Laars Neotherm NTH Owner's manual

Installation and
Operation Instructions for
Modulating Boilers and
Volume Water Heaters
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.
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.
with Touchscreen
Indoor and Outdoor
NTH Sizes 399 – 850 MBTU/h
NTV Sizes 150 – 850 MBTU/h
®
H2374100J
Installation and Operation Instructions Document 1330J

Table of Contents
i
LAARS Heating Systems
SECTION 1
GENERAL INFORMATION
1.A Introduction ....................................................... 5
1.B Warranty ........................................................... 5
1.C Model Identication ........................................... 5
1.D Safety Notes ..................................................... 6
1.E Model Overview ............................................... 8
1.F Dimensions, Indoor Models ............................ 14
1.G Dimensions, Outdoor Models ......................... 16
1.H The Installation Kit (installation parts box). .... 18
SECTION 2
LOCATING THE UNIT
2.A General Information ........................................ 20
2.B Locating Appliance for Correct Vent Distance
from Outside Wall or Roof Termination ........... 20
SECTION 3
VENTING AND COMBUSTION AIR
3.A General Venting .............................................. 21
3.B Combustion Air ............................................... 21
3.C Venting ............................................................ 24
3.D Common Venting ............................................ 26
3.E Locating Vent and Combustion Air Terminals . 26
3.F Common Vent Test ......................................... 30
SECTION 4
GAS SUPPLY AND PIPING
............................. 31
SECTION 5
PUMP REQUIREMENTS
5.A Boiler Flow and Head Requirements - Boiler . 32
5.B Water Heater Flow and
Head Requirements - Heater .......................... 32
SECTION 6
WATER CONNECTIONS
6.A Boiler.....................................................34
6.A.1 Boiler Water Piping ........................................ 34
6.A.2 Boiler Cold Water Make-Up ............................ 34
6.A.3 Condensate Drain ........................................... 35
6.A.4 Freeze Protection ........................................... 35
6.A.5 Boiler Suggested Piping Schematics .............. 35
6.A.6 Recognized Chemicals ................................... 36
6.B Water Heater.........................................42
6.B.1 Heater Water Quality ...................................... 42
6.B.2 Piping Requirements ...................................... 42
6.B.3 Cold Water Make-Up ...................................... 42
6.B.4 Condensate Drain ........................................... 42
6.B.5 Freeze Protection ........................................... 42
6.B.6 Heater Suggested Piping Schematics ............ 42
6.B.7 Heater Suggested Pumps .............................. 43
SECTION 7
INSTALLATION AND WIRING
7.A Installation Warnings ...................................... 45
7.B Main Power Connections ................................ 45
7.B.1 Pump Connections and Operation ................. 45
7.B.2 Vari-Prime (optional variable speed pump control) ..... 46
7.C Hydronic Heating Using
External Modulation Control .......................... 46
7.D Optional Field Connections ............................ 46
7.E Lead Lag Connections .................................... 48
7.F Building Automation System Connections ...... 49
7.G System Wiring Diagram .................................. 51
7.H Ladder Diagram .............................................. 52

ii
NEOTHERM Commercial Boilers and Water Heaters
SECTION 11
TROUBLESHOOTING
11.A About Lockouts, Holds, and Alerts ................... 84
11.A.1 Responding to a Lockout, Hold, or Alert ...... 84
11.A.2 Viewing the Lockout and Alert Histories ....... 84
11.B Troubleshooting Table ...............................86 - 94
11.C Diagnostic Tests and Input/Output Indicators .. 94
11.D Lead Lag Follower Diagnostics ........................ 95
11.E Statistics ........................................................... 95
11.F Analysis ............................................................ 95
11.G Control Snapshot ............................................. 95
11.H Operating Sequence ........................................ 96
SECTION 12
REPLACEMENT PARTS
12.A General Information ....................................... 96
12.B Parts List ...................................................96-99
12.C Parts Illustrations ....................................99-106
SECTION 8
USING THE TOUCH SCREEN
8.A The Touch Screen .......................................... 53
8.B Using the Touch Screen ................................. 53
8.C Login (required for some parameters) ............ 54
8.D Verication Process for
Safety-Related Parameters ............................ 55
8.E Checking Individual Parameters ..................... 56
8.F Setting the Date and Time .............................. 57
8.G The Conguration Menu......................58
8.G.1 System Identication & Access ....................... 59
8.G.2 Heat Conguration .......................................... 59
8.G.2.a CH - Central Heat Conguration ................... 59
8.G.2.b Setting Up 4-20 mA Setpoint ........................ 59
8.G.3 Outdoor Reset Conguration .......................... 60
8.G.4 DHW - Domestic Hot Water Cong ................ 60
8.G.5 Warm Weather Shutdown Cong ................... 60
8.G.6 Demand Priority Conguration ....................... 61
8.G.7 Modulation Conguration ................................ 61
8.G.8 Pump Connections ......................................... 61
8.G.9 Statistics Conguration ................................... 62
8.G.10 High Limits ...................................................... 62
8.G.11 Stack Limits .................................................... 62
8.G.12 Anti-Condensation Conguration ................... 62
8.G.13 Frost Protection .............................................. 62
8.G.14 System Conguration ..................................... 62
8.G.15 Fan Conguration ........................................... 63
8.G.16 Sensor Conguration ...................................... 63
8.G.17 Lead Lag Follower Conguration .................... 64
8.G.18 Lead Lag Leader Conguration ...................... 66
8.G.18.a About Lead Lag Operation ........................ 69
8.H Congure for a
Building Automation System ........................... 71
8.I Combustion Setup .......................................... 72
8.J Adjusting CO2 ................................................ 74
SECTION 9
FIRST START UP AND ADJUSTMENT
9.A Filling the Boiler System ................................. 77
9.B First Operation ................................................ 78
9.C Shutting Down the Unit ................................... 78
9.D Restarting the Unit .......................................... 78
SECTION 10
MAINTENANCE
10.A System Maintenance ..................................... 79
10.B Appliance Maintenance
and Component Description ........................... 79
10.C Battery Backup for Date & Time ..................... 82
10.D Gas Conversion .............................................. 83

LAARS Heating Systems

Page 5
Model Nomenclature
SECTION 1
GENERAL INFORMATION
1.A Introduction
1.B Warranty
1.C Model Identication
NEOTHERM Commercial Boilers and Water Heaters
NOTE: Throughout the content of this manual,
the NeoTherm will be referred to as a ‘unit’.
unit = NeoTherm
LAARS Heating Systems NeoTherms are covered by a
limited warranty. The owner should complete the warranty
registration at www.Laars.com.
All warranty claims must be made to an authorized
LAARS Heating Systems representative. Claims must
include the serial number and model (this information
can be found on the rating plate), installation date, and
name of the installer. Shipping costs are not included in
the warranty coverage.
This manual provides information necessary for the
installation, operation, and maintenance of LAARS
Heating Systems NeoTherm boilers and water heaters.
Read it carefully before starting the installation.
All application and installation procedures should
be reviewed completely before proceeding with the
installation. Consult the LAARS Heating Systems
factory, or local factory representative, with any
problems or questions regarding this equipment.
Experience has shown that most operating problems
are caused by improper installation.
NeoTherm is protected against over pressurization. A
pressure relief valve is included with each NeoTherm.
Some NeoTherms may require that the PRV be
installed prior to lling the system. Refer to Figures 2-9
for PRV locations.
Consult the Rating Plate on the side of the unit. The
following information describes the Model Identication
(Model Nomenclature).
(1-2) Model Series Designation
N T = NeoTherm
(3) Usage
H = Hydronic
V = Volume Water
(4-6) Size
1 5 0 = 150,000 BTU/hr input, NTV only
1 9 9 = 199,000 BTU/hr input, NTV only
2 8 5 = 285,000 BTU/hr input, NTV only
3 9 9 = 399,000 BTU/hr input
5 0 0 = 500,000 BTU/hr input
6 0 0 = 600,000 BTU/hr input
7 5 0 = 750,000 BTU/hr input
8 5 0 = 850,000 BTU/hr input
(7) Fuel
N = Natural Gas
P = LP Gas
(8) Options Code
X = Standard US
J = CSD-1, FM, GAP, (U.S. size 500-850 only)
C = Standard Canada
D = CSD-1 (Canada 500-800 only)
E = OUTDOOR (U.S.)
F = OUTDOOR (Canada NTH 399-850 only)
G = CSD-1, OUTDOOR (U.S. 500-850 only)
H = CSD-1, OUTDOOR (Canada 500-850 only)
(9) Pump Options
N = Pump included (N/A for outdoor NTV 750 & 850)
X = No pump
W= HLW w/ Pump (NTV only)
L = HLW w/out Pump (NTV only)
(10) Revision
3 = Third version
v
12 3 456 7 8 9 10
NT 3
N T N - Natural Indoor Units X - No pump 3 - Third
1 5 0 P - Propane X - Standard U.S. N - Pump included
1 9 9 C - Standard Canada (N/A for outdoor
H - Hydronic 2 8 5 J - CSD-1 (U.S. 500-850 only) NTV 750 & 850)
Boiler 3 9 9 D - CSD-1 (Can 500-850 only) L - Opt. HLW no pump
V - Volume 5 0 0 Outdoor Units (NTV only)
Water 6 0 0 E - Standard U.S. W - Opt. HLW w/ pump
7 5 0 F - Standard Canada (NTV only)
8 5 0 G - CSD-1 (U.S. 500-850 only) (N/A for outdoor
H - CSD-1 (Can 500-850 only) NTV 750 & 850)
OPTIONS REVISIONPUMP OPTIONSSERIES
USAGE
SIZE
MBTU/h FUEL

Page 6
1.D Safety Notes
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 CSA B149.1 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
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.
CAUTION 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 throughout this manual to bring attention to the presence of hazards with various risk
levels and to o󰀨 er important information concerning 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
LAARS Heating Systems

Page 7
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 Code ANSI/NFPA No. 70 - latest
Edition, or 2) CSA STD. 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. A National 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) CSA B149.1 “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
Code ANSI/NFPA No. 70-latest Edition, or
2) CSA STD. C22.1 “Canadian Electrical Code - Part
1”. This appliance must be electrically grounded in
accordance with these codes.
NEOTHERM Commercial Boilers and Water Heaters

Page 8
Figure 1. All models open from the front
DOOR
HANDLE
(PULL TO OPEN)
INDOOR OUTDOOR
(RELEASE BOTH
LATCHES TO
OPEN)
DOOR LATCHES
2 SCREWS
FASTEN FRONT
PANEL INTO
PLACE
ON / OFF
SWITCH
THE TOUCH SCREEN ON
OUTDOOR UNIT IS LOCATED
BEHIND FRONT PANEL
1.E Model Overview
These units are o󰀨ered in both Indoor and Outdoor
models for all sizes.
NOTE: Outdoor Installation of volume water heaters
not permitted in Canada.
The physical appearance of the indoor and outdoor units
is drastically di󰀨erent because the outdoor model o󰀨ers
a fully weathertight enclosure that hides the touchscreen.
Whereas the indoor model is not fully weathertight and
the touchscreen can be accessed without having to open
the unit. See Figure 1 through Figure 9.
Both the indoor and the outdoor models have the
On/O󰀨 switch on the outside of the unit.
Both also have the Rating Plate on the outside panel
to the right. See Figure 8 on page 12
The only component (interior) di󰀨erence between the
indoor and outdoor models is that all of the piping for the
outdoor model, with the exception of the exhaust vent, is
at the BACK of the unit. Figure 9 on page 13
The gas connection, the air inlet, and the water inlet and
outlet are all at the back of the unit. This is consistent for
all sizes.
LAARS Heating Systems

Page 9
Figure 3. Location of Components, Size 285
EXHAUST VENT CONNECTION
AIR INLET CONNECTION
GAS CONNECTION
TOUCHSCREEN
HEAT EXCHANGER
GAS VALVE VENTURI
AIR/ GAS
BLOWER
WATER INLET
WATER OUTLET
PRESSURE RELIEF VALVE
AIR PRESSURE SWITCH
DRAIN VALVE
CONDENSATE TRAP
AIR TRANSITION
ON / OFF SWITCH
Figure 2. Location of Components, Sizes 150-199
EXHAUST VENT CONNECTION
GAS CONNECTION
AIR PRESSURE SWITCH
TOUCHSCREEN
HEAT EXCHANGER GAS VALVE
VENTURI
AIR/ GAS
BLOWER
PRESSURE RELIEF VALVE
WATER INLET
WATER OUTLET
AIR INLET CONNECTION
DRAIN VALVE
CONDENSATE TRAP
AIR TRANSITION
ON / OFF SWITCH
NEOTHERM Commercial Boilers and Water Heaters

Page 10
EXHAUST VENT CONNECTION
GAS CONNECTION
TOUCHSCREEN
HEAT EXCHANGER
MANUAL SHUTOFF
GAS VALVE
VENTURI
AIR/ GAS
BLOWER
PRESSURE RELIEF VALVE
WATER INLET
WATER OUTLET
AIR INLET CONNECTION
DRAIN VALVE
CONDENSATE TRAP
GAS VALVE
ON / OFF SWITCH
Figure 4. Location of Components, Indoor Size 399
Figure 5. Location of Components, Indoor Size 500
EXHAUST VENT CONNECTION
PRESSURE RELIEF VALVE
TOUCHSCREEN
HEAT EXCHANGER
MANUAL SHUTOFF
GAS VALVE
VENTURI
GAS VALVE
WATER INLET
WATER OUTLET
AIR INLET CONNECTION
DRAIN VALVE
CONDENSATE TRAP
GAS CONNECTION
AIR/ GAS BLOWER
GAS PRESSURE
SWITCH
AIR PRESSURE SWITCH
ON / OFF SWITCH
LAARS Heating Systems

Page 11
Figure 6. Location of Components, Size 600
EXHAUST VENT CONNECTION
GAS CONNECTION
PRESSURE RELIEF VALVE
TOUCHSCREEN
HEAT EXCHANGER
MANUAL SHUTOFF
GAS VALVE
VENTURI
AIR/ GAS BLOWER
AIR PRESSURE SWITCH
WATER INLET
WATER OUTLET
AIR INLET CONNECTION
DRAIN VALVE
CONDENSATE TRAP
GAS VALVE
MANUAL SHUTOFF
GAS VALVE
ON / OFF SWITCH
Figure 7. Location of Components, Sizes 750 and 850
WATER INLET
WATER OUTLET
AIR INLET
DRAIN VALVE
CONDENSATE TRAP
AIR/ GAS BLOWER
PRESSURE RELIEF
VALVE
TOUCHSCREEN
HEAT EXCHANGER
EXHAUST VENT
CONNECTION
VENTURI
GAS VALVE
GAS CONNECTION
MANUAL SHUTOFF
GAS VALVE
ON / OFF SWITCH
NEOTHERM Commercial Boilers and Water Heaters

Page 12
PRV
GAS CONNECTION
PRV
EXHAUST
VENT
WATER INLET
WATER OUTLET
AIR INLET
Indoor 850 MBH
RATING PLATE
For piping dimensiona/locations for all
Indoor units, See Table 1 on page 14
GAS
CONNECTION
CONDENSATE
TRAP OUTLET
(Trap is built-in)
RATING PLATE
Figure 8. Connection piping is on the BACK for ALL Outdoor Sizes
GAS
CONNECTION
EXHAUST
VENT
WATER INLET
WATER OUTLET
AIR INLET
CONDENSATE
TRAP OUTLET
(Trap is built-in)
Indoor 150 MBH
For piping dimensions/
locations for all Indoor units,
See Table 1 on page 14
LAARS Heating Systems

Page 13
GAS
CONNECTION
EXHAUST
VENT
WATER INLET
WATER OUTLET*
POWER SUPPLY
FOR PUMP
(if ordered with
a pump)
AIR INLET
FILTER BOX
Outdoor 850 MBH
Figure 9. Connection piping is on the BACK for ALL Outdoor Sizes
*PRV must be added to this pipe
during installation.
RATING PLATE
For piping dimensions/locations for all
Outdoor units, See Table 2 on page 16
CONDENSATE
TRAP OUTLET
(Trap is built-in)
RATING PLATE
WATER INLET
WATER OUTLET*
AIR INLET
FILTER BOX
GAS
CONNECTION
*PRV must be added to this pipe
during installation.
EXHAUST
VENT
CONDENSATE
TRAP OUTLET
(Trap is built-in)
Outdoor 150 MBH
For piping dimensions/
locations for all outdoor units,
See Table 2 on page 16
NEOTHERM Commercial Boilers and Water Heaters

Page 14
For Water Connection Pipe Sizes, See “Table 15.
Water Connection Pipe Sizes” on page 34
Table 1. Dimension Drawing, Indoor Sizes 150-850
A B C D E F G J K M N
Size in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm
150 13¼ 34 5¼ 14 18¼ 46 3¼ 810¾ 28 7½ 19 14¼ 36 19½ 49 7½ 19 15¼ 39 13 33
199 20½ 52 5¼ 14 18¼ 46 3¼ 817¾ 45 7½ 19 14¼ 36 19½ 49 11¾ 30 15¼ 39 13 33
285 20¼ 52 7¼ 19 19½ 50 6¼ 16 11¼ 29 13½ 34 14 36 15 38 17 43 18¾ 48 13 33
399 25 64 5¼ 13 19½ 50 4¼ 11 14¾ 37 18½ 47 19¼ 49 16½ 42 21¾ 55 18¾ 48 13 33
500 30¼ 77 5¼ 13 19½ 50 4¼ 11 15¼ 38 20 51 20½ 52 19 48 26 66 18¾ 48 13 33
600 29¾ 76 513 19½ 50 4¼ 11 15 38 20 51 3819 48 26 66 18¾ 48 8¼ 21
750 35½ 90 615 19½ 50 5¼ 13 19 48 40½ 103 3¼ 819 48 30¾ 78 18¾ 48 8¼ 21
850 39¾ 101 615 19½ 50 5¼ 13 19 48 44¾ 114 3½ 919 48 35 89 18¾ 48 8¼ 21
LAIR INLET VENT
SIZE in cm in cm in cm
150 19½ 49 37.6 37.6
199 26¾ 68 37.6 37.6
285 26¾ 68 411 411
399 31½ 80 411 411
500 37¾ 96 411 411
600 37¾ 96 411 411
750 51 130 411 617
850 55¼ 140 411 617
1.F Dimensions, Indoor Models
(length)
L
SUGGESTED SERVICE CLEARANCE
38 1/2(98)
8 3/4
(22)
7 1/2
(19)
25 (64)
Dimensions are nominal and are shown
in inches, cm.
*Unit is shipped with adapters for the air
and vent that accept standard pipe of
the proper size and type.
Table 1. (dimensions continued)
LAARS Heating Systems

Page 15
L
SUGGESTED SERVICE CLEARANCE
38 1/2(98)
8 3/4
(22)
7 1/2
(19)
25 (64)
L
SUGGESTED SERVICE CLEARANCE
38 1/2(98)
8 3/4
(22)
7 1/2
(19)
25 (64)
All Indoor Units have a very
similiar component design with
piping dimensions/locations
that increase as the unit size
increases.
Water and gas piping is
always on the left side of the
unit. Table 1 gives the exact
dimensions for all of the
di󰀨erent model sizes.
ALL Models
See “Table 3. Suggested
Service Clearances” on
page 20
NEOTHERM Commercial Boilers and Water Heaters

Page 16
For Water Connection Pipe Sizes, See “Table 15.
Water Connection Pipe Sizes” on page 34
AIR FILTER
OUTLET
WATER
WATER
INLET
BOX
GAS INLET CONDENSATE
TRAP OUTLET
D
B
J
A C
G
E
F
VENT K
8 (21)
13 (33)
9 (23)
38 1/2(98)
25 (64 )
26 (66 )
FRONT VIEW
RIGHT SIDE VIEW BACK VIEW
TOP VIEW
L5 1/2(9)
TTotal length
SUGGESTED SERVICE CLEARANCE
12 (31) 12
(31)
12 (31)
Dimensions are nominal and are shown
in inches, cm.
*Unit is shipped with adapters for the air
and vent that accept standard pipe of
the proper size and type.
Table 2. Dimension Drawing, OUTDOOR Sizes 150-850
1.G Dimensions, Outdoor Models
285 - 500 MBH
26 (66)
25 (64)
SIZE in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm
150 6-1/4" 16 11" 28 13" 33 17-1/4" 43.8 23-1/2" 60 18" 45.7 27" 69 23-1/2" 60 5-1/4" 13 20" 60 25-1/2" 65 37.6
199 6-1/4" 16 11" 28 13" 33 17-1/4" 43.8 23-1/2" 60 18" 45.7 27" 69 24-1/2" 60 5-1/4" 13 27" 68.6 32-1/2" 82.5 37.6
285 6" 15.5 11" 28 5" 13 17-1/4" 43.8 24" 61 19" 48 28-1/4" 72 12" 30.5 7-1/4" 18.4 27" 68.6 32-1/2" 82.5 411
399 8" 15.5 19-1/2" 50 7-3/4" 20 17-1/4" 43.8 24" 61 19" 48 28-1/4" 72 12" 30.5 6" 15.2 31-1/4"" 80.5 37-3/4" 96 411
500 5" 13 17-3/4" 45 5" 13 8-1/4" 21 24" 61 19" 48 29-1/4" 74 12" 30.5 5.5" 14 38" 96.5 43-1/2" 110.5 411
600 33-1/2" 85 3.0" 85" 13 8-1/4" 21 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 38" 96.5 43-1/2" 110.5 411
750 32-3/4" 83.2 3.0" 85-1/4" 13.4 17-1/4" 43.8 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 51-1/4" 130 57-3/4" 146.7 617
850 32-3/4" 83.2 3.0" 85-1/4" 13.4 17-1/4" 43.8 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 55-3/4" 141.5 61-1/4" 155.5 617
EF VENT ABC D GJK
L(Length) T(TotalLength)
ALL Model Sizes
See “Table 3. Suggested Service Clearances” on page 20
LAARS Heating Systems

Page 17
J
A
G
E
D B
F
BACK VIEW
C
AIR FILTER
WATER
OUTLET
WATER
INLET
BOX
GAS INLET
CONDENSATE
TRAP OUTLET
L
AIR FILTER
KNOCK-OUTS FOR
POWER TO
ALL OPTIONAL
EQUIPMENT
OUTLET
WATER
WATER
INLET
BOX
GAS INLET
CONDENSATE
TRAP OUTLET
D
F
B
J
E
G
A
C
VENT K 8 21
13 33
26 (66 )
FRONT VIEW RIGHT SIDE VIEW
BACK VIEW
TOP VIEW
L
AIR FILTER
OUTLET
WATER
WATER
INLET
BOX
GAS INLET
CONDENSATE
TRAP OUTLET
D
F
B
J
E
G
A
C
VENT K 8 21
13 33
26 (66 )
FRONT VIEW RIGHT SIDE VIEW
BACK VIEW
TOP VIEW
Table 2. (dimensions ontinued)
600 MBH
BACK VIEWS of the Outdoor Models
750 - 850 MBH
150 - 199 MBH
SIZE in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm
150 6-1/4" 16 11" 28 13" 33 17-1/4" 43.8 23-1/2" 60 18" 45.7 27" 69 23-1/2" 60 5-1/4" 13 20" 60 25-1/2" 65 37.6
199 6-1/4" 16 11" 28 13" 33 17-1/4" 43.8 23-1/2" 60 18" 45.7 27" 69 24-1/2" 60 5-1/4" 13 27" 68.6 32-1/2" 82.5 37.6
285 6" 15.5 11" 28 5" 13 17-1/4" 43.8 24" 61 19" 48 28-1/4" 72 12" 30.5 7-1/4" 18.4 27" 68.6 32-1/2" 82.5 411
399 8" 15.5 19-1/2" 50 7-3/4" 20 17-1/4" 43.8 24" 61 19" 48 28-1/4" 72 12" 30.5 6" 15.2 31-1/4"" 80.5 37-3/4" 96 411
500 5" 13 17-3/4" 45 5" 13 8-1/4" 21 24" 61 19" 48 29-1/4" 74 12" 30.5 5.5" 14 38" 96.5 43-1/2" 110.5 411
600 33-1/2" 85 3.0" 85" 13 8-1/4" 21 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 38" 96.5 43-1/2" 110.5 411
750 32-3/4" 83.2 3.0" 85-1/4" 13.4 17-1/4" 43.8 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 51-1/4" 130 57-3/4" 146.7 617
850 32-3/4" 83.2 3.0" 85-1/4" 13.4 17-1/4" 43.8 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 55-3/4" 141.5 61-1/4" 155.5 617
EF VENT ABC D GJK
L(Length) T(TotalLength)
SIZE in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm in cm
150 6-1/4" 16 11" 28 13" 33 17-1/4" 43.8 23-1/2" 60 18" 45.7 27" 69 23-1/2" 60 5-1/4" 13 20" 60 25-1/2" 65 37.6
199 6-1/4" 16 11" 28 13" 33 17-1/4" 43.8 23-1/2" 60 18" 45.7 27" 69 24-1/2" 60 5-1/4" 13 27" 68.6 32-1/2" 82.5 37.6
285 6" 15.5 11" 28 5" 13 17-1/4" 43.8 24" 61 19" 48 28-1/4" 72 12" 30.5 7-1/4" 18.4 27" 68.6 32-1/2" 82.5 411
399 8" 15.5 19-1/2" 50 7-3/4" 20 17-1/4" 43.8 24" 61 19" 48 28-1/4" 72 12" 30.5 6" 15.2 31-1/4"" 80.5 37-3/4" 96 411
500 5" 13 17-3/4" 45 5" 13 8-1/4" 21 24" 61 19" 48 29-1/4" 74 12" 30.5 5.5" 14 38" 96.5 43-1/2" 110.5 411
600 33-1/2" 85 3.0" 85" 13 8-1/4" 21 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 38" 96.5 43-1/2" 110.5 411
750 32-3/4" 83.2 3.0" 85-1/4" 13.4 17-1/4" 43.8 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 51-1/4" 130 57-3/4" 146.7 617
850 32-3/4" 83.2 3.0" 85-1/4" 13.4 17-1/4" 43.8 24" 61 19" 48 29-1/4" 74 12" 30.5 5-3/4" 14.6 55-3/4" 141.5 61-1/4" 155.5 617
EF VENT ABC D GJK
L(Length) T(TotalLength)
Ø
The Outdoor versions have a greater component location
variance than the Indoor models. 4 Back Views are given to
show the piping dimensions/locations for all of the di󰀨erent
piping layouts. Table 2 gives the exact dimensions for all of the
di󰀨erent model sizes.
NEOTHERM Commercial Boilers and Water Heaters

Page 18
80/105 150/199 285 399 500 600 750/850
Flow Switch Kit (ow switch, 2 wires, and an NPT tee)
1 1 1 1
Exhaust Adapter Assembly
1 1
Grid Screen, Venting
2 2 2
Vent Adapter, 6” PVC to 6” Stainless Steel
1
NPT Pipe (for ow switch)
1 1 1 1
Grommets for ow switch wires
2 2 2 2
Some accessory
items may be shipped
in separate packages.
Verify receipt of all
packages listed on
the packing slip.
Inspect everything for
damage immediately
upon delivery, and
advise the carrier
of any shortages or
damage. Any such
claims should be led
with the carrier.
The carrier, not the
shipper, is responsible
for shortages and
damage to the
shipment whether
visible or concealed.
Optional Indoor Pump Kit
1.H The Installation Kit (installation parts box).
The Indoor models are shipped in a single crate with the Installation Kit (cardboard box). Check the contents of
the Installation Kit with the items listed in Figure 10 and Figure 11. Additional parts may be packed inside the unit.
Figure 10. Standard Installation Components
Figure 11. Additional Components, depending on model size and conguration.
Document Bag
(all documents in one bag)
Term inal Block Jumper
(the Terminal Block Jumper is in the document bag)
Sen sor Kits (Tank, Outdoor and System Sensors, all in the
same bag (2 boxes, a sensor, and a wire).
Volume Water Heaters will not have an Outdoor Sensor
Air Intake Terminal Assembly
(elbow and a screen)
Vent Pipe
Exhaust Terminal Assembly
(end pipe and a screen),
Tem p/Pressure Gauge Kit
(a bushing, an NPT Tee, and the gauge in a small box)
LAARS Heating Systems

Page 19
NOTE: The pump and outdoor housing will
typically be shipped inside the unit. Pump will
need to be piped and wired on site. A 62” long
wire harness is provided but a conduit will need to
be provided by the electrician at the time of boiler
installation.
EXPLODED VIEW
ASSEMBLED
VIEW
50D4140/QTY. 20D4141/QTY. 15D4140/QTY. PART NO. DESCRIPTION ITEM NO.
BOM Table
444 F0024300 SCREW, #10-16 X 5/8", STL, HX WSHR HD, #3 PT 6
222 15D3116 SIDE PANEL, PUMP COVER, NTOD 5
111
15D3115 TOP PANEL, PUMP COVER, NTOD 4
111 50D7605 HARNESS, PUMP, NTOD 150-500 3
- - 2 A2115900 FLANGE, PUMP, 1-1/4" NPT, 3 7/16" BOLT PAT, BRASS
22 - - A2116000 FLANGE, PUMP, 1-1/2" NPT, BRASS, 3 7/16" BOLT PAT, BRASS
- 2 - A2116100 FLANGE, PUMP, 1-1/4" NPT, 3 5/32 BOLT PAT, BRASS
- 1 - A2120700 PUMP, CIRCULATOR ARMSTRONG
11 - - A2120800 PUMP, CIRCULATOR, ARMSTRONG E22.2B
- - 1 A2120600 PUMP, CIRCULATOR, ARMSTRONG E11.2LFB
PART NUMBER MODEL
15D4140 15D0701
20D4141 20D0701
50D4140 30D0701
50D4140 40D0701
50D4140 50D0304
50D4140 50D0704
D
C
B
A
B
C
D
1
2
3
4
4
3
2
THIS DOCUMENT AND THE INFORMATION CONTAINED HEREIN ARE
PROPRIETARY TO LAARS HEATING SYSTEMS AND SHALL NOT BE
REPRODUCED, TRANSFERRED TO OTHER DOCUMENTS, USED OR
DISCLOSED TO OTHERS FOR MANUFACTURING OR ANY OTHER
PURPOSE EXCEPT AS SPECIFICALLY AUTHORIZED IN WRITING
BY LAARS HEATING SYSTEMS.
FMA56A
DWG NO.
50D4140
SH
1
REV
A
CJ 5/17/16
REVISIONS
REV.
CHANGE:
APPR
ENGR APPR
ECN
DRAFT
CHECK
REMOVED ITEM 2 A2116100 FROM 50D4140.
A
15-127N-05 XR 5/17/16
SCALE: NONE
INTENDED SIZE:
SOFTWARE
DWG. NO:
C
SHEET 1 OF 1
REV.
APPROVALS
DRAFT
ENGR
APPR
UNLESS OTHERWISE SPECIFIED:
DO NOT SCALE DRAWING.
THIRD ANGLE PROJECTION.
DIMENSIONS ARE IN INCHES.
TOLERANCES ARE:
MATERIAL:
FINISH
SEE PARTS LIST
NA
XR 4/14/16
S
CJ 4/14/16
DECIMALS .X .1
DECIMALS .XX
.03
DECIMALS .XXX
.010
ANGLES 1
TITLE:
FRACTIONS 1/8"
PUMP ASSEMBLY,
NTVOD 150-500
50D4140 A
PROJECT
0080
11 1/4 ”
11 1/4 ”
6 1/2 ”
HARNESS
EXPLODED VIEW
ASSEMBLED
VIEW
50D4140/QTY. 20D4141/QTY. 15D4140/QTY. PART NO. DESCRIPTION ITEM NO.
BOM Table
444 F0024300 SCREW, #10-16 X 5/8", STL, HX WSHR HD, #3 PT 6
222 15D3116 SIDE PANEL, PUMP COVER, NTOD 5
111 15D3115 TOP PANEL, PUMP COVER, NTOD 4
111 50D7605 HARNESS, PUMP, NTOD 150-500 3
- - 2 A2115900 FLANGE, PUMP, 1-1/4" NPT, 3 7/16" BOLT PAT, BRASS
22 - - A2116000 FLANGE, PUMP, 1-1/2" NPT, BRASS, 3 7/16" BOLT PAT, BRASS
- 2 - A2116100 FLANGE, PUMP, 1-1/4" NPT, 3 5/32 BOLT PAT, BRASS
- 1 - A2120700 PUMP, CIRCULATOR ARMSTRONG
11 - - A2120800 PUMP, CIRCULATOR, ARMSTRONG E22.2B
- - 1 A2120600 PUMP, CIRCULATOR, ARMSTRONG E11.2LFB
PART NUMBER MODEL
15D4140 15D0701
20D4141 20D0701
50D4140 30D0701
50D4140 40D0701
50D4140 50D0304
50D4140 50D0704
D
C
B
A
B
C
D
1
2
3
4
4
3
2
THIS DOCUMENT AND THE INFORMATION CONTAINED HEREIN ARE
PROPRIETARY TO LAARS HEATING SYSTEMS AND SHALL NOT BE
REPRODUCED, TRANSFERRED TO OTHER DOCUMENTS, USED OR
DISCLOSED TO OTHERS FOR MANUFACTURING OR ANY OTHER
PURPOSE EXCEPT AS SPECIFICALLY AUTHORIZED IN WRITING
BY LAARS HEATING SYSTEMS.
FMA56A
DWG NO.
50D4140
SH
1
REV
A
CJ 5/17/16
REVISIONS
REV.
CHANGE:
APPR
ENGR APPR
ECN
DRAFT
CHECK
REMOVED ITEM 2 A2116100 FROM 50D4140.
A
15-127N-05 XR 5/17/16
SCALE: NONE
INTENDED SIZE:
SOFTWARE
DWG. NO:
C
SHEET 1 OF 1
REV.
APPROVALS
DRAFT
ENGR
APPR
UNLESS OTHERWISE SPECIFIED:
DO NOT SCALE DRAWING.
THIRD ANGLE PROJECTION.
DIMENSIONS ARE IN INCHES.
TOLERANCES ARE:
MATERIAL:
FINISH
SEE PARTS LIST
NA
XR 4/14/16
S
CJ 4/14/16
DECIMALS .X .1
DECIMALS .XX
.03
DECIMALS .XXX
.010
ANGLES 1
TITLE:
FRACTIONS 1/8"
PUMP ASSEMBLY,
NTVOD 150-500
50D4140 A
PROJECT
0080
11 1/4 ”
11 1/4 ”
6 1/2 ”
HARNESS
AIR FILTER
OUTLET
WATER
WATER
INLET
BOX
GAS INLET CONDENSATE
TRAP OUTLET
D
B
J
A C
G
E
F
VENT K
8 (21)
13 (33)
9 (23)
38 1/2(98)
25 (64 )
26 (66 )
FRONT VIEW RIGHT SIDE VIEW BACK VIEW
TOP VIEW
L5 1/2(9)
TTotal length
SUGGESTED SERVICE CLEARANCE
12 (31) 12
(31)
12 (31)
TOP PANEL
SIDE PANEL
SIDE PANEL
WATER INLET
FLOW
FLOW
Outdoor Pump Kit
150 - 500 MBh
Figure 13. Outdoor Pump Kit
Figure 12. Additional components for
outdoor models.
The OUTDOOR Model Installation Kits, in
addition to what is shown in Figure 10 and
Figure 11, will include:
Vent Pipe Extender,
Pipe Adapter,
Bird Screen,
PRV,
NPT Pipe Tee
NOTE: Outdoor Installation of this
volume water heater is not
permitted in Canada.
NEOTHERM Commercial Boilers and Water Heaters

Page 20
SECTION 2
LOCATING THE UNIT
2.A General Information
The ‘Indoor’ unit is designed and CSA-certied
for indoor installations only.
The ‘Outdoor’ unit is designed and CSA-certied for
outdoor installations only. Outdoor installation of
this unit is not permitted in Canada.
If installing 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.
The appliance should be located to provide clearances on
all sides for maintenance and inspection. It 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 such a location is
not available, it is recommended that a suitable drain pan,
adequately drained, be installed under the appliance.
Always install the unit on a rm, level surface.
The unit is design certied by CSA-International for
installation on combustible ooring; in basements; in
closets, utility rooms or alcoves. These units must never be
installed on carpeting. The location for the unit should be
chosen with regard to the vent pipe lengths and external
plumbing and on a level surface.
The Indoor units 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 Outdoor units must be installed at least 10 ft (the vent
pipe) from any door or window. The exhaust vent shall
not be under any overhang or roof. Use only the vent
components included with the boiler.
The dimensions and requirements that are shown in Table
3 should be met when choosing the locations for the
appliance.
INDOOR OUTDOOR
UNIT SURFACE INCHES CM INCHES CM
Left Side 12.5 12 31
Right Side 12 31 12 31
Top (for ue) 24 61 48 122
Back 615 12*31*
Closet, Front 12.5 12.5
Front 24 61 24 61
Vent Per Vent Manufacturer
Certied by CSA for zero clearance to combustible materials on all sides.
*from lter box face. See “Table 2. Dimension Drawing, OUTDOOR
Sizes 150-850” on page 16
Table 3. Suggested Service Clearances
2.B Locating Appliance for 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 4 are followed.
For concentric vent terminal kit (optional), follow
installation instructions included with the kit.
LAARS Heating Systems