Laars NEOTHERM NTH Operation manual

User’s Information Doc. 1253A
H2355300A
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.
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.
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
vous trouvez.
• 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.
User’s Information
Manual for
NeoTherm®
Modulating Boiler
Model NTH
Sizes 080-850 MBTU/h
Water Heater
Model NTV
Sizes 150-850 MBTU/h

LAARS Heating Systems

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NeoTherm Boilers and Water Heaters
CONTENTS
Familiarizing yourself to the Laars NeoTherm...................1
FOR YOUR SAFETY,
PLEASE READ THIS BEFORE OPERATING.................2
What to Do If You Smell Gas .............................................2
POUR VOTRE SÉCURITÉ,
LISEZ AVANT DE METTRE EN MARCHE........................2
Que Faire si Vous Sentez une Odeur de Gaz ......................2
Lighting the Unit.................................................................3
Turning Off the Gas to the Unit ..........................................3
Instructions de Mise en Marche..........................................4
Fermeture de l’Alimentation en Gaz...................................4
Shutting Down the NeoTherm............................................5
Restarting the NeoTherm....................................................5
In the Event of Power Failure .............................................5
THE USER INTERFACE AND ON/OFF SWITCH..........6
About Lockouts, Holds, and Alerts...................................10
Care, Inspection, and Service............................................11
Shown without jacket. Internal components will vary slightly between sizes, but the User Interface & On/Off Switch remain the same.
EXHAUST VENT CONNECTION
GAS CONNECTION
ON/OFF SWITCH
USER
INTERFACE
HEAT EXCHANGER
MANUAL SHUTOFF
GAS VALVE
VENTURI
AIR/ GAS
BLOWER
PRESSURE RELIEF VALVE
WATER INLET
WATER OUTLET
AIR INLET CONNECTION
DRAIN VALVE
CONDENSATE TRAP
FAMILIARIZING YOURSELF TO THE NeoTherm®
Sizes available are 080-850 MBTU/h. This illustration is of the 399 MBTU/h

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LAARS Heating Systems
FOR YOUR SAFETY -
PLEASE READ THIS BEFORE OPERATING
WARNING
If you do not follow these instructions exactly, a re or explosion may result,
causing property damage, personal injury or loss of life.
A. This unit does not have a pilot. It is equipped with an ignition device which automatically lights the burner. Do
not try to light the burner by hand.
B. Before operating the unit, check for any smell of gas in the area around it. Be sure to smell next to the oor,
because some gas is heavier than air and will settle near the oor.
C. Use only your hand to turn the handle on the gas valve. Never use tools. If the valve handle will not turn by
hand, don’t try to repair it. Call a qualied service technician. If you force the valve or try to repair it, this
may result in a re or explosion.
D. Do not use this unit if any part has been under water. Immediately call a qualied service technician to inspect
the unit. Any part of the control system or any gas control which has been under water must be replaced.
WHAT TO DO IF YOU SMELL GAS
·Do not try to light any appliance or device that uses gas.
·Do not touch any electrical switch. Do not use any phone in your building.
·Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.
· If you cannot reach your gas supplier, call the re department.
POUR VOTRE SÉCURITÉ,
LISEZ AVANT DE METTRE EN MARCHE
AVERTISSEMENT
Quiconque ne respecte pas à la lettre les instructions dans la présente notice risque un
début d’ incendie ou une explosion entraînant des dommages, des blessures ou la mort.
A. Cet appareil est muni d’un dispositif d’allumage qui allume automatiquement la veilleuse. Ne tentez pas
d’allumer la veilleu manuellement.
B. Avant de faire fonctionner, reniez tout autour de l’appareil pour déceler une odeur de gaz. Reniez près du
plancher, car certains gaz sont plus lourds que l’air et peuvent s’accumuler au niveau du sol.
C. N’utilisez que votre main pour fermer la soupape d’arrêt de gaz. N’utilisez jamais d’outils. Si la poignêe de
la valve ne tourne pas manuellement, ne tentez pas de la réparer. Communiquez avec un technicien de service
qualié. Le fait de forcer ou de tenter de réparer la poignée pourrait causer un incendie ou une explosion.
D. N’utilisez pas cet appareil s’il a été plongé dans I’eau, même partiellement. Faites inspecter I’appareil par un technicien
qualié et remplacez toute partie du système de contrôle et toute commande qui ont été plongées dans I’eau.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ
·Ne pas tenter d’allumer d’appareil.
· Ne toucher à aucun interrupteur; ne pas vous servir des téléphones se trouvant dans le bâtiment.
· Appelez immédiatement votre fournisseur de gaz depuis un voisin. Suivez les instructions du fournisseur.
·Si vous ne pouvez rejoindre le fournisseur, appelez le service des incendies.

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NeoTherm Boilers and Water Heaters
LIGHTING THE UNIT
1. STOP! Read the safety information listed above.
2. Set the thermostat to the lowest setting.
3. Turn off all electric power to the unit.
4 This unit is equipped with an ignition device which automatically lights the burner.
Do not try to light the burner by hand.
5. Remove the front access panel.
6 Turn off the manual gas valve. The valve is off when the valve handle is at a right
angle to the gas pipe.
7. Wait ve minutes to allow any gas to clear. Smell for gas, including the area near
the oor. If you do smell gas, STOP! Follow Step B in the safety information listed
above. If you don’t smell gas, go to the next step.
8. Slowly turn the manual gas valve to “ON.” The handle on the valve will be parallel
to the gas pipe.
9. Replace the front panel.
10. Turn on the electric power to the unit.
11. Set the thermostat to the desired setting.
12. If the unit will not operate, follow the instructions in “Turning Off the Gas to the
Unit” and call your service technician or gas supplier.
Gas inlet
Manual gas valve
shown in the
Off position
TURNING OFF THE GAS TO THE UNIT
1. Before doing any service work, turn off all electric power to
the unit.
2. Set the thermostat to the lowest setting.
3. Remove the front access panel.
4. Turn off the manual gas valve. The valve is off when the
valve handle is at a right angle to the gas pipe.
5. Replace the front panel.
Manual Gas Valve

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LAARS Heating Systems
INSTRUCTIONS DE MISE EN MARCHE
1. ARRÊTEZ ! Lisez les instructions de sécurité sur la portion supérieure.
2. Réglez le thermostat à la temperature la plus basse.
3. Coupez l’alimentation électrique de l’appareil.
4. Cet appareil est dote d’un dispositif d’allumage qui allumera automatiquement le
brûleur. Ne tentez pas d’allumer le brûleur manuellement.
5. Retirez le couvercle avant.
6. Mettez la soupape d’ arrêt de gaz à „OFF”. La valve est en position „OFF” lorsque la
poignée se trouve à angle droit du tuyau de gaz.
7 Attendez cinq minutes an que le gaz se dissipe. Si vous croyez sentir une odeur de
gaz, ARRÊTEZ ! Reportez-vous aux instructions B ci-dessus, sur cette étiquette. S’il
n’y a pas d’odeur de gaz, passez à la prochaine étape.
8. Remettez lentement la soupape d’arrêt de gaz en position „ON”. La poignée sera
parallèle au tuyau de gaz.
9. Replacez le couvercle avant.
10. Rétablissez l’alimentation électrique à l’appareil.
11. Réglez le thermostat à la température désirée.
12. Si l’appareil ne fonctionne pas, suivez les directives relatives à la fermeture de
l’alimentation en gaz et communiquez avec votre technicien de service ou le
fournisseur de gaz.
Entrée
de gaz
Valve de gaz manuel le se
trouvant en position„OFF”.
FERMETURE DE L’ALIMENTATION EN GAZ
1. Coupez toute alimentation électrique à l’appareil si celui-
ci doit faire l’objet d’un entretien.
2. Réglez le thermostat au réglage le plus bas.
3. Retirez le couvercle d’accès au panneau de commande.
4. Mettez la soupape d’arrêt de gaz à „OFF”. La valve est
en position „OFF“ lorsque la poignée se trouve à angle
droit du tuyau de gaz.
5. Replacez le couvercle d’accès au panneau de commande.
Valve de Gaz Manuel

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NeoTherm Boilers and Water Heaters
SHUTTING DOWN THE NEOTHERM
It may sometimes be necessary to shut down the NeoTherm. Here are the steps required to
do this:
1. Switch off the main electrical disconnect switch.
2. Open the front cover and close the main manual gas valve.
3. If freezing is anticipated, drain the NeoTherm. (Also be sure to protect the piping in
the building from freezing.)
The steps listed above may require qualied service personnel.
RESTARTING THE NEOTHERM
It may be necessary to restart the NeoTherm – for example, after a power interruption.
Here are the steps required to do this:
1 Reset any errors using the user interface. See the section on “About Lockouts, Holds,
and Alerts.”
2 Turn up the thermostat to call for heat.
3. In approximately 2 seconds, the blower will operate. Ignition should occur after 35-40
seconds. It may take as long as 2-1/2 minutes.
4. If ignition does not occur, wait 5 minutes and then repeat steps 1 through 3.
5. If, after three attempts, the unit still does not light, shut down the boiler and call your
service technician.
If the unit has been drained, follow these steps:
1. See the “Installation and Operation Manual” for instructions on lling and purging the
unit.
2. Remove the front door. Turn on the gas shutoff valve.
3. Switch on the main electrical disconnect switch. The pump and blower will start, and
the igniter will be energized. After 35 seconds the gas valve will be energized, and
ignition will occur. If ignition does not occur within 2-1/2 minutes switch “off” the
main disconnect switch, wait 5 minutes and switch it “on” again. If after three attempts
ignition does not occur, shut down the unit and call for service.
IN THE EVENT OF POWER FAILURE
The NeoTherm will not operate during an electrical power outage. If there is an extended
power outage with danger of freezing, then the NeoTherm (and all other water systems)
should be completely drained. Before draining the unit, turn off the gas and turn off the
main power switch. When you replace the unit in service, refer to the “Installation and
Operation Manual” for instructions on lling and purging.

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LAARS Heating Systems
On/Off
switch
User Interface
(HMI)
THE USER INTERFACE AND ON/OFF SWITCH
The NeoTherm has two control components:
• the User Interface or HMI (“Human/ Machine Interface”).
• the On/Off switch
The User Interface (HMI) is used to send commands to the boiler controller and to
display operating and setup information sent from the boiler controller.
The drawing below shows the main parts of the user interface (HMI), and the following
table lists the functions of the various parts of the user interface (HMI).
Display
Up/Down
Arrow
buttons
Left/Right
Arrow
buttons
Back button
Info/Install
button
Home button
Round OK button
User Interface (HMI)

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NeoTherm Boilers and Water Heaters
Up/ Down Arrow buttons Use these to go to the choice you want to select in the
display area, then press the round OK button.
Left/ Right Arrow buttons Use these to go to the choice you want to select in the
display area, then press the round OK button.
Back button Use this to go back to the previous display.
Info/ Install button Press this button at any time to go to the sub-menus
that allow you to set up and monitor the controller.
Home button Press this button at any time to go back to the Home
display. (See the section on “Home Display.”)
Round OK button Use the round OK button to conrm a value or action.
Button Functions on User Interface
Home Screen Button
Home Screen
The Home Screen has three sections:
• The upper section of this screen shows the most important operating information. In
this example, the display is showing the system setpoint, the operating temperature,
the outlet and inlet temperatures for the water entering and leaving the boiler, and the
outdoor temperature.
(Note that the ve lines at the top of the screen are customizable, and may be arranged
differently on your system.)
• The central section shows some additional operating and setup information. In this
case, this area lists the boiler name, boiler state, current demand, and the current
password level (the “access status”).
• The lower section shows any current lockouts, holds, or alerts.
When the boiler is operating normally, the boiler controller will display the Home Screen on the
display. Or you can press the Home Screen Button at any time to get to this Home Screen.
Display This area displays several different kinds of
information, including current operating information,
setup parameters, and messages from the system.

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LAARS Heating Systems
Info/Install Button
The Info/Install Button will change the display to show the six sub-menus available.
Info/ Install Screen
• To move from one choice to another, use the Left- and Right-Arrow buttons or the Up-
and Down-Arrow buttons.
• Once you have highlighted the choice you want, press the round OK button.
Here are the functions you can reach from the Info/ Install display screen:
Quick Start This menu gives you an easy way to check or change the
most common settings on the unit.
Login If you want to change a setup value or function, and the
system requires a password, you can enter it here.
Test These parameters let you turn the burner on and off, and
control the fan and pump speeds.
Advanced Setup The sub-menus listed here allow you to set up most of
the functions on the controller.
Diagnostics Use the Diagnostics to check the status of the sensors
and the digital inputs and outputs. The system also re-
cords a history of lockouts and alarms.
Display Setup You can use this option to adjust the contrast of the dis-
play or change the items which appear at the top of the
Home display.

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NeoTherm Boilers and Water Heaters
Quick Start Menu (found in the Info/Install Screen)
Once the unit has been installed and set up, the Quick Start menu provides a simple way
to change the most common settings used in a typical installation.
Quick Start Menu
.
Example - Changing the CH (Central Heat) Setpoint
Changing the CH Setpoint
• On the Quick Start menu, use the Up- and Down-Arrows to go to the line for CH
Setpoint. Press the large OK button to select the line.
• Use the Up- and Down-Arrow buttons to select the value you want.
• Press the round OK button to enter the new value.

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LAARS Heating Systems
ABOUT LOCKOUTS, HOLDS, AND ALERTS
The system responds to three kinds of trouble indications:
• A”lockout” is caused by a serious problem that might involve a safety issue. Once
the controller enters a lockout, the burner will shut down, and will not be allowed
to run again until the cause of the problem is corrected, and you reset the control
system.
• The system may enter a “hold” for a period of time before locking out. This allows
the controller to see if the error becomes resolved prior to the hard lockout.
• An “alert” indicates that some feature of the control system’s operation was not
correct, delayed, or waiting for a response. This does not necessarily indicate a
problem.
If a problem occurs, the system will present a note across the bottom of the screen:
Example - Lockout or Hold Indication
Correct the problem, then press the round OK button to reset the control.
Each error message includes a number. For a more detailed description of each message,
see the “Installation and Operation Manual.”

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NeoTherm Boilers and Water Heaters
GENERAL CARE
Keep the area around the NeoTherm clear and free from combustible materials, gasoline
and other ammable vapors and liquids. Clean the jacket surfaces with a damp cloth
and mild soap. Do not use ammable cleaning materials. Keep the vent terminal free of
obstructions. Do not pile snow against the vent terminal.
ANNUAL INSPECTION AND SERVICE
You should visually inspect the vent pipe once a year. Should any corrosion or leaks
exist, have the affected parts replaced.
Once each year a qualied service agency should conduct a detailed inspection of all ue
product carrying areas of the boiler and vent system. Follow the service instructions in
the “Installation and Operating Instructions Manual” for the Laars NeoTherm.
Caution
Do not use this boiler if any part has been under water.
Immediately call a qualied service technician to inspect the
boiler. Any part of the control system and any gas control
which has been under water must be replaced.
WARNING
If the unit overheats or the gas supply fails to shut off, do
not turn off or disconnect the electrical supply to the pump.
Instead, shut off the gas supply at a location external to the
NeoTherm.
En cas de surchauffe ou si l’admission de gaz ne peut être
coupée, ne pas couper ni débrancher l’alimentation électrique
de la pompe. Fermer plutôt le robinet d’admission de gaz à
l’extérieur de l’appareil.
FOR SERVICE
Contact your installing contractor, gas utility, Laars Heating Systems dealer, or check
www.laars.com for the nearest authorized representative in your area.

Page 12
LAARS Heating Systems
H2355300A
800.900.9276 • Fax [phone] (Customer Service, Service Advisors)
20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax [phone] (Applications Engineering)
1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8 • 905.238.0100 • Fax [phone]
www.Laars.com Printed in U.S.A. © Laars Heating Systems 1209 Document 1253A