Laars MagnaTherm MGH1600 User manual

Installation and Operation Instructions Document 1276J
H2359200J
FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualied in hot water boiler and heater installation and maintenance. Improper installation and/or operation
could create carbon monoxide gas in ue gases which could cause serious injury, property damage, or
death. Improper installation and/or operation will void the warranty.
Modulating Boiler Water Heater
Model MGH1600 Model MGV1600
1,600 MBTU/h 1,600 MBTU/h
Model MGH2000 Model MGV2000
1,999 MBTU/h 1,999 MBTU/h
Model MGH2500 Model MGV2500
2,499 MBTU/h 2,499 MBTU/h
Model MGH3000 Model MGV3000
3,000 MBTU/h 3,000 MBTU/h
Model MGH3500 Model MGV3500
3,500 MBTU/h 3,500 MBTU/h
Model MGH4000 Model MGV4000
4,000 MBTU/h 4,000 MBTU/h
Installation and
Operation Instructions for
WARNING
If the information in this manual is not
followed exactly, a re or explosion may result
causing property damage, personal injury or
loss of life.
Do not store or use gasoline or other
ammable vapors and liquids in the vicinity of
this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not
use any phone in your building.
• Immediately call your gas supplier from a
nearby phone. Follow the gas supplier's
instructions.
• If you cannot reach your gas supplier, call
the re department.
Installation and service must be performed by
a qualied installer, service agency, or gas supplier.
AVERTISSEMENT
Assurez-vous de bien suivres les instructions
données dans cette notice pour réduire au
minimum le risque d’incendie ou d’explosion
ou pour éviter tout dommage matériel, toute
blessure ou la mort.
Ne pas entreposer ni utiliser d’essence ni d’autres
vapeurs ou liquides inammables dans le voisinage
de cet appareil ou de tout autre appareil.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ:
• Ne pas tenter d’allumer d’appareils.
• Ne touchez à aucun interrupteur. Ne pas vous servir des
téléphones dansle bâtiment où vous êtes.
• Appelez immédiatement votre fournisseur de
gaz depuis un voisin. Suivez les instructions du
fournisseur.
• Si vous ne pouvez rejoindre le fournisseur de gaz,
appelez le sservice des incendies.
L’installation et l’entretien doivent être assurés par un
installateur ou un service d’entretien qualié ou par le
fournisseur de gaz.

LAARS Heating Systems
Table of Contents
i
SECTION 1 General Information
1.A Introduction.......................................................1
1.B Warranty...........................................................1
1.C ModelIdentication...........................................1
1.D Safety Notes.....................................................2
1.E Unit Overviews .................................................4
1.F Dimensions.......................................................7
1.G Unpacking and the Installation Kit....................8
SECTION 2 Locating the Unit
2.A Locating the unit...............................................9
2.B Correct Vent Distance from Outside Wall
or Roof Termination..........................................9
SECTION 3 Venting and Combustion Air
3.A General Venting.............................................. 11
3.B Combustion Air...............................................12
3.C Combustion Air From Room...........................12
3.C.1 Ducted Combustion Air...................................13
3.D Venting............................................................13
3.D.1 Common Venting............................................14
3.D.2 Venting Requirements Unique to Canada......14
3.E Locating the Vent & Comb Air Terminals........15
3.E.1 Side Wall Vent Terminal..................................15
3.E.2 Side Wall Combustion Air Terminal.................17
3.E.3 Vertical Vent Terminal.....................................17
3.E.4 Vertical Combustion Air Terminal....................17
3.E.5 Installations in the Commonwealth
of Massachusetts............................................17
3.F Common Vent Test .........................................18
3.G Outdoor Installation ........................................18
SECTION 4 Gas supply and Piping
4.A Gas Supply and Piping...................................20
SECTION 5 Water Flow Requirements
5.A Boiler Flow and Head Requirements..............22
5.B Water Heater Flow and Head Requirements..23
SECTION 6 Water Connection Boilers
6.A System Piping: ................................................
Hot Supply Connections.................................24
6.B Cold Water Make-Up......................................24
6.C Freeze Protection...........................................24
6.D Condensate Drain Trap ..................................25
6.E Suggested Piping Schematics........................25
SECTION 7 Water Connections
7.A Water Quality..................................................30
7.B Suggested Piping Schematics........................30
7.C Piping Requirements......................................30
7.E Water Flow......................................................32
7.D Condensate Drain Trap ..................................32
SECTION 8 Electrical Connections
8.A Installation Warnings ......................................33
8.B Main Power Connections................................33
8.C Pump Connections and Operation .................34
8.D Field Wiring.....................................................35
8.E Field Connections for Single Unit Installs.......36
8.F Field Connections for Lead / Lag Installs ......36
8.G Control Panel Layout......................................37
8.H Building Automation System Connections .....38
8.I Lead Lag Connections....................................39
8.J Wiring Diagrams.............................................40
8.K High Voltage Wiring Diagrams........................44
8.L Ladder Diagrams............................................51
SECTION 9 Navigating the Touchscreen
9.A The Touch Screen ..........................................58
9.B Using the Touch Screen .................................58
9.C Screen Menu Icons.........................................59
9.D VericationProcessfor
Safety Related Parameters ............................60
9.E Checking Individual Parameters.....................61
9.F ConguringParameters..................................62
9.G Setting the Date and Time..............................63
9.H CongurationMenus ......................................64
9.H.1 SystemIdentication&Access.......................64
9.H.2 CH-CentralHeatConguration.....................64
9.H.3 OutdoorResetConguration..........................64
9.H.4 DHW-DomesticHotWaterConguration .....65
9.H.5 WarmWeatherShutdownConguration ........65
9.H.6 DemandPriorityConguration .......................65
9.H.7 ModulationConguration................................65
9.H.8 PumpConguration........................................66
9.H.9 8.5.8PumpConguration...............................66
9.H.10 StatisticsConguration...................................66
9.H.11 High Limits......................................................66
9.H.12 Stack Limits....................................................66
9.H.13 Delta T Limits-.................................................66
9.H.14 Frost Protection..............................................67

MagnaTherm Boilers and Water Heaters
ii
9.H.15 Burner Control Ignition....................................67
9.H.16 SystemConguration .....................................67
9.H.17 SensorConguration......................................67
9.H.18 Lag(Slave)Conguration..............................68
9.H.19 Lead(Master)Conguration...........................71
9.I ParameterDefaultsandRanges ....................71
9.J ConguringforaGatewayControlforBAS...75
9.K VARI-PRIME®FlowControlSystem .............76
9.L CombustionSetupProcedure ........................77
SECTION 10 Initial startup Instructions
10.A FillingtheBoilerSystem .................................80
10.B InitialOperation ..............................................81
10.B.1 InitialBurnerOperation...................................81
10.B.2 CombustionSetupProcedure ........................81
10.C ShuttingDowntheUnit...................................81
10.D RestartingtheUnit..........................................81
SECTION 11 Maintenance
11.A SystemMaintenance .....................................82
11.B MaintenanceNotes.........................................82
11.B.1 Burner.............................................................82
11.B.2 ModulatingGasValve/Venturi .......................82
11.B.3 Controller........................................................83
11.B.4 SparkIgnitionElectrodes................................83
11.B.5 11.2.5FlameSensor .....................................83
11.B.6 Blower1600....................................................83
11.B.7 Blower2000-4000 ..........................................83
11.B.8 HeatExchangerTubes ...................................84
11.B.9 GasPressureSwitches ..................................84
11.B.10BatteryBackUpforDateandTime ................85
SECTION 12 Troubleshooting
12.A Lockouts,Holds,andAlerts ............................86
12.A.1 RespondingtoaLockout,Hold,orAlert.........86
12.A.2 ViewingtheLockoutandAlertHistories .........86
12.B TroubleshootingTable ....................................88
12.C DiagnosticTestsandInput/OutputIndicators .97
12.D LeadLagDiagnostics .....................................98
12.E Statistics .........................................................98
12.F Analysis ..........................................................98
12.G ControlSnapshot............................................99
12.H OperatingSequence.......................................99
SECTION 13 Replacement Parts ....................100
13.A GeneralInformation......................................100
13.B ComponentIllustrations,PartsLists,
 andPartNumbers ........................................101
13.B.1 FrameandJacketAssy,PartNumbers .......101
13.B.2 FinalAssembly,PartNumbers ....................103
13.B.3 ControlPanelAssembly,PartNumbers .......104
13.B.4 BlowerBurnerAssembly,
PartNumbers(Model1600) ........................105
13.B.5 BlowerBurnerAssembly,PartNumbers
(Model2000) ...............................................106
13.B.6 BlowerBurnerAssembly,
PartNumbers(Models2500and3000) .......107
13.B.7 BlowerBurnerAssembly,
PartNumbers(Models3500and4000) .......108
13.B.8 ACDistributionBoxAssemblies
andPartNumbers(Model1600) ..................109
13.B.9 ACDistributionBoxAssemblyand
BlowerPartNumbers(Model2000) ............. 110
13.B.10ACDistributionBoxAssemblyandBlower
PartNumbers(Models2500to4000) ...........111
13.B.11GasTrainAssembly,PartNumbers
 (Models1600,2000,2500and3000)........... 112
13.B.12GasTrainAssembly,PartNumbers
 (Models3500and4000)............................... 114
13.B.13WaterwayOutletAssembly,PartNumbers.. 116

LAARS Heating Systems

MagnaTherm Boilers and Water Heaters
Page 1
This manual includes information which will help you
to install, operate, and maintain the Laars Heating
Systems MagnaTherm. Please read this manual
completely before proceeding with the installation.
If you have any questions regarding this equipment,
please contact Laars Heating Systems, or your local
Laars representative. Experience has shown that
most operating problems are caused by improper
installation.
Primary information regarding your unit can be
found on the Rating Plate which is on the outside
face of the right-side panel.
LAARS Heating Systems MagnaTherm boilers
and volume water heaters are covered by a limited
warranty. The owner should complete the warranty
registration at
http://www.LAARS.com
ALL WARRANTY CLAIMS must be made by an
authorized LAARS Heating Systems representative.
Claims must include the serial number and model
(this information can be found on the rating plate).
All claims must also include the installation date and
name of the installer. Shipping costs are not included
in the warranty coverage.
SECTION 1 General Information
Rating Plate
Model Nomenclature
1 2 3 4 5 6 7 8 9 10 11 12 13
M G
SERIES
M G USAGE
H - HYDRONIC
V - VOLUME
WATER
SIZE
MBTU/h
1600
2000
2500
3000
3500
4000
FUEL
N - NATURAL
P - PROPANE
COUNTRY
CODE
X - USA/
CANADA
E - EXPORT*
OPTIONS CODE
X - STANDARD
J- CSD-1
ELEC SYSTEM
A - 120V, 1Ø
B - 240V, 1Ø
C - 208V, 3Ø
D - 480V, 3Ø
E - 600V, 3Ø
F - 208V, 1Ø
REVISION
1 -FIRST
2 -SECOND
ASME
X - “H” STAMP (MGH)
W -“HLW”STAMP(MGV)
*Not CSA approved
Consult the rating plate on the unit. The following
information identies the model number structure
(Model Nomenclature).
(1-2) Model Series Designation
M G = MagnaTherm
(3) Usage
H = Hydronic
V = Volume Water
(4-7) Size
1 6 0 0 = 1,600,000 BTU/hr input
2 0 0 0 = 1,999,000 BTU/hr input
2 5 0 0 = 2,499,000 BTU/hr input
3 0 0 0 = 3,000,000 BTU/hr input
3 5 0 0 = 3,500,000 BTU/hr input
4 0 0 0 = 4,000,000 BTU/hr input
(8) Fuel
N = Natural Gas
P = LP Gas
(9) Country Code
X = USA / CANADA
E - Export (CE - non CSA)
(10) Option Code
X = Standard Unit
J = CSD1 Version
(11) Electrical System
A - 120V, (Single Phase)
B - 240/220V, (Single Phase)
C - 208V, (Three Phase)
D - 480V, (Three Phase)
E - 600V, (Three Phase)
F - 208V, (Single Phase)
(12) Additional Options
X - “H” STAMP (MGH)
W - “HLW” STAMP (MGV)
(13) Revision
1 = First, 2 = Second
NOTE: Throughout the content of this manual,
the MagnaTherm will be referred to as a ‘unit’.
unit = MagnaTherm
1.A Introduction
1.B Warranty
1.C ModelIdentication
(Model Nomenclature)

LAARS Heating Systems
Page 2
WARNING
Carbon Monoxide Hazard
Improper adjustment of the burners may lead to poor
combustion quality, increasing the amount of carbon
monoxide produced. Excessive carbon monoxide
levels may lead to personal injury or death.
WARNING
This unit must be installed in accordance with the
procedures detailed in this manual, or the manufacturers
warranty will be voided. The installation must conform
to the requirements of the local jurisdiction having
authority, and, in the United States, to the latest edition
of the National Fuel Gas Code,ANSI Z223.1/NFPA54.
In Canada, the installation must conform to the latest
edition of CSAB149.1 Natural Gas and Propane Gas
Installation Code, and/or local codes. Where required
by the authority having jurisdiction, the installation of
these units must conform to the Standard for Controls
and Safety Devices forAutomatically Fired Boilers,
ANSI/ASME CSD-1. Any modi cations to the boiler, its
gas controls, or wiring may void the warranty. If  eld
conditions require modi cations, consult the factory
representative before initiating such modi cations.
WARNING
• Water temperature over 125°F (52°C) can cause
severe burns instantly or death from scalds.
• Children, disabled and
elderly are at highest
risk of being scalded.
• See instruction manual
before setting temperature
at the unit.
• Feel water before bathing
or showering.
• If this unit is used
to produce water that could scald if too hot, such
as domestic hot water use, adjust the outlet control
(limit) or use temperature limiting valves to obtain a
maximum water temperature of 125°F (52°C).
WARNING
The inlet gas pressure to the unit must not
exceed 13” W.C. (3.2kPa).
WARNING
Fire or Explosion Hazard
Improper con guration can cause fuel buildup and
explosion. Improper user operation may result in
property loss, severe physical injury, or death.
Any changes to safety-related con guration
parameters must only be done by experienced and/or
licensed burner/boiler operators and mechanics.
If any odor of gas is detected, or if the gas burner does
not appear to be functioning in a normal manner, close
the main gas shuto󰀨 valve. Do not shut o󰀨 the power
switch. Contact your heating contractor, gas company,
or factory representative.
NOTE: This unit is protected against hydronic
over-pressurization. A pressure relief valve is included
with each unit.
WARNING Indicates an imminently hazardous situation which, if not
avoided, can or will result in death or serious injury and can
or will result in catastrophic property damage.
Indicates a potentially hazardous situation which, if not avoided,
may result in moderate injury and/or property damage.
NOTE: Indicates instructions that are important to that topic but not
related to personal injury or property damage.
Safety Notes are used thoughout this manual to bring attention to the presence of hazards with various
risk levels and to o󰀨 er important information concering the life of this product. There are 3 basic types.
WARNING
CANCER AND REPRODUCTIVE HARM.
WWW.P65WARNINGS.CA.GOV.
AS REQUIRED BY THE STATE OF
CALIFORNIA PROPOSITION 65.
1
2
3
1.D Safety Notes

MagnaTherm Boilers and Water Heaters
Page 3
WARNING
Electrical Shock Hazard
Electrical shock can cause severe injury, death or
property damage. Disconnect the power supply before
beginning installation or changing the wiring to prevent
electrical shock or damage to the equipment. It may be
necessary to turn o󰀨 more than one power supply
to disconnect.
All electrical wiring is to be done in accordance with
local codes, or in the absence of local codes, with: 1)
The National Electrical CodeANSI/NFPANo. 70 - latest
Edition, or 2) CSASTD. C22.1 “Canadian Electrical Code
- Part 1.” This appliance must be electrically grounded in
accordance with these codes.
WARNING
The Repair Parts list designates parts that contain
refractory ceramic  bers (RCF). RCF has been classi ed
as a possible human carcinogen. When exposed to
temperatures above 180ºF, such as during direct  ame
contact, RCF changes into crystalline silica, a known
carcinogen. When disturbed as a result of servicing or
repair, these substances become airborne and, if inhaled,
may be hazardous to your health.
Do not remove or replace RCF parts or attempt any
service or repair work involving RCF without wearing
the following protective gear:
1. ANational Institute for Occupational Safety and
Health (NIOSH) approved respirator.
2. Long sleeved, loose  tting clothing.
3. Gloves.
4. Eye Protection.
NOTE: All installations must be made in accordance with
1)American National Standard Z223.1/NFPA54-Latest
Edition “National Fuel Gas Code” or
2) CSAB149.1 “Natural Gas and Propane Installation
Code” or in Canada reference the B149.1 latest
edition and with the requirement of the local utility or
other authorities having jurisdiction. Such applicable
requirements take precedence over the general
instructions contained herein.All electrical wiring is to
be done in accordance with the local codes, or in the
absence of local codes, with: 1) The National Electrical
CodeANSI/NFPANo. 70-latest Edition, or
2) CSASTD. C22.1 “Canadian Electrical Code - Part
1”. This appliance must be electrically grounded in
accordance with these codes.

LAARS Heating Systems
Page 4
Models 1600 / 2000
Shown with front doors and left side
panels removed.
Manual
Gas Valve
Spark
Generator
Rating Plate
(on outside
of panel)
Blower
Control Panel
On all models, the Control Panel
hinges forward for easy access to
wiring and to the heat exchanger.
Touch Screen
Heat Exchanger
Condensing
Unit
Air Intake and
Filter
Water Outlet
Water Inlet
Vent
Power Pack
Drain
Condensate
Trap
Gas Supply
Main Power
Connections
Field
Electrical
Connections
1.E Unit Overviews
The next 3 pages give a visual reference to the
basic component locations of the unit.

MagnaTherm Boilers and Water Heaters
Page 5
Blower
Models 2500 and 3000
Air Intake and
Filter
Water Outlet
Main Power
Connections
Water Inlet
Vent
Power Pack
Field
Electrical
Connections
Condensate
Trap
Heat Exchanger
Condensing Unit
Gas Supply
Manual
Gas Valve
Rating Plate.
(on outside of panel)
Touch Screen
Spark
Generator
Control Panel
Drain

LAARS Heating Systems
Page 6
Models 3500 and 4000
Manual
Gas Valve
(hidden behind main
gas valve)
Blower
Touch Screen
Air Intake and Filter
Main Power
Connections
Water Outlet
Water Inlet
Vent
Power Pack
Field
Electrical
Connections
Condensate
Trap
Heat Exchanger
Condensing Unit
Gas Supply
Rating Plate.
(on outside of panel)
Spark
Generator
Control Panel
Drain

MagnaTherm Boilers and Water Heaters
Page 7
E
F
U
B
A
VIEW
REAR
N Q S
P
M
R
L
G
H
K
J
T
FRONT
VIEWSIDE
VIEW
C D
Condensate Trap
Contact
Factory
Oponal
Flanges,
Vent
Gas
6”x3.5”
Touchscreen
Display
Air Inlet
Pressure
Relief
Valve
Water
Outlet
‘Knock-
down’
Height
Water
Inlet
H
J
Gas
Air Inlet
Model 4000
The Model 4000 varies from other sizes in the locaon of it’s Air Inlet and Gas Supply.
G K
VIEWREAR
Models 3500 and 4000 di󰀨er from the other sizes in the location of their Air Inlet and Gas Supply.
Models 3500 / 4000
Model A B C D E F G H J K L M N P Q R S T U
Vent Ø Air Inlet Ø
Inches (cm)Inches (cm)Inches (cm)
1600
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)68.4 (171) 4 (10) 39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 6 (15) 6 (15)60.8 (154)
2000
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)67.4 (171) 4 (10) 39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 8 (20) 8 (20)60.8 (154)
2500 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.4 (194)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30) 18.3 (46)14.8 (38) 6 (15) 8 (20) 8 (20) 71.0 (180)
3000 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25) 76.8 (195)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30) 18.3 (46)14.8 (38) 6 (15)10 (25)10 (25) 71.0 (180)
3500
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217) 6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)10 (25) 10 (25) 80.8 (205)
4000
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217) 6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)12 (30)12 (30) 80.8 (205)
Model A B C D E F G H J K L M N P Q R S T U
Vent Ø Air Inlet Ø
Inches (cm)Inches (cm)Inches (cm)
1600
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)68.4 (171) 4 (10) 39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 6 (15) 6 (15)60.8 (154)
2000
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)67.4 (171) 4 (10) 39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 8 (20) 8 (20)60.8 (154)
2500 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.4 (194)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30) 18.3 (46)14.8 (38) 6 (15) 8 (20) 8 (20) 71.0 (180)
3000 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25) 76.8 (195)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30) 18.3 (46)14.8 (38) 6 (15)10 (25)10 (25) 71.0 (180)
3500
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217) 6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)10 (25) 10 (25) 80.8 (205)
4000
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217) 6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)12 (30)12 (30) 80.8 (205)
Model A B C D E F G H J K L M N P Q R S T U
Vent Ø Air Inlet Ø
Inches (cm)Inches (cm)Inches (cm)
1600
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)68.4 (171)4 (10)39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 6 (15) 6 (15)60.8 (154)
2000
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)67.4 (171)4 (10)39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 8 (20) 8 (20)60.8 (154)
2500 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.4 (194)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30)18.3 (46)14.8 (38) 6 (15) 8 (20) 8 (20) 71.0 (180)
3000 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.8 (195)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30) 18.3 (46) 14.8 (38) 6 (15)10 (25)10 (25) 71.0 (180)
3500
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217)6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)10 (25) 10 (25) 80.8 (205)
4000
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217)6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)12 (30)12 (30) 80.8 (205)
Model A B C D E F G H J K L M N P Q R S T U
Vent Ø Air Inlet Ø
Inches (cm)Inches (cm)Inches (cm)
1600
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)68.4 (171)4 (10)39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 6 (15) 6 (15)60.8 (154)
2000
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)67.4 (171)4 (10)39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33) 6.3 (16) 8 (20) 8 (20)60.8 (154)
2500 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.4 (194)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30)18.3 (46)14.8 (38) 6 (15) 8 (20) 8 (20) 71.0 (180)
3000 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.8 (195)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69) 11.8 (30) 18.3 (46)14.8 (38) 6 (15)10 (25)10 (25) 71.0 (180)
3500
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217)6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)10 (25) 10 (25) 80.8 (205)
4000
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217)6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44) 6.7 (17)12 (30)12 (30) 80.8 (205)
Model A B C D E F G H J K L M N P Q R S T U
Vent Ø Air Inlet Ø
Inches (cm)Inches (cm)Inches (cm)
1600
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)68.4 (171)4 (10)39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33)6.3 (16)6 (15)6 (15)60.8 (154)
2000
29.3 (75)79.8 (203)38 (96)57.5 (147)49.8 (126)4.8 (12)60.8 (154)2.6 (7)8.4 (21)67.4 (171)4 (10)39.2 (100)30.4 (77)16 (41)23 (58)10.2 (26)14 (36)13 (33)6.3 (16)8 (20)8 (20)60.8 (154)
2500 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.4 (194)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69)11.8 (30)18.3 (46)14.8 (38)6 (15)8 (20)8 (20)71.0 (180)
3000 30.8 (78) 87 (221)41.5 (105)60.5 (154)60.8 (154)6.5 (16)71 (180) 4 (10) 9.8 (25)76.8 (195)4.3 (11)44.4 (113)34.5 (88)17.7 (45)27.2 (69)11.8 (30)18.3 (46)14.8 (38)6 (15)10 (25)10 (25)71.0 (180)
3500
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217)6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44)6.7 (17)10 (25) 10 (25) 80.8 (205)
4000
34.5 (88)97 (246)52 (133)70 (178)60.8 (154)6.4 (16)80.8 (205)28.8 (73) 26.5 (67) 85.6 (217)6.5 (16)51.3 (130)40 (102)21.6 (55)30.7 (78)13 (33)16 (41)17.4 (44)6.7 (17)12 (30)12 (30)80.8 (205)
'Knock-
down'
Height
Model Size Water Gas
Condensate
Connection Connection Line
1600
3" Groove Lock (or flange)
2" NPT 1"
2000
3" Groove Lock
(or flange)
2" NPT 1"
2500 3" Groove Lock
(or flange)
2" NPT 1"
3000 3" Groove Lock
(or flange)
2" NPT 1"
3500
4" Groove Lock (or flange)
2" NPT 1"
4000
4" Groove Lock
(or flange)
2" NPT 1"
1.F Dimensions
Figure 1. Dimensions

LAARS Heating Systems
Page 8
1.G Unpacking and the Installation Kit
This unit is shipped in a single crate. Carefully
disassemble the crate and inspect the unit for any
damage during shipping. Included in the crate and yet
outside of the unit is the ‘Installation Kit’ box.
Inspect the contents of the the Installation Kit box,
making sure that all parts are there and not damaged
during shipping.
1. Gromet, Nylon.
2. Box containing Outdoor Sensor
3. Box containing System Sensor
4. Tank Sensor
5. Spring Clip (used to hold tank sensor in sensor well)
12
3
4
5
6
7
6. Condensate Trap Assembly (some assembly
required) and document 4312 Condensate Trap
Assembly Instructions.
7. Installation Instructions for Sensors.
NOTE: A condensate neutralizer is NOT included.
Figure 2. The Installation Kit

MagnaTherm Boilers and Water Heaters
Page 9
NOTE : When located on the same wall, the
combustion air intake terminal must be installed a
minimum of 12” (30cm) below the exhaust terminal.
There must also be a minimum horizontal distance
from intake to the exhaust terminal of 84” (213cm)
See Figure 7
NOTE : The unit shall be installed such that the
gas ignition system components are protected
from water (dripping, spraying, rain, etc.) during
operation and service (circulator replacement,
control replacement, etc.).
SECTION 2 Locating the Unit
2.A Locating the unit
This unit may be installed indoors or outdoors. If
installing outdoors in a location that may experience
freezing temperatures, precautions must be taken to
prevent water in the heat exchanger and condensate
inside and outside of the boiler from freezing. Damage
due to freezing water or condensate is not covered by
the warranty.
Choose a location for the unit which allows
clearances on all sides for maintenance and
inspection. See Table 1. Always install the unit on a
rm, level surface. It is recommended that the unit is
installed on a raised 4” pad so that there is elevation for
a condensate neutralizer kit (not included with unit).
The unit should not be located in an area where
leakage of any connections will result in damage to
the area adjacent to the appliance, or to lower oors
of the structure.
When this type of location is not available, install a
suitable drain pan, adequately drained, under the
appliance.
The appliance is design-certied by CSA-
International for installation on combustible ooring;
in basements; in utility rooms or alcoves. Boilers
must never be installed on carpeting. The location
for the appliance should be chosen with regard to
the vent pipe lengths and external plumbing.
The unit shall be installed such that the gas ignition
system components are protected from water
(dripping, spraying, rain, etc.) during operation and
service (circulator replacement, control replacement,
etc.).
When vented vertically, the unit must be located as
close as practical to the vertical section of the vent.
If the vent terminal and/or combustion air terminal
terminate through a wall, and there is potential for
snow accumulation in the local area, both terminals
should be installed at an appropriate level above
grade or the maximum expected snow line.
The dimensions and requirements that are shown in
Table 1. should be met when choosing the locations
for the appliance.
2.B Correct Vent Distance from
Outside Wall or Roof Termination
The forced draft combustion air blower in the
appliance has su󰀩cient power to vent properly when
the guidelines in Table 3 are followed.
WARNING
If installing outdoors in a location that may
experience freezing temperatures, provisions
must be made to protect the unit from freeze
damage. Manufacturer does not warranty
damage caused by freezing temperatures.

LAARS Heating Systems
Page 10
24”
See Table 1 for Suggested Service Top
Clearances
24”
8”
8”
INTAKE / EXHAUST
MAX EQUIVALENT
SIZE DIAMETER FT. M
1600 6” 100 30
2000 & 2500 8” 100 30
3000 & 3500 10” 100 30
4000 12” 100 30
Combustion Intake and Vent must be the same size.
Installations in the U.S. require exhaust vent pipe that is CPVC
complying with ANSI/ASTM D1785 F441, polypropylene
complying with ULC S636, or stainless steel complying with
UL1738. Installations in Canada require exhaust vent pipe that
is certied to ULC S636.
Intake (air) pipe must be PVC or CPVC that complies with
ANSI/ASTM D1785 F441, ABS that complies with ANSI/ASTM
D1527, stainless steel, or galvanized material.
To calculate max equivalent length, measure the linear feet of
the pipe, and add 5 feet (1.5 m) for each elbow used.
Figure 3. Suggested Service Clearances
SURFACE INCHES CM
Front 24 61
Left Side 820
Right Side 820
Back 24 61
Top, 1600 & 2000 12 30
Top, 2500 & 3000 15 38
Top, 4000 24 61
Table 1. Suggested Service Clearances
Table 2. Required Clearances
SURFACE INCHES CM
Front 18 46
Left Side 410
Right Side 410
Back 11 28
Top 12.5
Vent 12.5
Table 3. Vent / Air Pipe Sizes

MagnaTherm Boilers and Water Heaters
Page 11
Table 4. Allowable Single Wall Stainless Steel Vent Suppliers and Part Numbers
Table 5. Allowable Polypropylene Vent Manufacturers / Trade Names
General Venng
This product requires a special venng system. Refer to venng supplier’s instrucons for complete parts list and method
of installaon. The manufacturers and product lines listed on the following tables have beentested and authorized to
safely operate with this equipment. Suppliers of stainless steel and polypropylene venng that are not listed on these
tables are not permied for use with vent category III/ IV products.
Do not mix venng suppliers and models in venng systems. Failure to comply could result in personal injury, property
damage, or death.
Installaons must comply with applicable naonal, state and local codes.
NOTE: “x”, “xx”, and “xxxx” refer to variaons in nominal size. See manufacturer’s catalog for a parcular applicaon.
ALLOWABLE SINGLE WALL STAINLESS STEEL VENT SUPPLIERS AND PART NUMBERS
Selkirk DuraVent NovaFlex
Safe-T Vent EZ Seal FasNSeal Z Flex
90° Elbow 9x14 FSELB90xx 2SVEExx90
Pipe 9x07 FSVLxxxx 2SVEPxxxx
Boiler Adapter 5x01BOI FSAAUx 2SVSAxx (OD)
2SVSTTAxx (ID)
Horizontal Terminaon (bird screen) 9x92 FSBSx 2SVSTPXxx
Vercal Terminaon (rain cap) 5X00CI FSRCx 2SVSRCxx
Inlet Air Terminaon 9xTERM FSAIHXX* 2SVSTEXxx90
FSA-xxFNSM-xPVCF
Adapter SS to PP FSAAUx-xPP 2ZDCPVCx**
*4", 6" & 7" only **up to 6"
MFR MODEL NUMBER (ABBREVIATED)
Example Components
Trade Name / Model
ALLOWABLE POLYPROPYLENE VENT MANUFACTURERS / TRADE NAMES
CentroTherm DuraVent Selkirk NovaFlex
InnoFlue PolyPro PolyFlue Z-Dens
Single Wall Pipe ISVLxxxx xPPS-x 83x002 ZDPx
Elbow ISELxxxx xPPS-E90L83x08 2ZDEx87
PVC Adapter ISAMGTxxxxxPPS-ADL (to 4")
xPPS-xxPVCM-xPPF (>4") 83x040 2ZDCPVCx
Horizontal Terminaon (bird screen)
IASPPxx (2" - 4")
IASSSxx (5" - 12")
xPPS-BG (2" - 6") 83x050 2ZDESx
Vercal Terminaon
IASPPxx (2" - 4")
IASSSxx (5" - 12")
xPPS-VKL (<5")
xPPS-VTML (5"-8")
83x050 2ZDESx
Air Inlet 2ZDESx
MFR MODEL NUMBER (ABBREVIATED)
Trade Name / Model
Example Components
General Venng
This product requires a special venng system. Refer to venng supplier’s instrucons for complete parts list and method
of installaon. The manufacturers and product lines listed on the following tables have beentested and authorized to
safely operate with this equipment. Suppliers of stainless steel and polypropylene venng that are not listed on these
tables are not permied for use with vent category III/ IV products.
Do not mix venng suppliers and models in venng systems. Failure to comply could result in personal injury, property
damage, or death.
Installaons must comply with applicable naonal, state and local codes.
NOTE: “x”, “xx”, and “xxxx” refer to variaons in nominal size. See manufacturer’s catalog for a parcular applicaon.
ALLOWABLE SINGLE WALL STAINLESS STEEL VENT SUPPLIERS AND PART NUMBERS
Selkirk DuraVent NovaFlex
Safe-T Vent EZ Seal FasNSeal Z Flex
90° Elbow 9x14 FSELB90xx 2SVEExx90
Pipe 9x07 FSVLxxxx 2SVEPxxxx
Boiler Adapter 5x01BOI FSAAUx 2SVSAxx (OD)
2SVSTTAxx (ID)
Horizontal Terminaon (bird screen) 9x92 FSBSx 2SVSTPXxx
Vercal Terminaon (rain cap) 5X00CI FSRCx 2SVSRCxx
Inlet Air Terminaon 9xTERM FSAIHXX* 2SVSTEXxx90
FSA-xxFNSM-xPVCF
Adapter SS to PP FSAAUx-xPP 2ZDCPVCx**
*4", 6" & 7" only **up to 6"
MFR MODEL NUMBER (ABBREVIATED)
Example Components
Trade Name / Model
ALLOWABLE POLYPROPYLENE VENT MANUFACTURERS / TRADE NAMES
CentroTherm DuraVent Selkirk NovaFlex
InnoFlue PolyPro PolyFlue Z-Dens
Single Wall Pipe ISVLxxxx xPPS-x 83x002 ZDPx
Elbow ISELxxxx xPPS-E90L83x08 2ZDEx87
PVC Adapter ISAMGTxxxxxPPS-ADL (to 4")
xPPS-xxPVCM-xPPF (>4") 83x040 2ZDCPVCx
Horizontal Terminaon (bird screen)
IASPPxx (2" - 4")
IASSSxx (5" - 12")
xPPS-BG (2" - 6") 83x050 2ZDESx
Vercal Terminaon
IASPPxx (2" - 4")
IASSSxx (5" - 12")
xPPS-VKL (<5")
xPPS-VTML (5"-8")
83x050 2ZDESx
Air Inlet 2ZDESx
MFR MODEL NUMBER (ABBREVIATED)
Trade Name / Model
Example Components
Manufacturer Model Numbers (abreviated)
Manufacturer Model Numbers (abreviated)
SECTION 3 Venting and Combustion Air
3.A General Venting
This unit requires a special venting system. Refer
to venting supplier’s instructions for complete parts
list and method of installation. The manufacturers
and product lines listed on the following tables have
been tested and authorized to safely operate with
this equipment. Suppliers of stainless steel and
polypropylene venting that are not listed on these
tables are not permitted for use with vent category
III & IV products.
Do not mix venting suppliers and models in venting
systems. Failure to comply could result in personal
injury, property damage, or death.
Installations must comply with applicable national,
state and local codes.

LAARS Heating Systems
Page 12
shall communicate directly, or by ducts, with the
outdoors or spaces that freely communicate with
the outdoors. When directly communicating with the
outdoors, or when communicating to the outdoors
through vertical ducts, each opening shall have a
minimum free area of 1 square inch per 4000 Btu/
hr (550 square mm/kW) of total input rating of all
equipment in the enclosure. When communicating
to the outdoors through horizontal ducts, each
opening shall have a minimum free area of not less
than 1square inch per 2000 Btu/hr (1100 square
mm/kW) of total input rating of all equipment in the
enclosure.
Method 2: One permanent opening, commencing
within 12” (300 mm) of the top of the enclosure,
shall be permitted. The opening shall directly
communicate with the outdoors or shall
communicate through a vertical or horizontal duct
to the outdoors or spaces that directly communicate
with the outdoors and shall have a minimum free
area of 1square inch per 3000 Btu/hr (734 square
mm/kW) of the total input rating of all equipment
located in the enclosure. This opening must not be
less than the sum of the areas of all vent connectors
in the conned space.
3.B Combustion Air
Boilers and water heaters must have provisions for
combustion and ventilation air in accordance with the
applicable requirements for Combustion Air Supply
and Ventilation in the National Fuel Gas Code, ANSI
Z223 1; or in Canada, the Natural Gas and Propane
Installation Code, CSA B149.1. All applicable
provisions of local building codes must also be
adhered to.
This unit can take combustion air from the space
in which it is installed, or the combustion air can
be ducted directly to the unit. Ventilation air must
be provided in either case.
3.C Combustion Air From Room
In the United States, the most common requirements
specify that the space shall communicate with the
outdoors in accordance with Method 1 or 2. (See the
following descriptions.) Where ducts are used, they
shall be of the same cross-sectional area as the free
area of the openings to which they connect.
Method 1: Two permanent openings, one
commencing within 12” (300 mm) of the top and
one commencing within 12” (300 mm) of the bottom,
of the enclosure shall be provided. The openings
Table 6. Ducted Air Accessories
(Place in section 3.1)
Model 1600 Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Screen for horizontal galvanized air pipe D2012104 D2012101 D2012101 D2012102 D2012103 D2012103
Screen for horizontal PVC air pipe CA012004 CA012001 CA012001 CA012002 CA012003 CA012003
Screen for horizontal polypropylene air pipe CA012204 CA012201 CA012201 CA012202 CA012203 CA012203
Screen for vertical galvanized air pipe D2012204 D2012201 D2012201 D2012202 D2012203 D2012203
Screen for vertical PVC air pipe CA012404 CA012401 CA012401 CA012402 CA012403 CA012403
Screen for vertical polypropylene air pipe CA012604 CA012601 CA012601 CA012602 CA012603 CA012603
Table 3a - Ducted Air Accessories
(Place in section 3.2)
Model 1600 Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Horizontal vent terminal for stainless steel D2012004 D2012001 D2012001 D2012002 D2012003 D2012003
Screen for horizontal CPVC vent CA012104 CA012101 CA012101 CA012102 CA012103 CA012103
Screen for vertical stainless steel vent D2012304 D2012301 D2012301 D2012302 D2012303 D2012303
Screen for vertical CPVC vent CA012504 CA012501 CA012501 CA012502 CA012503 CA012503
Table 3* - Vent Accessories
(Place in section 3.5)
Model 1600 Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Air intake screen for unit placed outdoors CA0011904 CA011901 CA011901 CA011902 CA0011903 CA0011903
Vent terminal for unit placed outdoors CA011803 CA011801 CA011801 CA011802 CA011803 CA011803
Table 3** - Air & Vent Accessories for Units Placed Outdoors
Table 7. Required Combustion Air Pipe Material
Material United States Canada
ABS ANSI/ASTM D1527 The air pipe material must be chosen based upon
the intended application of the boiler or water
heater, and must be installed according to the vent
manufacturer’s installation instructions.
PVC, sch. 40 ANSI/ASTM D1785 or D2665
CPVC, sch. 40 ANSI/ASTM F441
Single wall galv. steel 26 gauge
Polypropylene ULC S636 Class 2C

MagnaTherm Boilers and Water Heaters
Page 13
Other methods of introducing combustion and
ventilation air are acceptable, providing they conform
to the requirements in the applicable codes listed
above.
In Canada, consult local building and safety codes
or, in absence of such requirements, follow CAN/
CSA B149.
3.C.1 Ducted Combustion Air
The combustion air can be taken through the
wall, or through the roof. The manufacturer o󰀨ers
accessories to use with ducted air systems, as
shown in Table 6.
See Table 7 to select the appropriate diameter air
pipe. When taken from the roof, a eld-supplied
rain cap or an elbow arrangement must be used to
prevent entry of rain water. (See Figure 8).
Use ABS, PVC, CPVC, polypropylene, stainless
steel, or galvanized pipe for the combustion air
intake (See Table 7). The intake must be sized per
Table 3. Route the intake to the boiler as directly
as possible. Seal all joints. Provide adequate
hangers. The unit must not support the weight of the
combustion air intake pipe. The maximum equivalent
pipe length allowed is 100 feet (30 m).
Each elbow is considered to be 5 feet (1.5m)
When using polypropylene or stainless steel
materials in horizontal duct congurations, a single
elbow must be installed on the end of the air inlet
to act as an outdoor terminal. In vertical duct
applications, two elbows must be installed on the
end of the inlet to act as a vent terminal. When
elbows are use as terminals, appropriate screens
must be installed to prevent blockage.
The elbow(s) required for termination are not
included in the kits sown in Table 6
The connection for the intake air pipe is on the back
panel.
In addition to air needed for
combustion, air shall also
be supplied for ventilation,
including air required for
comfort and proper working
conditions for personnel.
Refer to the applicable
codes.
3.D Venting
WARNING
Selection of improper vent materials for
installations that are installed in closets, or will be
operated in high ambient temperature levels, may
lead to property damage, personal injury, or death.
WARNING
Failure to use the appropriate vent material,
installation techniques, or glues and sealants
could lead to vent failure causing property
damage, personal injury or death.
WARNING
Use of cellular core PVC (ASTM F891), cellular
core CPVC, or Radel® (polyphenolsulfone) in
non-metallic venting systems is prohibited and that
covering non-metallic vent pipe and ttings with
thermal insulation is prohibited.
WARNING
All venting must be installed according to this
manual and any other applicable local codes,
including but not limited to, ANSI Z223.1/NFPA54,
CSA B149.1, CSAB149.2 and ULC S636. Failure
to follow this manual and applicable codes may
lead to property damage, severe injury, or death.
If the system temperatures are unknown at the
time of installation, class IIC or higher venting
material is recommended.
This unit is a Category II and IV appliance and
may be installed with vent materials meeting the
standards listed on Table 10.
The units vent can terminate through the roof, or
through an outside wall.
Table 8. Vent Sizing for Category II - Gravity Vent
Table 2 –Vent Sizing for Category II –gravity vent
Boiler Model
Vent Connection Size Diameter
(provided with boiler)
Vent Connector Size Diameter
(Increaser*)
MGH/V1600
6”
14”
MGH/V2000
8”
14”
MGH/V2500
8”
18”
MGH/V3000
10”
18”
MGH/V3500
10”
22”
MGH/V4000
12
22”
WARNING: Vent must be installed with appropriate condensate traps and using only specific
manufacturers, models and materials outlined in this manual.
Draft must always remain between -0.1” and -0.001” at all firing rates. If pressures outside of
this range are measured, consult professional venting engineer for recommendations, such as
double-acting barometric dampers to avoid reduced performance or hazardous conditions.

LAARS Heating Systems
Page 14
All installations must be done following the vent
supplier’s recommended installation techniques. If
these are not available, refer to the Manufacturer
recommendations for the material used.
NOTE: For Category II and IV boilers, the
horizontal runs must be sloping upwards not less
than 1/4 inch per foot (21 mm/m) from the boiler to
the vent terminal, so as to prevent accumulation
of condensate and, where necessary, have the
means provided for drainage of condensate.
ATTENTION: Pour la catégorie II & IV, les
chaudières ont horizontal en pente vers le haut au
moins 1/4 de pouce par pied (21 mm/m) à partir
de la chaudière pour l’évent borne; être installé
de façon à éviter l’accumulation de condensats;
et, le cas échéant, ont des moyens prévus pour
l’évacuation des condensats.
The venting must be correct to allow the condensate
to run back to the unit to drain. Route the vent pipe
to the heater as directly as possible. Seal all joints.
Provide adequate hangers as required in the venting
system manufacturer’s Installation Instructions, or at
least every 4 feet.
The unit must not support the weight of the vent
pipe. The maximum equivalent pipe length
allowed is 100 feet (30m). Each elbow is
considered to be 5 feet (1.5m). The manufacturer
o󰀨ers accessory kits to use with horizontal and
vertical exhaust vent systems, as shown in Table 9
3.D.1 Common Venting
This unit can be common vented, however, the
common venting must be a professionally designed
and approved system. See Document 1396.
pdf Application Guide for Common Venting
(commercial condensing), available online.
Catagory II and IV units are never permitted to
share a vent with any Catagory 1 appliances.
3.D.2 Venting Requirements Unique to
Canada
These high e󰀩ciency boilers and water heaters
are Vent Category II and IV appliances. Per the
requirements of CAN/CSA-B149.1, only BH vent
systems can be connected to these units and
such vent systems, either ULC S636 certied
stainless steel or other ULC S636 certied BH
vent (eg. plastics) must be installed per the vent
manufacturer’s certied installation instructions.
It is the responsibility of the appropriately
licensed technician installing this unit to use ULC
S636 certied vent material consistent with the
requirements as described in the Venting and
Combustion Air section.
Class I venting systems are suitable for gas-red
appliances producing ue gas temperature of more
than 135°C, but not more than 245°C.
Class II venting systems are suitable for gas-red
appliances producing ue gas temperatures of
135°C or less.
Table 9. Vent Accessory Kits
(Place in section 3.1)
Model 1600 Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Screen for horizontal galvanized air pipe D2012104 D2012101 D2012101 D2012102 D2012103 D2012103
Screen for horizontal PVC air pipe CA012004 CA012001 CA012001 CA012002 CA012003 CA012003
Screen for horizontal polypropylene air pipe CA012204 CA012201 CA012201 CA012202 CA012203 CA012203
Screen for vertical galvanized air pipe D2012204 D2012201 D2012201 D2012202 D2012203 D2012203
Screen for vertical PVC air pipe CA012404 CA012401 CA012401 CA012402 CA012403 CA012403
Screen for vertical polypropylene air pipe CA012604 CA012601 CA012601 CA012602 CA012603 CA012603
Table 3a - Ducted Air Accessories
(Place in section 3.2)
Model 1600 Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Horizontal vent terminal for stainless steel D2012004 D2012001 D2012001 D2012002 D2012003 D2012003
Screen for horizontal CPVC vent CA012104 CA012101 CA012101 CA012102 CA012103 CA012103
Screen for vertical stainless steel vent D2012304 D2012301 D2012301 D2012302 D2012303 D2012303
Screen for vertical CPVC vent CA012504 CA012501 CA012501 CA012502 CA012503 CA012503
Table 3* - Vent Accessories
(Place in section 3.5)
Model 1600 Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Air intake screen for unit placed outdoors CA0011904 CA011901 CA011901 CA011902 CA0011903 CA0011903
Vent terminal for unit placed outdoors CA011803 CA011801 CA011801 CA011802 CA011803 CA011803
Table 3** - Air & Vent Accessories for Units Placed Outdoors
Installation Standards
Material United States Canada
Stainless steel UL 1738 Venting must be ULC S636 certied for use as
venting material. The venting material class must
be chosen based upon the intended application
of the unit, and must be installed according to
the maximum ue gas temperature and the vent
manufacturer’s instructions.
CPVC, sch 40 ANSI/ASTM F441
Polypropylene ULC S636 Class 2C
Table 10. Required Exhaust Vent Material

MagnaTherm Boilers and Water Heaters
Page 15
Class II venting systems are further classied into
four temperature ratings as follows:
A Up to and including 65°C / 149°F
B Up to and including 90°C / 194°F
C Up to and including 110°C / 230°F and
D Up to and including 135°C / 275°F
Flue Gas Sampling Port -
It is also the responsibility of the installer to ensure
that a ue gas sampling port is installed in the vent
system. This ue gas sampling port must be installed
near the ue connection of the unit: within 2 feet of
the ue connection. There is no ue gas sampling
port internal to the unit, so one must be installed
in the vent system external to the unit. A ue gas
sampling port available as a component of the ULC
S636 certied vent system is preferred. However, if
one is not available with the certied vent system,
Manufacturer suggests using a tee with the branch
connection sized to allow for insertion of a ue gas
analyzer probe. The branch connection must be
resealable with a cap or other means to ensure the
vent system remains sealed. (See Figure 4)
Consideration must be given to the placement and
orientation of the ue gas sampling port to ensure
that condensate is free to ow back into the unit and
not collect anywhere in the vent system - including in
the ue gas sampling port.
Exhaust Vent Terminal -
An exhaust vent terminal must be installed. If an
exhaust vent terminal is not available with the
certied vent system, the manufacturer suggests
the use of a coupler tting from the certied vent
system into which the vent terminal screen can be
installed. Be sure to install and terminate both vent
and combustion air pipes per the instructions in this
section.
3.E Locating the Vent and Combustion
Air Terminals
3.E.1 Side Wall Vent Terminal
The appropriate side wall vent terminal must be
used. The terminal must be located in accordance
with ANSI Z223.1/NFPA54 and applicable local
codes. In Canada, the installation must be in
accordance with CSA B149.1 or .2 and local
applicable codes.
Consider the following when installing the terminal:
1. Figure 7 on page 17 shows the requirements
for mechanical vent terminal clearances for the
U.S. and Canada.
2. Vent terminals for condensing appliances or
appliances with condensing vents are not
permitted to terminate above a public walkway,
or over an area where condensate or vapor
could create a nuisance or hazard.
3. Locate the vent terminal so that vent gases
cannot be drawn into air conditioning system
inlets.
4. Locate the vent terminal so that vent gases
cannot enter the building through doors,
windows, gravity inlets or other openings.
Whenever possible, avoid locations under
windows or near doors.
5. Locate the vent terminal so that it cannot
be blocked by snow. The installer may
determine that a vent terminal must be
higher than the minimum shown in codes,
depending upon local conditions.
6. Locate the terminal so the vent exhaust
does not settle on building surfaces or other
nearby objects. Vent exhaust bi-products may
damage surfaces or objects.
7. If the boiler or water heater uses ducted
combustion air from an intake terminal located
on the same wall, see See Figure 6 and Figure
7 for proper spacing and orientation.
Figure 4. Test Port

LAARS Heating Systems
Page 16
*When vent terminal is less than 10 feet (3 m) horizontally
from a forced air inlet, the terminal must be at least 3 feet
(0.9 m) above the air inlet. (US only)
Figure 5. Combustion Air and Vent Through Side Wall
U.S. Installations (see note 1) Canadian Installations (see note 2)
A= Clearance above grade, veranda, porch, 12 inches (30 cm) 12 inches (30 cm)
deck, or balcony See note 6 See note 6
B= Clearance to window or door that may be Direct vent only: 12 inches (30 cm); 36 inches (91 cm)
opened Other than Direct vent: 4 ft (1.2m) below or to
side of opening; 1 ft (30 cm) above opening
C= Clearance to permanently closed window See note 4 See note 5
D= Vertical clearance to ventilated so󰀩t located
above the terminal within a horizontal See note 4 See note 5
distance of 2 feet (61 cm) from the center
line of the terminal
E= Clearance to unventilated so󰀩t See note 4 See note 5
F= Clearance to outside corner See note 4 See note 5
G= Clearance to inside corner See note 4 See note 5
H= Clearance to each side of center line 3 feet (91 cm) within a height 15 feet
extended above meter/regulator assembly See note 4 above the meter/regulator assembly
I= Clearance to service regulator vent outlet See note 4 3 feet (91 cm)
J= Clearance to nonmechanical air supply Direct vent only: 36” (91cm)
inlet to building or the combustion air inlet Other than Direct vent: 4 ft (1.2m) below 36 inches (91 cm)
to any other appliance or to side of opening; 1 ft (30 cm) above opening
K= Clearance to a mechanical air supply inlet 3 feet (91 cm) above if within 10 feet (3 m) 6 feet (1.83 m)
horizontally
L= Clearance above paved sidewalk or paved Vent termination not allowed in this location 7 ft (2.1 m)
driveway located on public property for category IV appliances. See note 5
M= Clearance under veranda, porch, deck, See note 4 12 inches (30 cm)
or balcony See note 5
Notes:
1. In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Gas Code.
2. In accordance with the current CAN/CSA-B149 Installation Codes.
3. Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the oor.
4. For clearances not specied in ANSI Z223.1 / NFPA 54, clearance is in accordance with local installation codes and the
requirements of the gas supplier.
5. For clearances not specied in CAN/CSA-B149, clearance is in accordance with local installation codes and the requirements of the
gas supplier.
6. IMPORTANT: All terminals must be placed so that they remain a minimum 12” above expected snow line. Local codes may have
more specic requirements, and must be consulted.