalforsafeoperationthatthefluegasventbedesignedtopreventcondensation
in the vent. Condensation canoccurintheCFRboiler,sounitsarefittedwithacondensateremoval
trap, with an air inlet, vent connections, and condensate removal connection. With its advanced
technology, the CFR boiler delivers dry flue gas for safe exhaust into Category I venting.
Please consult the CFR Boiler Venting and Combustion Air Design Guide (TAG-0105) for a list of
allowable and preferred vent materials.
Unless otherwise specified:
● All descriptions in this document apply to the CFR Series of boiler.
● All measurements apply to natural gas models.

SECTION 1 SAFETY PRECAUTIONS
•• •
SECTION 1. SAFETY PRECAUTIONS
1.1 Warnings & Cautions
Installers andoperating personnelMUST, at alltimes, observeall safetyregulations. Thefollowing
warnings and cautions are general and must be given the same attention as specific precautions
included in these instructions. In addition to all therequirementsincluded inthis AERCO Instruction
Manual, the installation of unitsMUST conformwith local building codes,or, in the absenceoflocal
codes, ANSI Z223.1 (National Fuel Gas Code Publication No. NFPA-54) for gas-fired boilers and
ANSI/NFPASBforLPgas-firedboilers.Whereapplicable,theequipmentshallbeinstalledinaccordance
with the current Installation Code for Gas Burning Appliances and Equipment, CSA B149.1, and
applicableProvincialregulationsfortheclass,whichshouldbecarefullyfollowedinallcases.Authorities
having jurisdiction should be consulted before installations are made.
See section 1.4 forimportant informationregarding installationofunitswithin theCommonwealthof
Massachusetts.
This manual is an integral part of the product. It must be maintained in a safe place in legible
condition and given to the user by the installer for future reference.
⚠
●DoNOTunderanycircumstancesusematches,candles,flames,orothersourcesofignitiontocheckfor
gas leaks. Failure to heed this warning may result in death or serious injury.
●Fluidsunderpressuremaycauseinjurytopersonnelordamagetoequipmentwhenreleased.Besureto
shutoffallincomingandoutgoingwatershutoffvalves.Carefullydecreasealltrappedpressurestozero
before performing maintenance.
●Shut off all gas and electrical inputs to unit before performing any maintenance.
●Theexhaustventpipeoftheunitoperatesunderapositivepressureandthereforemustbecompletely
sealed to prevent leakage of combustion products into living spaces.
⚡ ⚡ ⚡ ⚡
●Electricalvoltagesupto480VACand24voltsACmaybeusedinthisequipment.Therefore,tooperate
safelythecoverontheunit’spowerbox(locatedbehindthefrontpaneldoor)mustbeinstalledatall
times, except during maintenance and servicing.
●A single-pole(120VAC units)or three-pole(220+ VAC units) switchmust beinstalled onthe unit’s
electricalsupplyline.Theswitchmustbeeasilyaccessibletoquicklydisconnectelectricalservice.Donot
affix switch to unit sheet metal enclosures.
•Manysoapsusedforgaspipeleaktestingarecorrosivetometals.Thepipingmustberinsedthoroughly
with clean water after leak checks have been completed.
•DONOTusethisboilerifanyparthasbeenunderwater.Callaqualifiedservicetechniciantoinspectand
replace any part that has been under water.

SECTION 1 SAFETY PRECAUTIONS
•• •
1.2 Emergency Shutdown
If overheating occurs or the gas supply fails to shut off,close the manual shutoff valve (Figure 1-1)
located external to the unit.
Figure 1-1: External Manual Gas Shutoff Valve
In addition,to ensure safety an emergency shutdown procedurethataddressesthefollowingpoints
must be designed and implemented at the site:
•For automatically operated unattendedboilers located ina boiler room, amanually operated
remoteshutdownswitchorcircuitbreakerlocatedjustinsideoroutsideeachboilerroomdoor.
Design the system so activation of the emergency shutdown switch or circuit breaker will
immediately shut off the fuel supply to the unit(s).
•Forautomatically operatedunattendedboilersinalocationotherthanaboilerroom,amanually
operatedremoteshutdownswitchorcircuitbreakermarkedforeasyidentificationatalocation
readily accessible in the event of boiler mis-operation.
•Design the system so activation of the emergency shutdown switch or circuit breaker will
immediately shut off the fuel.
•Forboilersmonitoredand/oroperatedfromacontinuouslyoccupiedcontrolroom,anemergency
shutdownswitchinthecontrolroomhard-wiredtoimmediatelyshutoffthefueluponactivation.
1.3 Prolonged Shutdown
In an emergency, turn off the electrical power supply to the boiler and close the manual gas valve
located upstream from the unit. The installer must identify the emergency shut-off device.
If the unit is being shut down for an extended period of time, such as a year or more, follow the
instructions in Section 8.8 : Shutting Boiler Down for Extended Period.
Whenreturninga unittoserviceafteraprolongedshutdown,followtheinstructionsinSections4and5
to verify that all system-operating parameters are correct.
NOTE: The Installer must identify and indicate the location of the
emergency shutdown manual gas valve to operating personnel.
VALVE
OPEN
VALVE
CLOSED

SECTION 1 SAFETY PRECAUTIONS
•• •
1.4 IMPORTANT –For Massachusetts Installations
•The boiler must be installed by a plumber or a gas fitter who is licensed within the
Commonwealth of Massachusetts.
•Prior to unit operation, the completegas trainandallconnections mustbeleaktested
using a non-corrosive soap.
•The vent termination must be located a minimum of 4 feet above grade level.

SECTION 2 EDGE CONTROLLER OPERATION
•• •
SECTION 2. EDGE CONTROLLER OPERATION
2.1 Introduction
ThissectionprovidesabriefoutlineofhowtogainaccesstoCFRBoiler’sEdgeControllerfunctionality.
TheEdgeControllerfrontpanelisshownbelow.Thispanel’stouchscreendisplaycontainsthecontrols,
indicators and displays necessary to operate, adjust and troubleshoot the boiler.
Figure 2-1 Edge Controller Front Panel
1
Multi-Function Bar, shows either:
•Fire Rate
•Valve Position
2
Parameter Indicator for both temperature
read-outs:
•LEFT: Inlet or Setpoint temperature
•RIGHT: Outlet or System Header
temperature
3
Temperature scale indicator: Fahrenheit or
Celsius
4
Configurable temperature read-outs (2):
•LEFT: Inlet or Setpoint temperature
•RIGHT: Outlet or System Header
temperature
5
Operation Mode Indicators (2):
•LEFT: Demand or Manual
•RIGHT: Manager or Client (BSTonly)
6
Edge Controller Touchscreen
7
Soft Keys
8
onAER Indicator Light
9
Ready Light
10
Enable/Disable Switch
11
Low Water Level Buttons (2):
•TEST: Initiates Low Water test
•RESET:ResetsunitafterLowWatertest
2
3
6
7
10
11
4
5
9
8
1

SECTION 2 EDGE CONTROLLER OPERATION
•• •
2.2 Login and Password Entry
The Edge Controller has multiple levels of password protection.
Level
Password
Description
1
No password
The default. Many parameters are visible but “Read Only.”
2
159
Allows routine maintenance by AERCO Trained Technicians (ATT).
Ahigher-levelpasswordforAERCOMasterTechnicians(AMTs)isdistributedonanindividualbasis.To
enter a password:
1. OntheEdgeController,gotoMainMenu→AdvancedSetup→Access.TheEnterPasswordscreen
appears.
2. Usethenumberkeypadtoenterthepassword(eachnumberappearsasa*),thenpressSave.You
will have access to the functionality associated with the level of the password entered.
Figure 2-2: Enter Password Screen
3. Onceyouhavesuccessfullyloggedintothesystem,theMainMenuappears.AllEdgefunctionalityis
accessed through one of the six Main Menu items.
Figure 2-3: Edge Controller Main Menu
NOTE: Full instructions for using the Edge Controller are in the Edge Controller Manual OMM-0139.

SECTION 3 START SEQUENCE
•• •
SECTION 3. START SEQUENCE
3.1 Introduction
TheinformationinthissectionprovidesaguidetostartingtheCFRBoilerusingtheEdgeController. Itis
imperative that the initial startup of this unit be performed by factory trained personnel. Operation
prior to initial startup byfactorytrained personnelmay void the equipmentwarranty. Inaddition,the
following WARNINGS and CAUTIONS must be observed at all times.
3.2 Start Sequence
WhentheEdgeControllerEnable/DisableswitchissettotheEnableposition,itchecksallpre-purgesafety
switches to ensure they are closed. These switches include:
•High Water Temperature switch
•High Gas Pressure switch
•Low Gas Pressure switch
•Low Water Level switch
•Safety Shut-Off Valve (SSOV) Proof of Closure (POC) switch
NOTE:TheBlockedInletanddownstreamBlowerProofswitchesarenotcheckedpriortostartingthepre-purge.
Ifalloftheaboveswitchesareclosed,theREADYlight(abovetheEnable/Disableswitch)willlightwhen
the switch is in the Enable position and the unit will be in the STANDBY mode.
NOTE: If any of the Pre-Purgesafetydeviceswitchesareopen, ortherequiredconditionsarenotobserved
throughout the start sequence, appropriate fault messages will be displayed.
When there is a demand for heat, the following events occur:
1. The Controller’s red DEMAND LED status indicator will light.
2. Theunitchecksallfivepre-purgesafetyswitcheslistedatthebeginningofthissection.TheEdge
Controller’signitionsequencescreenwalksyouthroughtheignitionscreensanddemonstrates(or
highlights) which switches are not met. SSOV locations are shown in Figure 3-1.
⚠
Electricalvoltagesupto480VACmaybeusedinthisequipment.Itmustbe
serviced only by factory certified service technicians.
Do not attempt to dry fire the unit. Startingtheunitwithouta fullwater
levelcanseriouslydamagetheunitandmayresultininjurytopersonnelor
property damage. This will void any warranty.
Initial startup of the unit must be performedby AERCOfactory trained
personnel.Operationpriortoinitialstartupbyfactorytrainedpersonnel
mayvoidtheequipmentwarranty.Inaddition,thefollowingwarningsand
cautions must be observed at all times.

SECTION 3 START SEQUENCE
•• •
Figure 3-1: SSOV Location (P/N 22490 shown)
3. Auxiliary Delay occurs for a configurable length of time and the Delayed Interlocks close.
4. Once all required safety device switches are closed, a purge cycle initiates and:
a. The Blower relay energizes and turns on the blower.
b. TheAir/FuelValverotatestothefull-openpurgepositionandclosesthepurgepositionswitch.
The dial on the Air/Fuel Valve will read 100 to indicate that it is full-open (100%).
c. The Fire Rate bar graph on the Controller’s front face shows 100%.
Figure 3-2: Air/Fuel Valve in Purge Position
5. Next, the Blower Proof and Blocked Inlet switchesclose (Figure 3-3).On the IgnitionSequence
screen,thePurgingindicatorturnsgreywhilepurgingisunderway(Figure3-4),andPurgeTimer
displays the purge cycle’s elapsed time in seconds.
High Pressure
Gas Switch
Low Pressure
Gas Switch

SECTION 3 START SEQUENCE
•• •
Figure 3-3: Blower Proof Switch and Blocked Inlet Switch
Figure 3-4: Ignition Sequence Screen –Purging
6. Upon completion of the purge cycle, the Controller initiates an ignition cycle, and the following
events occur:
a) The Air/FuelValverotatestothelow-fire(Ignition)positionandclosestheignitionswitch.The
DialontheAir/FuelValvewillreadbetween25 and35toindicatethatthevalveisinthelowfire
position.
b) TheSparkCleaningcyclebegins(defaultduration=7sec.)andtheIgnitionSequencescreen’s
SparkCleaningindicator(Figure3-3)turnsgrey.Thiscycleturnsontheignitiontransformerto
produceaspark(withno gas flowing)toremovemoistureandcarbonbuildupfromthespark
element. For the duration of this cycle, the Controller displays the Cleaning Igniter status
message.
c) FollowingtheSparkCleaningcycle,powerisappliedtothegasSafetyShut-offValve(SSOV).When
theSSOVindicatestheGasValveisOPEN(POC)andtheIgnitionSequencescreen’sIgnition
indicator (Figure 3-3) turns grey.

SECTION 3 START SEQUENCE
•• •
d) Ifnosparkispresent3secondsintotheignitiontrial,theControllerabortstheIgnitionCycleand
shuts down the boiler. Refer to SectionSECTION 9 in this guide for guidance if this occurs.
Figure 3-4: Air/Fuel Valve in Ignition Position
7. Upto4secondsareallowedforignitiontobedetected. Theignitioncircuitisturnedoffonesecond
after a flame is detected.
8. After 2 seconds of continuous flame, the flame strength is indicated. After 5 seconds, the Unit
Status screen appears.
9. With the unit firing properly, it will be controlled bythe temperaturecontrol circuitry. The boiler’s
fire rate or valve position (depending on which was chosen in Section 4.2.2: Front Panel
Configuration of the Edge Controller Manual, OMM-0166) will continuously display on the
Controller’s bar graph.
10. Oncedemandforheatissatisfied,theEdgeControllerwillturnofftheSSOVgasvalve. Theblower
relay will be deactivated, and the Air/Fuel Valve will be closed. Standby is displayed.
3.3 Start/Stop Levels
ThestartandstoplevelsaretheAir/FuelValvepositions(%open)thatstartandstoptheunit,basedon
load. These levels are Factory preset as follows:
TABLE 3-1: Start/Stop Levels –NATURAL GAS
Level
CFR 3000
Start Level
30%
Stop Level
25%
Ignition Position
25%
Normally, these settings do not require adjustment.
NOTE: The energy input of the boiler is not linearly related to the Air/Fuel Valve position.

SECTION 3 START SEQUENCE
•• •
3.4 Start/Stop Levels –Air/Fuel & Energy Input
The table below shows the relationship between the energy input and Air/Fuel Valve position
document.
TABLE 3-2: Air/Fuel Valve Position –NATURAL GAS
AIR/FUEL VALVE POSITION
(% OPEN)
ENERGY INPUT
(BTU/HR)
BOILER ENERGY INPUT
(% OF FULL CAPACITY)
25% (Stop Level)
502,000
17%
30%
608,000
20%
40%
969,000
32%
50%
1,371,000
46%
60%
1,794,000
60%
70%
2,192,000
73%
80%
2,448,000
82%
90%
2,692,000
90%
100%
3,000,000
100%

SECTION 4 INITIAL START-UP
•• •
SECTION 4. INITIAL START-UP
4.1 Initial Start-Up Requirements
The following are the prerequisites for the initial start-up of the CFR boiler:
•Completetheinstallation,pertheCFRBoilerInstall-StartupManual(OMM-0163)includinggas
supply piping, ventinstallationandcondensatedrainpiping. Startinga unit withouttheproper
piping, venting, or electrical systems canbe dangerous andmay void theproduct warranty.
•Set proper controls and limits (see Section 4 in the Edge Controller Manual, OMM-0139).
Initial start-up consists of the following:
•Removing the protective bag from the air filter(s)
•Combustion calibration (refer to 4.3 )
•Test safety devices (Section 5: Safety Device Testing)
Start-upmustbesuccessfullycompletedbeforeputtingtheunitintoservice.Thestart-upinstructions
belowshouldbefollowedpreciselyinordertooperatetheunitsafelyandathighthermalefficiencyand
low flue gas emissions.
Initialunitstart-upmustbeperformedbyAERCOfactorytrainedpersonnel,whoaretrainedinthestart-
up and service of CFR boilers.
AnAERCOGasFiredStartupSheet,includedwitheachCFRunit,mustbecompletedforeachunitfor
warranty validation and a copy must be returned promptly to AERCO via e-mail at:
STARTU[email protected]M.
⚠
DONOTATTEMPTTODRYFIRETHEUNIT. Startingtheunitwithoutafullwaterlevelcandamagethe
unitandmayresultininjurytopersonneland/orpropertydamage.Thissituationwillvoidanywarranty.
REMOVE THE AIR FILTER BAG BEFORE STARTING THE UNIT.
NOTE:AERCOrecommendsthattheStandbyBlowerVoltageparameterbekeptat2.00volts(thedefaultsetat
the factory) to prevent flue gas recirculation.
Tocheck,gototheController’sMainMenu→AdvancedSetup→Performance→FireControl→Operating
Control and verify that the Standby Blower Voltage parameter is set to 2.00 V.
However,individuallyventedunitsinpositivepressureboilerroomsmaysetStandbyBlowerVoltagebetween
2.00 and 0 volts to compensate.
4.2 Tools & Instruments for Combustion Calibration
4.2.1 Required Tools & Instrumentation
•DigitalCombustionAnalyzer:Oxygenaccuracyto±0.4%;CarbonMonoxide(CO)andNitrogen
Oxide (NOx) resolution to 1 PPM
•0-to-16-inch W.C. (0 to 4.0 kPa) manometer or equivalent gauge and plastic tubing
•1/4-inch NPT-to-barbed fittings for use with gas supply manometer
•Small and large flat blade screwdrivers
•Tube of silicone adhesive

SECTION 4 INITIAL START-UP
•• •
4.2.2 Installing a Gas Supply Manometer
A 16”W.C. (4.0 kPa) gas supply manometer (or gauge) is used in the following ways:
•MountedontheupstreamsideoftheSSOVtoverifythatthegassupplypressureiswithinthe
required range of 4”W.C. and 14”W.C.
•Mounted on the downstream side of the SSOV to monitor the gas pressure during the
Combustion Calibration procedure, described in Sections 4.4.1 (Natural Gas).
Figure 4-1 shows where the manometer is installed on both upstream and downstream locations.
To Install the Gas Supply Manometer:
1. Turn off the main gas supply upstream of the unit.
2. Remove the top panel and/or front panel from the boiler to access the gas train.
3. Removethe1/4”NPT plug fromtheleakdetectionballvalveontheupstreamordownstreamside
of the SSOV, as needed during testing, as shown in Figure 4-1.
4. Install an NPT-to-barbed fitting into the tapped plug port.
5. Attach one end of the plastic tubing to the barbed fitting and the other end to the manometer.
Figure 4-1: Gas Train Components and Instrument Connections
Gas Supply Manometer Installation Instructions
1. Turn off the main gas supply upstream of the unit.
2. Remove the front panel from the boiler to access the gas train.
3. Connect manometer directly to the Low and High Gas Pressure Switches (Figure 4-1).

SECTION 4 INITIAL START-UP
•• •
4.2.3 Accessing the Analyzer Probe Port
CFRunitscontaina1/4”NPT portonthesideoftheexhaustmanifold,asshowninFigure4-2.Prepare
the port for the combustion analyzer probe as follows:
1. Refer to Figure 4-1 and remove the 1/4”NPT plug from the exhaust manifold.
2. If necessary, adjust thestop on the combustion analyzer probesoitwillextendmid-wayinto the
flue gas flow. DO NOT install the probe at this time.
4.3 Combustion Calibration
All CFR models are preconfigured at the factory to use natural gas. The CFR boiler is combustion
calibratedforStandardNOxemissions(<20ppm).Thegaspressuremustbewithintherangesshownin
Table 4-2 for each model of boiler at full fire.
Recalibrationaspartofinitialstart-upisnecessaryduetochangesinthelocalaltitude,gasBTUcontent,
gassupplypipingandsupplyregulators.CombustionCalibrationTestDatasheetsareshippedwitheach
unit. These sheets must be filled out and returned to AERCO for proper Warranty Validation.
Perform the combustion calibrationprocedurebelow toprovideoptimumperformance andto keep
readjustments to a minimum.
Figure 4-2: Gas Pressure Adjustment Screw and TAC Screw Location
4.3.1 NATURAL GAS Manual Combustion Calibration
1. Ensure the Edge Controller’s Enable/Disable switch is set to Disable.
2. Openthewatersupplyandreturnvalvestotheunitandensurethatthesystempumpsarerunning.
3. Open the NATURAL GAS supply valve to the unit.
4. Turn external AC power to the unit ON.
5. OntheController,goto:MainMenu→Calibration→ManualCombustion.Ifnecessary,entera
technician level password.
6. The first Manual Combustion Calibration screen appears lists the three steps that must be
completed before continuing.

SECTION 4 INITIAL START-UP
•• •
Figure 4-3: First Manual Combustion Calibration Screen
7. Connectthegaspressuremanometertotheupstreamsideofthegastrain’sSSOV(seeSection
4.2.2)andconnecttheCombustionAnalyzerandMultimeter(perSection4.2.3)andensurethatthe
heating loop is capable of dissipating sufficient heat at full fire.
8. Verify that the incoming (upstream) gas pressure to the unit is within the allowable range.
9. Onceyouhavecompletedthepreviousstep,movethemanometer(oruseasecondaryone)tothe
downstream side of the SSOV and press Next to continue.
10. Choose the NOx requirement for this installation: None, or ≤20 PPM.
Figure 4-4: Choose NOx Requirement
11. TheCombustionCalibrationscreenprovidestwomethodstorampthevalvepositionupordown:
•Method 1: Toggle through the pre-set calibration points till you reach the desired valve
position, then press Go to go to that point (left image below).
•Method2:EnableFineVPStep,thenmanuallypressthe+ or–buttonsonceper1%tobring
the unit to the desired valve position (right image below).

SECTION 4 INITIAL START-UP
•• •
Figure 4-5: Manual Combustion Calibration Screens
12. Set the Controller’s Enable/Disable switch to Enable.
13. Change the valve position to 30%, press Go, then verify the unit has ignited.
14. Use the (Right) arrow key to change the valve position to 100%, then press Go.
15. Verify that the manifold gas pressure on the downstream side of the SSOV is within the range
shown in Table 4-1.If it isn’t,remove the brasshexnut on theSSOV actuator toaccess thegas
pressure adjustment screw (Figure 4-3). Make adjustments using a flat-tip screwdriver, slowly
rotatingthegaspressureadjustment(in1/4-turnincrements)clockwisetoincreasegaspressureor
counterclockwisetoreduceit.Theresultinggaspressurereadingonthedownstreammanometer
should fall in the range listed below.
TABLE 4-1: REFERENCE Natural Gas Manifold Gas Pressure Range @ 100% Fire Rate
Model
Manifold Gas Pressure Range @ 100% Fire
CFR 3000
2.3 ± 0.2” W.C. (0.57 ± 0.05 kPa)
16. With the valve position still at 100%, insert the combustion analyzer probe into the exhaust
manifold probeopening (see Figure 4-2a –4-2c inSection 4.2.3) andallow enoughtime for the
combustion analyzer reading to stabilize.
17. Usingacombustionanalyzer,comparetheO2valueintheTargetandReadingcolumns.Iftheydon’t
match,adjusttheBlowerVoltageuntiltheO2valueinbothcolumnsmatches,anduseeitherthe+
or –controls, or press on the field and type the value directly.
18. If adjusting blower voltage is not sufficient to get the O2Reading column to match the Target
column,repeatStep15toadjustgaspressureupordownwithintherangeshowninthetable,then
repeatStep18.ContinuerepeatingstepsuntilthegaspressureiswithintherangeinTable4-1and
the O2Reading column matches the Target column.
19. Enterthedownstreammanometer’sgaspressurereadingintheDownstreamGasPressurefield.
Note, this field appears only when Valve Position % = 100%.
20. Comparethemeasurednitrogenoxide(NOx)andcarbonmonoxide(CO)readingstotheTarget
valuesinTable4-2(shownasareferenceonly).Ifyouarenotina“NOx-limited”areaand/ordonot
have a NOx measurementinyouranalyzer,setthe O2tothevalueintheStandardNOxcolumn.
TABLE 4-2: NATURAL GAS Calibration Target Values @ 100% Valve Position
Model
O2%
NOx
CO
CFR 3000
5.0% ± 0.2%
≤20 ppm
<100 ppm

SECTION 4 INITIAL START-UP
•• •
NOTE:Theseinstructionsassumetheinletairtemperatureisbetween50°Fand100°F(10°C–37.8°C).IfNOx
readingsexceedthetarget valuesinTable4-1orTable4-3,increasetheO2levelto1%higherthantheTarget
value, then record the increased O2value on the Calibration sheet.
21. Once the O2level is within the specified range at 100%:
•EntertheFlameStrength,NOxandCOreadingsfromtheCombustionAnalyzerandmulti-
meter in the Manual Combustion Calibration screen’s Reading column.
•Enterthesamevalues,plustheO2value,ontheCombustionCalibrationDataSheetprovided.
22. LowertheValvePositiontothenextcalibrationpointusingthe(Left)arrowkey(ifusingMethod1
in step 11) or the Fine Valve Position –(Minus) key (if using Method 2).
•CFR 3000: 85%
23. Repeatsteps17,18and21atthatvalvepositionandtherestofthevalvepositionsinTablebelow
corresponding to your model. The O2, NOx and CO should stay within the ranges shown.
TABLE 4-3: NATURAL GAS Final Valve Positions
Valve Position
O2 %
NOx
CO
85%
5.0% ± 0.2%
≤ 20 ppm
<100 ppm
70%
5.0% ± 0.2%
≤ 20 ppm
<50 ppm
50%
5.5% ± 0.2%
≤ 20 ppm
<50 ppm
40%
5.5% ± 0.2%
≤ 20 ppm
<50 ppm
30%
5.5% ± 0.2%
≤ 20 ppm
<50 ppm
25%
5.5% ± 0.2%
≤ 20 ppm
<50 ppm
24. Iftheoxygenlevelatthelowestvalvepositionistoohigh,andtheBlowervoltageisattheminimum
value,youcanadjusttheTACscrew,whichisrecessedinthetopoftheAir/FuelValve(seeFigure4-
3).Rotatethescrew1/2turnclockwise(CW)toaddfuelandreducetheO2tothespecifiedlevel.
RecalibrationMUSTbeperformedagainfrom60%or50%downtothelowestvalvepositionafter
making a change to the TAC screw.
4.4 Reassembly
1. Set the Enable/Disable switch to the Disable position.
2. Disconnect AC power from the unit.
3. Shut off the gas supply to the unit.
4. RemovethemanometerandbarbedfittingsandreinstalltheNPTplugusingasuitablecompound.
5. Removethecombustionanalyzerprobefromthe1/4”venthole intheexhaustmanifoldandthen
replace the 1/4”NPT plug in the vent hole.
6. Replace all previously removed sheet metal enclosures on the unit.
4.5 Over-Temperature Limit Switches
The unit contains twoconfigurable over-temperature limitcontrols,positionedbehindtheunit’sfront
panel, under the Edge Controller: