Laars LT Series Operation Instructions Manual
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Laars LT Series Operation Instructions Manual

Wall-mounted, modulating gas condensing water heater
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Installation and Operation Instructions
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.
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.
Installation and Operation
Instructions for
LT Series
Wall-Mounted, Modulating
Gas Condensing Water Heater
Model
•
•
WARNING
LT199NXX1 / LT199PXX1
(199,000 BTU/hr)
Natural Gas (NG) - Factory Configuration
Propane (LP) - Factory Configuration
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
Document 2182A
AVERTISSEMENT

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  • Page 1 Installation and Operation Instructions Document 2182A Installation and Operation Instructions for LT Series Wall-Mounted, Modulating Gas Condensing Water Heater Model LT199NXX1 / LT199PXX1 (199,000 BTU/hr) • Natural Gas (NG) - Factory Configuration • Propane (LP) - Factory Configuration FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician, qualified in water heater installation and maintenance.

  • Page 2: Table Of Contents

    10.2 Fitting Parts ............87 4.9.5 Installing the Common Vent System with PVC or CPVC venting materials (U.S. Installation Only)...40 10.3 Fan & Heat Exchanger Parts ......89 4.9.6 PVC Common Venting Componets Configuration ..45 SECTION 11 LT Series Warranty 4.9.7 Polypropylene Common venting ......45...

  • Page 3: Section 1 Product Accessories

    This manual provides information necessary for the and with the requirement of the local utility or other authorities installation, operation, and maintenance of the LT Series. having jurisdiction. Such applicable requirements take All application and installation procedures must be read and precedence over the general instructions contained herein.

  • Page 4: Section 2 Product Characteristics

    Page 4 SECTION 2 Product Characteristics 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. Model Size Fuel...

  • Page 5: Specifications

    Page 5 Specifications Model Name LT199NXX1 / LT199PXX1 199,000 Btu/h Gas Input Rate 18,000 Btu/h High Elevation 180,000 Btu/h 35°F Rise 11.1 Gal/min (42 L/min) Hot Water Capacity 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...

  • Page 6: Dimensions

    Page 6 Dimensions - [LT199NXX1 / LT199PXX1] 6.9" [175mm] 5.8" [148mm] 4.6" [117mm] 17.3" [440mm] 3.0" [75mm] 2.5" [65mm] 6.1" [155mm] 8.2" [208mm] Description Size Exhaust 2" PVC Air Intake 2" PVC 3/4" NPT Condensate 1/2" NPT Hot Water Connection 3/4"...

  • Page 7: Names Of Components

    Page 7 Names of Components [LT199NXX1 / LT199PXX1] Name of Component Name of Component Vent Pipe Collar Cold Water Inlet Combustion Air Intake Assembly Cold Water Filter Condensate Trap Ignition Transformer Igniter Flow Control valve Flame Detection Sensor Display Panel Manual Power Switch High Limit Switch Sight Glass...

  • Page 8: Section 3 Safety Regulations

    Page 8 SECTION 3 Safety Regulations Safety Symbols WARNING WARNING To avoid product damage, personal injury, or even FOR YOUR SAFETY READ BEFORE possible death, carefully read, understand, and OPERATING follow all the instructions in the Installation and If you do not follow these instructions exactly, a Operation manual before installation, operation fire or explosion could result causing property and service the Water Heater.
  • Page 9 Page 9 This appliance is certified for use at altitudes up to • National Electric Code ANSI/NEPA 70 2,000 ft (609m) without adjusting Altitude settings, • All applicable local, state, national and provincial accordance to the latest Canadian Standard “CSA codes, regulations and laws.

  • Page 10: Safety Precautions And Proper Use

    Page 10 Safety Precautions and Proper Use Before Operation CAUTION When in Operation 1. Caution for Ventilation 1. Check the Gas Type (NG/LP) Ensure that there is unobstructed and sufficient inflow When moving the unit or setting it up for the first and outflow combustion air for the water heater.
  • Page 11 Page 11 Gas leakage test. WARNING Gas supply line must be inspected periodically. Do not use the appliance for any other purpose than for Do not disconnect main power to the water domestic water heating. heater. Do not store combustibles or flammable material such as When you leave home for a extended periods, do gasoline near the appliance.

  • Page 12: Section 4 Installation

    Page 12 SECTION 4 Installation WARNING Location and Clearances Installations must comply with The water heater must be mounted to a suitable wall • All the local, state, provincial, and national codes, by a qualified heating contractor per the provided laws, regulations and ordinances.

  • Page 13: Wall Mount Bracket

    Page 13 Wall Mount Bracket 3" to Top of Unit 4.2.1 The installation height and location Anchors (4) The installation height depends on your installation scenario. With all clearances considered, and given adequate positioning Concrete, for air supply and venting, you will need to determine the Wood, best position to mount the Wall Mount Bracket.

  • Page 14: Combustion Air

    Page 14 SECTION 4. Installation (continued) Combustion Air LT Series water heaters must have provisions for vertical or horizontal duct to the outdoors or spaces combustion and ventilation air in accordance with the that directly communicate with the outdoors and shall...

  • Page 15: Venting (Exhaust)

    Having a backflow preventer in the cold water supply line means that it prevent from thermal The LT Series is a Category IV appliance and may be expansion backflow. Contact the water supplier installed with PVC, CPVC, Polypropylene or Stainless...
  • Page 16 All components used in the vent system must NE PAS METTRE EN COMMUN LES UNITÉS LT be from a certified manufacturer. AVEC UN AUTRE APPAREIL. LT Series unités ne 4 . Vent system components must not be sont jamais autorisés à partager un évent Catégorie I mixed with alternate manufacturers certified avec les appareils.

  • Page 17: Selecting Vent Pipe

    Page 17 4.4.1 Selecting Vent Pipe ● Royal Plumbing Solution - 2" GVS-65 Concentric Vent Termination Kit 1. Polypropylene vent #52CVKGCS6502 The following polypropylene vent components are - 3" GVS-65 Concentric Vent Termination Kit approved for use with this appliance: #52CVKGCS6503 ●...

  • Page 18: General Location Guideline

    Page 18 ● Z-Flex® Z-DENS (Certified to UL1738 and be at least 12" above the normal snow line. In no ULCS636) case should they be less than 12" above grade level. - 2ZDE_87 or 3ZDE_87 (2" or 3" 87° Elbow) - 2ZDE_45 or 3ZDE_45 (2"...

  • Page 19: Locations For Vent Pipe Terminal

    Page 19 Locations for Vent Pipe Terminal 4.6.1 Direct Venting Clearances U.S. Installations (see note 1) Canadian Installations (see note 2) Clearance above grade, veranda, porch, deck, 12 inches (30 cm) 12 inches (30 cm) or balcony See note 6 See note 6 Direct vent only: 12 inches (30cm);...

  • Page 20: Non-Direct Venting Clearances

    Page 20 4.6.2 Non-Direct Venting (Single Pipe) Clearances Description US Non-Direct Canadian Non-Direct Clearance above grade, veranda, porch, deck, or balcony 12 in (30 cm) 12 in (30 cm) 48 in (120 cm) below or Clearance to window or door that may be opening to side of opening;...

  • Page 21: Venting Requirements In The Commonwealth Of Massachusetts

    Page 21 4.6.3 Venting Requirements in the Commonwealth of Massachusetts In Massachusetts the following items are required if 4. Inspection The state or local gas inspector of the the side-wall exhaust vent termination is less than side-wall horizontally vented gas fueled appliance shall seven (7) feet above finished grade in the area of not approve the installation unless, upon inspection, the venting, including but not limited to decks and...

  • Page 22: Common Vent Test

    AVIS NE PAS METTRE EN COMMUN LES UNITÉS DO NOT COMMON VENT LT UNITS WITH LT AVEC UN AUTRE APPAREIL. LT Series ANY OTHER APPLIANCE. LT Series units are unités ne sont jamais autorisés à partager un évent never permitted to share a vent with Category I Catégorie I avec les appareils.

  • Page 23: Air Supply And Vent Connections

    Page 23 Air Supply and Vent Connections 4.7.1 Vent / Air Pipe Lengths 3" Combustion Air / Vent Pipe 2" Combustion Air / Vent Pipe Water Heater model LT199 150' (45M) 60' (18M) Table 6. Maximum Vent / Air Pipe Lengths for either 3" or 2 " Pipes Note : For each elbow, reduce maximum allowable length •...

  • Page 24: Polypropylene Flexible Vertical Vent System

    Page 24 4.7.4 PolyPropylene Flexible Vertical Vent System Flexible (Certified to UL-1738/ULC-S636 ) venting approved for vertical non-direct vent (room air) applications only. The use of proper adapters and supports are required to fully complete the installation. 3" Flexible PP 2"...
  • Page 25 Page 25 Horizontal Vent Termination • Direct Vent - Sidewall Termination Exterior Wall Vent Screens are required 1” MIN Exhaust Elbow 12” MIN 12” MIN Exhaust Apart Exhaust Screen NOTE: The Exhaust must Air Intake Screen NOTE: Must be 12” be equal to or above the Minimum distance Combustion...
  • Page 26 Page 26 • Direct Vent - Optional Side wall Terminations Exterior Wall Concentric Vent Termination • Direct Vent - Optional Horizontal Exterior Wall Side Wall Kit and Vertical Concentric Vent (2" or 3") Side Wall Kit (2" or 3") 12" Minimum clearance Exhaust above highest anticipated snow level or grade,...

  • Page 27: Cascade System

    Page 27 Cascade System 4.9.1 Piping Multiple tankless water heaters can be connected via a cascade communication cable to create a bank of water heaters that work in tandem. One or two (LT199NXX1 / LT199PXX1) units can be cascaded using the cascade communication cable, with multiple units. The unit acting as the leader and the units acting as the followers.
  • Page 28 Page 28 Piping Diagrams for Cascaded Systems (continued) CHECK VALVE STRAINER SHUTOFF VALVE UNION SERVICE 3-WAY SERVICE 3-WAY GAS BALL VALVE ISOLATION VALVE EXPANSION TANK ISOLATION VALVE W/PRV PORT THERMOSTATIC CIRCULATOR TT24 sensor FAUCET CROSSOVER VALVE PUMP PRESSURE RELIEF VALVE Piping Symbol Legend Refer to Sections: 4.9.2: Electrical...
  • Page 29 Page 29 Cascaded System - Recirculation Cascaded System with Storage Tank...
  • Page 30 Page 30 Cascaded System - Recirculation with Storage Tank Cascaded System - Recirculation with RTGR Units...

  • Page 31: Electrical

    Page 31 4.9.2 Electrical Wiring Connections for Cascade. Components Needed : FT1861: (1 per unit) Cascade Communication Cable with Ending Resistor. communication cables Example. If you are cascading 6 tankless units, you will need you will only need one of the included ending resistors. To CN1 RS-485 Primary Connector.

  • Page 32: Cascade Programming

    Page 32 4.9.3 Cascade Programming A. To Program the Tankless Water Heater Leader: Once all of the 'Connection Wires' are made and all units are powered on, there are 3 parameters that need to be programmed on the leader before moving on to the follower units. 10:cn –...
  • Page 33 Page 33 B. To Program the Tankless Water heater Followers: Now move over to the first 'Following' unit and perform only 13:cn – (Unit ID of the cascade system) to each of the following units. 10:cn - (Unit ID of the cascade system) Sets the cascade address for each follower (repeat this step for all followers).
  • Page 34 Page 34 C. Load Transition Charts Follower Rotation Example, Five Unit Cascade Systementer into that Parameter. Cascade Transition - Single Unit Fired Up to Maximum Number of Units Percent Firing Rate per Transition Transition 1 Transition 2 Transition 3 Transition 4 Transition 5 High High...

  • Page 35: Common Vent System (U.s. Installation Only)

    Page 35 4.9.4 Common Vent System (U.S. Installation Only) 4.9.4.1 About the common venting system Consult with the Authority Having Jurisdiction The Common Vent System provides an easy way (AHJ), and all applicable Local, State, National, to install up to 8 tankless water heaters. By sharing and Provincial Codes, Regulation, and Bylaws.
  • Page 36 Page 36 • The common venting system covered in this ■ Clearances Between Multiple Units manual is approved both Single and direct venting Ensure that the installed water heaters or boilers satisfy applications. all installation clearances provided in the manual. It is •...
  • Page 37 Page 37 For installation from Suggested Non-Combustibles and Service 15.3" Combustibles Clearance 10 in (25 cm) 18 in (46 cm) BACK 3/4 in (1.9 cm) 3/4 in (1.9 cm) FRONT 4 in (10 cm) 40 in (101 cm) SIDE 4 in (10 cm) 8 in (20 cm) BOTTOM 10 in (25 cm)
  • Page 38 Page 38 • When cutting vent components, ensure that the cuts WARNING are straight. Chamfer and deburr all edges before installing the components. Use of cellular core PVC (ASTM F891), cellular • All vent joints must be fully tightened. core CPVC, or Radel® (polyphenolsulfone) in •...
  • Page 39 Page 39 ■ Setting the vent type 1. Turn OFF the Power to the Display Control 2. Then, with the display OFF. Press and HOLD the button to get into the Installer Mode. 3. Rotate the Dial until you get to 13:Vt Tap the Dial to enter into that Parameter.

  • Page 40: Installing The Common Vent System With Pvc Or Cpvc Venting Materials (U.s. Installation Only)

    Page 40 4.9.5 Installing the Common Vent System with PVC or CPVC venting materials CAUTION 4.9.5.1 NRV(Non-Return Valve) Common Venting requires a Non-Return Valve on each water heater exhaust connector. Use only the The NRV prevents backflow (back-draft) at the exhaust NRV specified in this manual.
  • Page 41 Page 41 4.9.5.2 Maintenance Periodically check the damper condition inside the 3. Reinstall the cap and cover, and then fix them with NRV through the maintenance port to ensure optimal a set screw. performance of the system. Follow the instructions to check the damper condition and replace the NRV if necessary.
  • Page 42 Page 42 4.9.5.3 Connecting the Pipe to the Common Vent 1. Cut the pipe to the measurement, and note the 4. Apply a moderate amount of primer/glue to length where the fitting will over lap. the inside of the socket, fully coating the area the will over lap the pipe.
  • Page 43 Page 43 4.9.5.4 Connecting the Pipe to the NRV 4.9.4.5 Determining the Length of a Common Venting System 1. Measure 1.3"(33mm) from the end of the vent pipe, then draw an insertion mark at that point all the way Follow the instructions listed below to determine the around the pipe.
  • Page 44 Page 44 ■ Example of a Typical Installation The following illustration depicts an example of a common vent system installed for a cascade system of 8 water heaters. Intake Drain NOTE : The illustration is intended for reference purposes only. ■...

  • Page 45: Pvc Common Venting Componets Configuration

    Page 45 4.9.6 PVC Common Venting Componets Configuration Connection to intake pipe Connection to exhaust pipe 4.9.7 Polypropylene Common venting Item Description 2"Non-Return Valve 2" PVC connector ° elbow 2"x90 2"xD" Tee D" Tee Condensate trap for Main trunk D" Connector End Cap Connection to exhaust pipe Connection to intake pipe...

  • Page 46: Gas Supply And Piping

    Review the following instructions before proceeding with NOTE: The LT Series appliance and all other gas the installation. appliances sharing the gas supply line must be firing at...
  • Page 47 Page 47 4.10 Gas Supply and Piping (continued) The gas connection fitting on the unit is 3/4" male NPT. be installed in the supply line between the shut-off valve and the 3/4" male NPT connection on the Water The supply line must be sized for the maximum Heater.
  • Page 48 Page 48 Natural Gas piping installation. The Water Heater is recommended to be The Water Heater is the first appliance to recommended to be be connected to the the first appliance to gas supply line. be connected to the gas supply line. Other appliance Connection Manual gas shut off valve...

  • Page 49: Gas Conversion

    Page 49 4.10.1 Gas Conversion To convert to a different gas type than on the Rating Plate, order the Propane LP Conversion Kit (Part# ST1148) or Natural Gas Conversion Kit (Part# ST1147), and follow the included Conversion Kit Instruction Procedure. For addition information on the conversion kit and procedure, consult with the factory Technical Support.

  • Page 50: Gas Setup And Adjustment

    Page 50 4.12 Gas Setup and Adjustment Follow these steps. 1. Establish a call for water by opening a hot water WARNING tap. 2. Set up your combustion analyzer and place the Installer may be required to verify combustion sensor in the combustion test port. settings as part of the installation process.

  • Page 51: Gas High Altitude Setting

    4.13 Gas High Altitude Setting (no adjustment is needed below 2000 feet) The LT Series has been set up at the factory for altitudes of less than 2,000 ft, but it may be installed at elevations up to 10,000 ft for use with Natural Gas or Propane. If the...

  • Page 52: Plumbing Guidelines

    Page 52 4.14 Plumbing Guidelines. - Ensure pipe material is suitable for the local codes and industry standards. - The pipe must be cleaned and without any debris. - Do not apply torch heat within 12" of the bottom connections of the unit. - The size of the hot water pipe should be 3/4"...
  • Page 53 Page 53 4.14 Plumbing Guidelines (continued) Water Quality Potable water is defined as drinkable water supplied from a utility or from a well, in compliance with EPA secondary maximum contaminant levels (40 CFR Part 143.3) as shown in Table 14. Water quality must be within these maximum allowable parameters.

  • Page 54: Setting The Water Heater Mode

    Page 54 4.15 Setting the Water Heater Mode No Recirculation External Pump Mode (Recirculation Mode) Setting Pulse Mode 8 : rC Component Remark PuLS Pump Max switching voltage 120VAC, Rated current 2A 1. Select Installer Mode 8:rC 2. Select PuLS Pump operates every 60 minutes.
  • Page 55 Page 55 CHECK VALVE STRAINER SHUTOFF VALVE UNION SERVICE 3-WAY SERVICE 3-WAY GAS BALL VALVE ISOLATION VALVE EXPANSION TANK ISOLATION VALVE W/PRV PORT THERMOSTATIC CIRCULATOR TT24 sensor FAUCET CROSSOVER VALVE PUMP PRESSURE RELIEF VALVE Piping Symbol Legend Note: Piping diagram depicts field supplied Tankless Isolation Service Valves on DCW and DHW piping. Refer to Section 8.1, Flushing the Water Heater on their use.
  • Page 56 Page 56 Setting Title24, On Demand Mode 8 : rC Component Remark Pump, Push Button Max switching voltage 120VAC tt24, OndE (Non Locking) Rated current 2A 1. Select Installer Mode 8:rC 2. Select tt24 or OndE Pump will be operated if the button is pressed longer than 0.5 seconds. 1.If tt24 is selected, pump will be operated as per California’s Building Energy Standards - Title24 regulations.

  • Page 57: Air Handler Mode

    Page 57 4.16 Air Handler Mode Setting Standard Mode 9:AH Component Remark Mixing Valve No electrical connection 1. Select Installer Mode 9:AH 2. Select Std Hot water will be supplied as Air Handler operates. Installation guide...
  • Page 58 Page 58 Setting ECO Mode 9:AH Component Remark Mixing Valve, Flow Switch 1. Select Installer Mode 9:AH 2. Select ECO 3. Select Antl (Anti-Legionella)* → on 4. Select operation time(01 ~ 60 minutes)** * Set the operation/stop time of anti-bacteria function **This will set how long the air handler pump runs each anti-bacteria/legionella cycle.
  • Page 59 Page 59 Sequence of Operation 1. Water heater receives signal from the Room Thermostat and it will control the Air Handler unless the flow switch detects domestic hot water priority. 2. This mode prevents simultaneous operation of DHW and heating to eliminate cold drafts during heating or lower water temperature during showers uses.

  • Page 60: Disposal Of Condensate

    Page 60 4.17 Disposal of Condensate High efficiency, gas condensing water heaters create condensation when operating. This condensation has an acidic pH of approximately 4-5. This should be considered when plumbing the condensate drain. Condensate must be drained in accordance with all local regulations.

  • Page 61: Pressure Relief Valve

    Page 61 4.18 Pressure Relief Valve WARNING An approved ‘Pressure Relief Valve’ must be installed in this installation. The Valve must be Valve Drain an approved ASME HV Relief Valve, installed on the DHW supply line for domestic hot water Pressure Relief loop as close to the unit as possible.

  • Page 62: Dip Switches

    Page 62 4.20 DIP Switches CAUTION There is one set of DIP switches. Scalding Risk: The maximum hot water DIP switches 6 and 7 must be set to OFF when operating supply temperature at Point-of-Distribution the water heater normally. and/or Point-of-Use, anti-scald device/ thermostatic mixing valve at plumbing fixture Dip # Function...

  • Page 63: Wiring Diagram

    Page 63 Page 41 4.21 Wiring Diagram 4.20 Wiring Diagram...

  • Page 64: Ladder Diagram

    Page 64 4.22 Ladder Diagram...

  • Page 65: Electrical Connections

    Page 65 4.23 Electrical Connections Connector Descriptions no. of location and SELV Pin nr. Board Silk type GROUND Power Supply Line Internal Circulation Pump Ignition Transformer HEAT/CP2 Ceramic Heaters HT (120VAC) Gas Valve Unuse Power Supply Neutral 9-12 AC Power COM Line RS485 + RS485 - RS-485...
  • Page 66 Page 66 Connector Description SELV no. of location and type Pin nr. Board Silk Flame Sensor OP.S Outlet Operating Water Temperature Sensor 3,10 DH.S DHW Temperature Sensor 4,11 Inlet Water Temperature Sensor SELV (5VDC) 5,12 BG.S Exhaust Water Temperature Sensor 6,13 ST.S Surface Temperature Sensor...

  • Page 67: Section 5 Control Display And Operation

    Page 67 SECTION 5 Control Display and Operation Control Dial and Buttons Indicator (Green) Function Button Hot Water Temperature Button Display Screen Power ON / OFF Button Dial Button / Enter Button Temperature Unit Select For turning the water heater ON / OFF. Functionalities Buttons PRESS (Tap)

  • Page 68: Lcd Overview

    Page 68 LCD Overview Flame Signal Status and Installer Modes Domestic Hot Water Mode PCB-Display Connection Status External Pump PCB-Display Connect. Status Indicates display and PCB communication is normal Status and Installer mode The Status Mode or the Installer Mode is Active (all parameters) Flame Signal Flame is detected Numeric Display...

  • Page 69: Operating Mode

    Page 69 Operating Mode Operating Mode After the Power is turned on, and/or the Control Display is turned on , the Control Display will go through a ‘Start Up’ checklist and briefly show a sequence of diagnostic codes before entering into the ‘Operating Mode. It will then display the following information. Indicate Example Target DHW Temperature...

  • Page 70: Status Display Mode

    Page 70 Status Display Mode Index Parameter Description A:GA or A:LI Flow Current flow rate value(Li: L/m, GA: GPM) b:Fr Fan RPM Current fan rpm value C:oP Operation temperature Current Operating Temperature D:dH Domestic hot water temperature Current DHW temperature E:Eh Exhaust temperature Current Exhaust temperature...

  • Page 71: Dhw Set Point Change Mode

    Page 71 DHW Set Point Change Mode The LT Series has a built in water flow limiter and will automatically adjust the flow rate up or down based on outlet temperature at the inlet side of the water heater. If...

  • Page 72: Installer Mode

    Page 72 CAUTION Scalding Risk: The use of an anti-scald mixing valve at the hot water outlet (water heater location) can reduce potential for scalding.The maximum hot water supply temperature at Point-of- Distribution and/or Point-of-Use, anti-scald device/thermostatic mixing valve at plumbing fixture or integral to the bathroom fixtures are dictated by the Plumbing Code and Health &...

  • Page 73: Error Mode

    Page 73 Error Mode Flashing Indicate Example Error ‘Er . xx’ will flash Main PCB to Display Connection State NOTE: When communication between the Control Display and the main controller is lost, the will not be displayed.

  • Page 74: Section 6 Error Codes

    Page 74 SECTION 6 Error Codes Error Codes Error *Lockout Error Code Description Possible Remedies Code Type Press the Power button to clear the Error Code. If Error happens again: 1. Monitor the gas pressure to the water heater while in operation. Ensure pressure is between 3.5" and 10.5"...
  • Page 75 Page 75 6.1 Error Codes (continued) Error *Lockout Error Code Description Possible Remedies Code Type This Error Code will clear when the false flame condition is remedied. If Error occurs again: Flame Detected after 1. Check the water heater cover. Ensure it is secure. Flame detection sensor can detect an external Exiting a Flame On light source.
  • Page 76 Page 76 6.1 Error Codes (continued) Error *Lockout Error Code Description Possible Remedies Code Type Press the Power button to clear the Error Code. If Error happens again: 1. Turn power OFF and ON at the main power switch inside the water heater. AGM Error 2.

  • Page 77: Section 7 Troubleshooting

    Page 77 SECTION 7 Troubleshooting Diagnostics Question & Answer Before calling for service, review the following diagnostic steps first for saving time and money. Indicate Indicator Make sure that the ON/OFF button on the Control Panel has been turned ON. If the monitor on the Control Panel is blank, make sure the power cord is plugged and fuses on the main controller in the units are good.
  • Page 78 Page 78 7.1 Diagnostics (continued) Diagnostics and suggested corrective actions This controller is able to record information about the water heater’s condition for the ten previous faults or er- rors. Refer to the ‘Error Code’ section of this Manual, (Section 6). Display Condition Diagnostic...
  • Page 79 Page 79 Display Condition Diagnostic Corrective Action(s) Burner may be operating too hot due to incorrect combustion. Occurs when flame Reset using manual switch. is detected when Reset screen on control FLAME FAULT Check for flame at burner via flame current with there should be no panel.

  • Page 80: Section 8 Maintenance

    Page 80 SECTION 8 Maintenance Annual Startup and General Maintenance Regular Maintenance - Check power source. Make sure that the power cord is correctly connected. After the water heater installation is completed, this The main power line is connected to the manual manual should be placed in safe dry location near switch box inside the Water Heater.
  • Page 81 Page 81 - Cleaning Air Intake Filter - To properly maintain the water heater, you should clean the air intake filter every 3 months. If not, you may encounter combustion issues To clean air intake filter: 1. Press Power button on the control panel to turn off the water heater. 2.
  • Page 82 Page 82 8.1 Annual Startup and General Maintenance (continued) - Flushing the Water Heater 8. Disconnect all hoses. 9. Remove the cold water inlet filter from the water heater Flushing the Heat Exchanger of the water heater is a and clean out any residues. complicated procedure and should only be done by an 10.

  • Page 83: Section 9 Installation Check

    Page 83 SECTION 9 Installation Check Quick View Final check lists Final check : Installation Conditions. Before Installing • Is the Water Heater properly mounted on the wall? - Make sure that there is enough space for installing water and gas line. •...
  • Page 84 Page 84 Final Check List (continued) Final check : Connecting the power supply • Check that the power is 120V AC. • Confirm the polarity of the electrical connection. Final check : Pressure relief valve • Have you installed an approved pressure relief valve on the water heater? •...

  • Page 85: Section 10 Part List

    Page 85 SECTION 10 Part List 10.1 Case Parts IOM Ref Part Number Description ST1224 Exhaust Vent Duct ASSY' ST1225 Exhaust Vent Cap Assy ST1190 Exhaust and Intake Packing O-75 ST1244 O ring P75 10 pcs ST1242 O ring P7 10 pcs ST1226 Intake Inlet Duct ASSY' ST1227...
  • Page 86 Page 86 22-1 O-16 20-2 20-1 20-2 22-1 O-10...

  • Page 87: Fitting Parts

    Page 87 10.2 Fitting Parts IOM Ref Part Number Description ST1106 Hot water Outlet Block ASSY' 23-1 ST1230 Hot Water Temperature Sensor Assy 23-2 ST1218 Block Packing ST1125 Hot Water Outlet Pipe 1 ASSY'(Standard) 24-1 ST1231 Overheat Switch 95℃ Assy 24-2 ST1167 Overheat Switch Bracket...
  • Page 88 Page 88 23-1 24-1 O-18 23-2 23-1 24-1 24-2 23-2 O-18 24-3 24-4 O-15 O-18 O-16 O-15 O-18 O-16 O-16 24-4 24-3 O-15 O-18...

  • Page 89: Fan & Heat Exchanger Parts

    Page 89 10.3 Fan & Heat Exchanger Parts IOM Ref Part Number Description ST1202 Heat Exchanger ASSY'(Standard) ST1134 Exhaust Pipe Upper 33-1 ST1031 Exhaust Temperature Sensor ST1248 Exhaust Packing 5 pcs ST1119 Burner ASSY' 35-1 ST1204 Ignition Rod ASS'Y 35-2 ST1234 Burner High Limit Switch ASSY' 35-3...
  • Page 90 Page 90 33-1 O-18 33-1 O-18 22-2 44-1 44-2 O-22 46-1 35-1 35-2 44-1 O-18 35-2 35-3...

  • Page 91: Section 11 Lt Series Warranty

    Page 91 SECTION 11 LT Series Warranty LAARS HEATING SYSTEMS COMPANY L I M I T E D L T S E R I E S T A N K L E S S W A T E R H E A T E R W A R R A N T Y...
  • Page 92 HOW DO YOU GET WARRANTY ASSISTANCE? Upon discovering a defect or problem, you should: 1. Contact either the Installer or dealer, or 2. Contact us-- LAARS HEATING SYSTEMS COMPANY CUSTOMER SERVICE AND PRODUCT SUPPORT 20 INDUSTRIAL WAY ROCHESTER, NH 03867 1.800.900.9276...
  • Page 93 Customer Service and Product Support: Industrial Way, Rochester, NH, USA 03867 • 603.335.6300 • Fax 603.335.3355 Headquarters: 9 Brigden Gate, Halton Hills, Ontario, Canada L7G 0A3 (905) 203-0600 Fax: (905) 636-0666 www.Laars.com Litho in U.S.A. © Laars Heating Systems 24-05 Document 2182A...
  • Page 94 Customer Service and Product Support: Industrial Way, Rochester, NH, USA 03867 • 603.335.6300 • Fax 603.335.3355 Headquarters: 9 Brigden Gate, Halton Hills, Ontario, Canada L7G 0A3 (905) 203-0600 Fax: (905) 636-0666 www.Laars.com Litho in U.S.A. © Laars Heating Systems 24-05 Document 2182A...

This manual is also suitable for:

Lt199n 1 seriesLt199p 1 series

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