State 520 - Manual (Page 3)

Introduction
3
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Page
INTRODUCTION
*This diagram
illustrates tankless
water heater design
concepts only and
does not accurately
represent to the water
heater’s physical
description.
 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 of
the water heater.
 Please read all installation instructions completely before installing this product.
 If you have any problems or questions regarding this equipment, consult with the
manufacturer or its local representative.
 This equipment is an on‐demand, tankless water heaters designed to efficiently supply
endless hot water for your needs.
 The principle behind the water heater is simple:
1. A hot water tap is turned on.
2. Water enters the heater.
3. The water flow sensor detects the water flow.
4. The computer automatically ignites the burner.
5. Water circulates through the heat exchanger and then gets hot.
6. The computer will modulate the gas supply valve and water flow to produce the right
amount of hot water at the correct temperature.
7. When the tap is turned off, the unit shuts down.
 The water heater is high efficiency models with an in‐build secondary heat exchanger
that absorbs latent heat from the exhaust gas.
Burner
Condensate
drain port
Secondary heat exchanger
Thermistor
Thermistor
Gas Valve
Flow sensor
Water control valve
Bypass valve
Intake port Exhaust
Fan motor
Primary heat
exchanger
Thermistor
PCB
Hot Water Outlet Cold Water Outlet
Gas