Introduction - A.O. Smith 910 Installation Manual And Owner's Manual

INTRODUCTION

This manual provides information necessary for the installation, operation, and maintenance of the
water heater.
The model description is listed on the rating plate which is attached to the side panel.
Please read all installation instructions completely before installing this product.
If you have any problems or questions regarding this equipment, consult the manufacturer or its local
representative.
This appliance is an on-demand, tankless water heater. It is designed to efficiently supply endless hot
water for your needs.
The 910 has two heat exchangers. The primary and secondary heat exchangers alternate roles, extend-
ing the life of the 910. (See p. 5.)
The principle behind tankless water heaters is simple:
Water control valve
Flow sensor
3
7
Thermistor
8
1
Hot water inlet
7
*This diagram illustrates tankless water heater design concepts only and does not accurately represent
the water heater's physical description.
1. A hot water fixture is turned on.
2. Water flows through the heater.
3. The water flow sensor detects the water flow.
4. The computer initiates the fan motor and gas valve to let gas flow through the heater and sends a signal to the
igniter to create an ignition spark.
5. The gas ignites and flames appear within the burner chamber.
6. Water is heated as it flows through the heat exchanger.
7. Using thermistors to measure temperatures throughout the water heater, the computer modulates the gas and
water valves to ensure proper output water temperature and hot water outflows.
8. When the fixture is turned off, the unit shuts down.
Exhaust
Heat
6
exchanger
5
Burner
4
7
Fan
Thermistor
4
Computer board
Cold water inlet
2
4
Page
Heat
6
exchanger
5
Burner
3
Igniter
Flow
4
sensor
Fan
Gas valve
7
Thermistor
Gas inlet
4