Schematic Diagram - A.O. Smith T-M50 ASME Service Manual

5. Schematic diagram

Heat Exchanger
Output
Thermistor
Fan motor
Water
control
valve
Flow sensor
Inlet
Thermistor
Mixing
Thermistor
1. When a hot water tap is opened, cold water enters the T-M50.
2. The water flow sensor detects this water flow and sends this information to computer.
3. The computer initiates fan motor and sends signal to igniter to create ignition spark.
4. The main, proportional, and solenoid gas valves open to allow gas input.
5. The gas ignites and flames appear inside the burner chamber.
6. Water circulates through the heat exchanger and is heated up to the set temperature.
7. Using thermistors to measure temperatures, the computer modulates the gas and water valves to
ensure proper output water temperatures.
8. When the tap is closed, the T-M50 shuts down.
Exhaust
Burner
Gas valve
Cold water
Hot water
inlet
outlet
T-M50 / T-M50 ASME Service manual
Output
Thermistor
120 VAC
Computer board
8
CONFIDENTIAL
Ver. 1.05
Heat Exchanger
Gas
Inlet
Thermistor
Fan motor
Water control
vale
Flow sensor