Laars LT Series Owner's manual

Installation and Operation
Instructions for
LT Series
Wall-Mounted, Modulating
Gas Condensing Water Heater
Model LT199NRX1 / LT199PRX1
(199,000 BTU/hr)
•Natural Gas (NG) - Factory Configuration
•Propane (LP) - Factory Configuration
WARNING
If the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.
Do not store or use gasoline or other
flammable 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 fire department.
Installation and service must be performed
by a qualified installer, service agency, or gas
supplier.
FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualified in water heater installation and maintenance. Improper installation and/or operation could create
carbon monoxide gas in flue gases which could cause serious injury, property damage, or death. Improper
installation and/or operation will void the warranty.
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 ou ni
d’autres vapeurs ou liquides inflammables dans
le à proximité 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 dans le bâtiment où vous vous
trovez.
•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 qualifié
ou par le fournisseur de gaz.
Installation and Operation Instructions Document 2192

TABLE OF CONTENTS
SECTION 1 Product Accessories
1.1 Introduction ...........................................................3
1.2 Included with the Unit ...........................................3
SECTION 2 Product Characteristics
2.1 Model Nomenclature ............................................4
2.2 Specifications .......................................................5
2.3 Dimensions ...........................................................6
2.4 Names of Components .........................................7
SECTION 3 Safety Regulations
3.1 Safety Symbols ....................................................8
3.2 Safety Precautions and Proper Use .....................9
SECTION 4 Installation
4.14 Re-Circulation Setting ...................................... 33
4.15 Setting the Control Panel ...................................... 37
4.16 Disposal of Condensate .....................................39
4.17 Pressure Relief Valve .........................................40
4.18 Electrical Wiring Connections .............................40
4.19 DIP Switches .....................................................41
4.20 Wiring Diagram ..................................................42
4.21 Ladder Diagram .................................................43
4.22 Electrical Connections .......................................44
SECTION 5 Control Display and Operation
5.1 Control Dial and Buttons ....................................46
5.2 LCD Overview ...................................................47
5.3 Operating Mode ..................................................48
5.4 Status Display Mode ..........................................49
5.5 DHW Set Point Change Mode ...........................50
5.6 Installer Mode ....................................................51
5.7 Error Mode .........................................................52
SECTION 6 Error Codes
6.1 Error Codes .......................................................53
SECTION 7 Troubleshooting
7.1 Diagnostics .........................................................57
SECTION 8 Maintenance
8.1 General Maintenance .........................................58
SECTION 9 Installation Check
9.1 Quick View .........................................................59
9.2 Final check lists ..................................................64
SECTION 10 LT Series Warranty
4.1 Location and Clearances ....................................12
4.2 Wall Mount Bracket ............................................13
4.2.1 The installation height and location ...................13
4.2.2 Hang the Water Heater.......................................13
4.3 Combustion Air ...................................................14
4.3.1 Combustion Air from Room ................................14
4.3.2 Ducted Combustion Air .......................................14
4.4 Venting (Exhaust) ...............................................15
4.5 General Location Guideline ................................18
4.6 Locations for Vent Pipe Terminal .......................19
4.6.1 Direct Venting Clearances .................................19
4.6.2 Non-Direct Venting Clearances .........................20
4.6.3 Venting Requirements in the
Commonwealth of Massachusetts .....................21
4.6.4 Common Vent Test .............................................22
4.7 Air Supply and Vent Connections .......................23
4.7.1 Vent / Air Pipe Lengths .......................................23
4.7.2 Direct Venting .....................................................23
4.7.3 Single Venting ...................................................24
4.8 Vent / Air Pipe Termination .................................24
4.9 Gas Supply and Piping .......................................27
4.10 Gas Supply Pressure .........................................30
4.11 Gas Setup and Adjustment .................................30
4.12 Gas High Altitude Setting ..................................31
4.13 Plumbing Guidelines. ...................................... 32
NOTE: For Cascading Installations, please refer
to document ‘Cascading the LT Series Water
heater’, available online.
4.4.1 Venting (Exhaust) ...............................................16

Page 3
SECTION 1 Product Accessories
Items Descriptions Qty
Tankless Water Heater 1
Installation Instructions and
User’s Manual 1
Wall Mount Bracket 1
Bolts w/Anchors
Vent terminal cap 2" 2
Parts Kit 1
1.1 Introduction
This manual provides information necessary for the
installation, operation, and maintenance o the LT Series.
All application and installation procedures must be read and
reviewed completely beore proceeding with the installation.
Consult the manufacturer, or your local factory representative,
with any problems or questions regarding this equipment.
Experience has shown that most operating problems are
caused by improper installation.
All installations must be made in accordance with
1) American National Standard Z223.1/NFPA54-Latest
1.2 Included with the Unit
Edition "National Fuel Gas Code" or
2) CSA B149.1 "Natural Gas and Propane Installation Code" 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.
4
4

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L
1
T
2
1
3
9 X 1
4 6 8 97
9
5
MODEL NUMBER
Model
Laars
Tankless
Size
199 MBH
Fuel
N - Natural
P - Propane
Option
X - Standard
Revision
1- First
Pump Option
X - No Pump
R - With Recirculation Pump
WARNING
Do not use this appliance if any part has been under water. Immediately call a qualified
service technician to inspect the appliance and to replace any part of the control system and
any gas control that may have been under water.
SECTION 2 Product Characteristics
2.1 Model Nomenclature
The Model Nomenclature is shown on your Rating Plate and consists of a series of letters and numbers
that further identifies the characteristics of your LT Series Water Heater.

Page 5
2.2 Specications
• Temperature
Operating ambient Temperature Range : Range: 14°F to 140°F (-10 to 60°C).
Operating Relative Humidity up to: 90% at 104°F (40°C).
Shipping & Storage Temperature Range of : -4°F to 176°F (-20 to 80°C).
Model Name LT199NRX1/LT199PRX1
Gas Input Rate
MAX 199,000 Btu/h
MIN 18,000 Btu/h
High Elevation 180,000 Btu/h
Hot Water Capacity
35°F Rise 11.1 Gal/min (42 L/min)
45°F Rise 8.7 Gal/min (32.9 L/min)
77°F Rise 5.1 Gal/min (19.3 (L/min)
Installation Indoor / Outdoor Wall Hung (with outdoor vent cap)
Flue System Sealed Combustion Direct Vent, Single Vent, Outdoor
Max Vent Run 2” (60ft) / 3” (150ft) Schedule 40 PVC, CPVC, PP
Orice Size NG (Gas / Needle) 0.330” (8.4mm) / 0.342” (8.7mm)
LP (Gas / Needle) 0.259” (6.6mm) / 0.263” (6.7mm)
Gas Supply Pressure NG 3.5” WC to 10.5” WC
LP 8.0” WC to 14” WC
Manifold Pressure
Gas Type NG LP
Low Fire 2″ VENT 0.1˝ WC -0.05˝ WC
3″ VENT 0.1˝ WC -0.05˝ WC
High Fire 2″ VENT -0.20˝ WC -0.30˝ WC
3″ VENT -0.20˝ WC -0.30˝ WC
Power Supply Main Supply 120V 60Hz
Max Current Less than 2A
Power Consumption
Standby 2.7W
Operation 188W
Anti Freeze 117W
Ignition System Direct Electronic Ignition / Automatic Flame Sensing
Burner System Premixed Metal Fiber Burner
Gas Valve System Air Ratio Valve
Minimum Flow Activation Flow 0.5 GPM
Internal Pipe Material STS 304, Stainless Steel with PPS
Dimensions W 17.3″ – H 27.6″ – D 14.9″
Weight 85 lbs
Water Holding Capacity Under 2 Gallons
Control Panel / Circuit Board PR-952C / NGTH-9600C
Water Pressure MAX 150 psi
MIN 15 psi
Materials Casing Cold Rolled Carbon Steel
Heat Exchanger Heat Exchanger : SS 304
Safety Devices Flame Sensor, Overheat Cut Off Switch , Gas Leak Detector, Water Leak
Detector, Exhaust Temperature Sensor, Water Temperature Sensor