INTR
ODUC
TION
On-Demand Water Heater Installation Manual and Owner’s Guide
7
INTRODUCTION
• This manual provides information necessary for the
installation, operation, and maintenance of the water
heater. Please read all installation instructions complete-
ly before installing this product. If you have any prob-
lems or questions regarding the installation, operation,
or maintenance, consult the manufacturer or its local
representative.
• This is on-demand, tankless water heater is designed
to efficiently supply hot water when properly sized and
installed.
• This water heater incorporates a recirculation pump.
There are 3 operational modes to choose from:
Recirculation with Dedicated Return line, On-Demand
mode, and Crossover Valve Mode. See page 36 for addi-
tional information.
• These high efficiency models have a built-in secondary
heat exchanger that absorbs latent heat from the exhaust
gas and uses it to increase the efficiency.
• The rating plate lists the model description and is located
on the side of the water heater.
• When the water heater is installed outdoors, attach the
vent cap (100320424) from the manufacturer to the
appliance. (Refer to pp.11, 29, and 30.) Install outdoors
only in areas with mild temperature climate.
6. Water is heated as it circulates through the heat exchang-
ers.
7. Thermistors measure water temperatures throughout the
water heater, the control modulates the gas and water
valves to ensure proper output water temperature.
8. When the tap is turned off, the unit shuts down.
1. A hot water tap is turned on. NOTICE: If recirculation
with dedicated return line configuration is installed, the
recirculation pump activates and the system circulates
water within the loop. Then proceeds to step 3.
2. Water treated by the X3
TM
Cartridge enters the heater.
3. The water flow sensor detects the water flow.
4. The computer initiates the fan motor, opens the gas
valve, and sends a signal to the igniter to create an igni-
tion spark.
5. The gas ignites and flames appear within the burner
chamber.
*This diagram illustrates tankless water heater design concepts only and does not accurately represent the water
heater’s physical description.
Pressure sensor
Exhaust duct
Primary heat exchanger
Igniter
PCB
Secondary heat exchanger
Exhaust thermistor
Ventury
Orifice
Thermistor
Gas valve
Bypass valve
Thermistor
Water control valve
/Flow sensor
Thermistor
Thermistor
X3
TM
Cartridge
Intake
Exhaust
Air adjustment valve
Stepping motor
(Combus�on chamber assembly)
Metal knit burner
Cold water
Gas
Hot water
Return line
Condensate
drain port
Recircula�on pump
Hi-limit
Flame rod
Heater
Igniter rod
Gas solenoid valve
Fan motor
Thermo switch
O.H.C.F
TYPICAL OPERATION SEQUENCE
Summary of Contents for 160X3P
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