Bosch AquaStar Indoor Natural Gas Tankless Water Heater with Vent Hood #125 - 125B_manual.pdf

I NSTALLATION AND OPERATI NG I NSTR UCTIONS FOR AUTOMATIC INSTANTANEOUS TYPE WATER HEATERS FOR USE WITH NATURAL AND LIQUEFIED PETROLEUM GAS MODEL 125B LP and 125B NG (Flow Modulated) Suitable for heating potable water only Not approved for space heating purposes Intended for variable flow applications with steady cold water inlet temperatures only

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.

6 720 607 030 US (05.12) AL

TABLE OF CONTENTS

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. In the Commonwealth of Massachusetts this product must be installed by a licensed plumber or gas fitter.

Specifications ....................................... Page 2 Rules for safe operation ..................... Page 4 Locating the Heater ............................ Page 4 Combustion Air Requirements .......... Page 5 Mounting the Heater ........................... Page 6 Venting the Heater .............................. Page 7 Gas Connections .............................. Page 10 Water Connections ........................... Page 12 Safety before lighting the pilot ....... Page 12 Lighting instructions .......................... Page 13 Setting water temperature ............... Page 13 Maintenance & Service .................... Page 13 Trouble Shooting ................................ Page 14 Diagram of AquaStar ........................ Page 19 Components and Parts List ............ Page 20 Warranty ............................................. Page 22

This well engineered, gas water heater has all the features a water heater should have: It operates on the principle of heating water instantaneously “on demand”. When a hot water faucet is opened, cold water flows through the coils of the heat exchanger in the Aquastar. This same flow opens the gas valve, and the burners are ignited by the pilot flame. The heat exchanger coils absorb the heat generated by the burners and transfer heat to the water. When the hot water faucet is shut off, the gas valve automatically closes and the burners turn off. Your hot water faucet is an ignition key to turn on the water heater, giving you control over your hot water energy use. Each time you turn off your hot water faucet, you also shut off the water heater.

AquaStar 125B LP and 125B NG Specifications

Gas Input max.: 117,000 Btu/hr min.: 28,000 Btu/hr Water Connection 1/2” Thread fitting NPT H x W x D 29 3/4” x 18 1/4” x 8 3/4" Vent 5” Gas Connection 1/2” NPT thread Min. Water Pressure 18 Psi at 4 GPM

FEATURES

Max. Water Pressure 150 Psi

- High Quality Materials for Long Working Life.

Shipping Weight 42 LB

- Copper heating coils for endless supply of hot water.

Net Weight 39 LB

- Burner output proportional to hot water flow demand for maximum energy efficiency.

1.8 GPM at 90° rise 3.7 GPM at 45° rise

- Safety thermocouple at pilot burner. Min. Water Flow 1/2 gal/min - Automatic overheating protection shut-off sensor. - Flue gas safety device.

LP GAS Supply Pressure (before Aquastar regulator)

min. 11” W.C. max.14” W.C.*

Required LP GAS pressure at inlet tap while Aquastar is operating:

10.5” W.C