WARNING: Improper installation, adjustment,
alteration, service or maintenance can cause injury
or property damage. Refer to this manual. For
assistance or additional information consult a
qualified installer, service agency or the gas supplier.
Upon completion of the installation, these instructions
should be handed to the user of the appliance for
future reference.
FEATURING: Automatic Variable Power Modulating Gas
Valve with Thermostatic Control
Warning: If you do not follow these instructions exactly, a
fire or explosion may result causing property damage,
personal injury or loss of life.
INSTALLATION AND OPERATING INSTRUCTIONS FOR AUTOMATICINSTANTANEOUS TYPE WATER HEATERS FOR USE WITH NATURAL ANDLIQUEFIED PETROLEUM GAS

WARNING

If the information in this manual is not followed exactly,
a fire or explosion may result causing property
damage, personal injury or death.

FOR YOUR SAFETY

Do not store or use gasoline or other flammable,
combustible or corrosive 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 neighbor’s
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 the gas supplier.
Specifications .................................................... Page 2
Rules for safe operation .................................... Page 4
Locating the Heater ........................................... Page 5
Combustion Air Requirements........................... Page 5
Mounting the Heater .......................................... Page 6
Venting the Heater............................................. Page 6
Gas Connections ...............................................Page 7
Water Connections............................................ Page 7
Safety before lighting the pilot............................ Page 8
Lighting instructions ...........................................Page 8
Information on water temperature...................... Page 9
Maintenance & Service...................................... Page 9
Trouble Shooting ............................................. Page 10
Diagram of AquaStar .......................................Page 13
Components and Parts List ............................. Page 14

TABLE OF CONTENTS

6 720 605 304 PT 862 (12.98)
MODEL 125B LPS and 125B NGS (Thermostatically Modulated)Suitable for water (potable) heating
Intended for domestic hot water with preheated inlet water as with solar hot water. For domestic hot water
applications with cold water inlet, install the 125B model. For constant flow, recirculating applications,
install the 125BL model.