Laars LT Series Installation And Operation Instruction Manual
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Laars LT Series Installation And Operation Instruction Manual

Wall-mounted, modulating gas condensing water heater with recirculation pump
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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 with
Recirculation pump
Model
•
Natural Gas (NG) - Factory Configuration
•
Propane (LP) - Factory Configuration
WARNING
LT199NRX1 / LT199PRX1
(199,000 BTU/hr)
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
• 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 2192A
GAZ:

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Summary of Contents for Laars LT Series

  • Page 1 Installation and Operation Instructions Document 2192A Installation and Operation Instructions for LT Series Wall-Mounted, Modulating Gas Condensing Water Heater with Recirculation pump Model LT199NRX1 / LT199PRX1 (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

    4.9.5 Installing the Common Vent System with PVC or CPVC venting materials (U.S. Installation Only) ..38 10.3 Fan & Heat Exchanger Parts ......91 4.9.6 PVC Common Venting Componets Configuration ..43 SECTION 11 LT Series Warranty 4.9.7 Polypropylene Common venting ......43 4.10 Gas Supply and Piping ........44...

  • Page 3: Section 1 Product Accessories

    This manual provides information necessary for the 2) In Canada, CSA B149.1 "Natural Gas and Propane Installation installation, operation, and maintenance of the LT Series. Code" and with the requirement of the local utility or other All application and installation procedures must be read and authorities having jurisdiction.

  • 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 LT199NRX1 / LT199PRX1 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 - [LT199NRX1 / LT199PRX1] 6.9" [175mm] 5.8" [148mm] 4.6" [117mm] 17.3" [440mm] 2.4" [62mm] 3.2" [81mm] 8.9" [226mm] 6.4" [163mm] Description Size Exhaust 2" PVC Air Intake 2" PVC Hot Water 3/4" NPT Condensate 1/2" NPT Recirculation Return Connection 3/4"...

  • Page 7: Names Of Components

    Page 7 Names of Components [LT199NRX1 / LT199PRX1] Name of Component Name of Component Vent Pipe Collar Cold Water Inlet Combustion Air Intake Assembly Gas Inlet Control Board (PCB) 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 - The bottom of the vent and air intake terminal must ULCS636) be at least 12" above the normal snow line. In no case should they be less than 12" above grade - 2ZDE_87 or 3ZDE_87 (2"...

  • Page 19: Locations For Vent Pipe Terminal

    Page 19 Locations for Vent Pipe Termination 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 Exhaust (2” or 3”) 12”...

  • 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 (LT199NRX1 / LT199PRX1) 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 - Recirculation with multiple LT199NXX1 Units...

  • Page 30: Electrical

    Page 30 4.9.2 Electrical Wiring Connections for Cascade Components Needed : FT1861: (1 per unit) Cascade Communication Cable with Ending Resistor. Example. If you are cascading 2 tankless units, you will need 2 X communication cables and you will only need one of the included ending resistors. To CN1 RS-485 Primary Connector.

  • Page 31: Cascade Programming

    Page 31 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 2 parameters that need to be programmed on the leader unit before moving on to the follower units. 13:cn - (Unit ID of the cascade system) Sets Cascade Address.
  • Page 32 Page 32 B. To Program the Tankless Water heater Follower: Now move over to the follower unit and perform only 13:cn – (Unit ID of the cascade system) to each of the following units. 13:cn - (Unit ID of the cascade system) Sets Cascade Address. The Follower should always be addressed 02 or higher number if LT199NXX1 is cascaded.

  • Page 33: Common Vent System (U.s. Installation Only)

    Page 33 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 34 Page 34 • 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 35 Page 35 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 36 Page 36 • 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 37 Page 37 ■ Setting the vent type 1. Turn OFF the Power to the Display Control. 2. Then, with the power OFF. Press and HOLD the button to get into the Installer Mode. 3. Rotate the Dial until you get to 15:Vt Tap the Dial to enter into that Parameter.

  • Page 38: Installing The Common Vent System With Pvc Or Cpvc Venting Materials (U.s. Installation Only)

    Page 38 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 39 Page 39 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 40 Page 40 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 41 Page 41 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 42 Page 42 ■ 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 43: Pvc Common Venting Componets Configuration

    Page 43 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 44: 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 45 Page 45 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 46 Page 46 Natural Gas piping installation. The Water Heater is The Water Heater is recommended to be recommended to be the first appliance to the first appliance to be connected to the be connected to the gas supply line. gas supply line. Union Other appli Connection...

  • Page 47: Gas Conversion

    Page 47 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 48: Gas Setup And Adjustment

    Page 48 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 49: 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 50: Plumbing Guidelines

    Page 50 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 51 Page 51 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 52: Re-Circulation Setting

    Page 52 4.15 Re-Circulation Setting Select Water Heater Mode (LT199NRX1, LT199PRX1) Setting Requirement Performance Mode Description Wait Time Dedicated Energy Hot Water 9:RC Accessory Water Return Line Savings Temperature Savings Same as regular tankless Recirculation water heaters. Hot water without Internal Itnl Better...
  • Page 53 Page 53 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 54 Page 54 Recirculation Mode [ External Mode] · Provides most comfortable option. Maintains consistent hot water availability during specified times. · Timer can be manually customized or programmed to automatically learn daily usage patterns. · Ability to optimize by using Installer Mode function 10:RT to adjust loop temperature for maximum comfort and safety.
  • Page 55 Page 55 Recirculation Mode [ On Demand(tt24) Mode] · Provides best energy savings option · Designed to meet California Title 24 requirements. · Recirculation will only operate when the push button switch is pressed. Hot water will not be available immediately.
  • Page 56 Page 56 Recirculation Mode [ Crossover(CrOS) Mode] · Provides recirculation option for homes without a dedicated return line by utilizing the cold water line as a return line. · Timer can be manually customized. · In order to prevent hot water from being supplied into the cold water line, the thermal element in the crossover valve will close at 95°F.

  • Page 57: Air Handler Setting

    Page 57 4.16 Air Handler Setting 1. Water heater receives signal from the Room Thermostat and it will control the Air Handler unless the flow detects domestic hot water. 2. This mode prevents simultaneous operation of DHW and heating to eliminate cold drafts during heating or lower water temperature during showers uses.

  • Page 58: Setting The Display Panel

    Page 58 4.17 Setting the Display Panel Setting the internal Clock ► To use the ‘Recirculation Timer’, the device’s internal clock should be adjusted to the current time. Clock settings can be set in the ‘User Mode’. See Section 5.2 for Timer Setting. [ To enter ‘User Mode’...
  • Page 59 Page 59 To set the recirculation mode (Internal, External, On-Demand, Crossover) 1. Press the 'Power Button' OFF. ('Display Screen' will be blank) 2. Press and hold the ‘Function Button’ for approximately 5 seconds to get into the ‘Installer Mode’. 3. ‘1:EH’ oFF will appear on the ‘Display Screen’. Rotate the dial clockwise until ‘9:RC’...

  • Page 60: Disposal Of Condensate

    Page 60 4.18 Disposal of Condensate High efficiency gas condensing Water Heaters create condensation when operating. Condensation has acidic (pH) of approximately 4-5. Condensate must be drained in accordance with all local regulations. Follow your local code with regards to the disposal of condensation. One of 3 disposal methods must be followed 1.

  • Page 61: Pressure Relief Valve

    Page 61 4.19 Pressure Relief Valve WARNING An approved ‘Pressure Relief Valve’ must be installed in this installation. The Valve must be an approved ASME HV Relief Valve, installed on the DHW supply line for domestic hot water loop as close to the unit as possible. (Valve size 3/4˝, maximum 150psi).

  • Page 62: Electrical Wiring Connections

    Page 62 4.20 Electrical Wiring Connections WARNING Do not disconnect the power supply when the Install wiring and electrically ground Water unit is in normal operation. Heater in accordance with authority having Damage caused by freezing is not covered under jurisdiction or in the absence of such the warranty.

  • Page 63: Dip Switches

    Page 63 4.21 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 64: Wiring Diagram

    Page 64 4.22 Wiring Diagram...

  • Page 65: Ladder Diagram

    Page 65 4.23 Ladder Diagram...

  • Page 66: Electrical Connections

    Page 66 4.24 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 67 Page 67 Connector Description no. of location and SELV Pin nr. Board Silk type 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 68: Section 5 Display Panel And Operation

    Page 68 SECTION 5 Display Panel and Operation Control Dial and Buttons Indicator (Green) Function Button Hot Water Temperature Button Display Screen Power ON / OFF Button Dial Button / Enter Button Recirculation Timer For turning the water heater ON / OFF. Functionalities Buttons PRESS (Tap)

  • Page 69: Lcd Overview

    Page 69 LCD Overview Combustion Icon PCB-Display Connection Status Temperature Unit 1. Press the ‘Recirculation Timer Button’ while power of the External Recirculation Icon Lock Mode 2. If [Act] is flashing, select the [SEt] by turning the ‘Dial Bu display screen is turned on. Hot Water Operating Icon High Temperature Icon Vacation Mode Icon...

  • Page 70: Operating Mode

    Page 70 Operating Mode Operating Mode After the Power is turned on, and/or the Display Panel is turned on , the Display Panel 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 71: Status Display Mode

    Page 71 Status Display Mode Index Description Main HotF DHW flow rate value by On demand A:GA rCLF Circulated water flow rate value by Internal pump b:Fr Current Blower rpm C:oP Heat Exchanger temperature D:dH DHW Hot outlet temperature E:Eh Exhaust gas temperature F:In Cold Inlet temperature...

  • Page 72: Dhw Set Point Change Mode

    Page 72 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 73: Installer Mode

    Page 73 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 74: Error Mode

    Page 74 Error Mode Flashing Indicate Example Error ‘Er . xx’ will flash Installer icon NOTE: When communication between the Display Panel and the control board is lost, the will not be displayed.

  • Page 75: Section 6 Error Codes

    Page 75 SECTION 6 Error Codes Error Codes Error Error Code *Lockout Possible Remedies Code Description 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 14"WC.
  • Page 76 Page 76 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 happens 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 Soft Lock light source.
  • Page 77 Page 77 6.1 Error Codes (continued) Error Error Code *Lockout Possible Remedies Code Description Type "Press the Power button to clear the Error Code 1. Check if dip switch MAX Fire setting is ON. Switches 6 and 7 should be OFF for normal operation. 2.
  • Page 78 Page 78 6.1 Error Codes (continued) Error Error Code *Lockout Possible Remedies Code Description Type This Error Code will clear when the condition is remedied. If Error happens again: Poor Communication Soft Lock 1. Check connections from main control to display panel. 2.

  • Page 79: Section 7 Troubleshooting

    Page 79 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 Display Panel has been turned ON. If the monitor on the Display Panel is blank, make sure the power cord is plugged and fuses on the control board in the units are good.
  • Page 80 Page 80 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 errors. Refer to the ‘Error Code’ section of this Manual, (Section 6). Display Condition Diagnostic...
  • Page 81 Page 81 Display Condition Diagnostic Corrective Action(s) Burner may be operating too hot due to FLAME FAULT Occurs when flame Reset using manual switch. incorrect combustion. is detected when Reset screen on display there should be no panel. Check for flame at burner via flame current with flame (Power button) burner off.

  • Page 82: Section 8 Maintenance

    Page 82 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 83 Page 83 - 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 display panel to turn off the water heater. 2.
  • Page 84 Page 84 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 and clean out any residues. a complicated procedure and should only be done 10.

  • Page 85: Section 9 Installation Check

    Page 85 SECTION 9 Installation Check Quick View Final check lists Before Installing Final check: Installation Conditions. - Make sure that there is enough space for installing • Is the Water Heater properly mounted on the wall? water and gas line. •...
  • Page 86 Page 86 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 87: Section 10 Part List

    Page 87 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 88 Page 88 15-1 15-1 O-10 O-75 O-16 O-20 17-1 20-1 O-16 20-1 17-1...

  • Page 89: Fitting Parts

    Page 89 10.2 Fitting Parts IOM Ref Part Number Description ST1106 Hot water Outlet Block ASSY' 22-1 ST1230 Hot Water Temperature Sensor Assy 22-2 ST1218 Block Packing ST1107 Hot Water Outlet Pipe 1 ASSY'(Premium) 23-1 ST1231 Overheat Switch 95℃ Assy 23-2 ST1167 Overheat Switch Bracket...
  • Page 90 Page 90 26-1 O-15 O-18 O-18 26-1 O-18 O-18 26-1 O-16 O-15 O-16 22-1 23-1 O-18 23-1 22-1 23-2 22-2 O-16 O-18 O-15 O-16 O-18 O-16...

  • Page 91: Fan & Heat Exchanger Parts

    Page 91 10.3 Fan & Heat Exchanger Parts IOM Ref Part Number Description ST1118 Heat Exchanger ASSY'(Premium) ST1134 Exhaust Pipe Upper 39-1 ST1031 Exhaust Temperature Sensor ST1248 Exhaust Packing 5 pcs ST1119 Burner ASSY' 41-1 ST1204 Ignition Rod ASS'Y 41-2 ST1234 Burner High Limit Switch ASSY' 41-3...
  • Page 92 Page 92 41-1 41-2 41-3 39-1 39-1 O-18 O-18 22-2 41-2 O-22 50-1 52-1 50-2 50-1 O-18...

  • Page 93: Section 11 Lt Series Warranty

    Page 93 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 94 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 95 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 2192A...
  • Page 96 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 2192A...
  • Page 97 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 2192A...
  • Page 98 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 2192A...

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