Schematic Diagram - A.O. Smith T-M32 Service Manual

5. Schematic diagram

Heat Exchanger
Hi-limit switch
Output Thermistor
Burner
Water control
valve
Transformer
Flow sensor
Surge box
Mixing Thermistor
1. When a hot water tap is opened, cold water enters the T-M32.
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-M32 shuts down.
P C B
G F I
120 VAC
A C 1 2 0 V
Hot water
T-M32 / T-M32 ASME Service manual
Exhaust
Air-fuel ratio rod
Inlet
Thermistor
Cold water
8
CONFIDENTIAL
Ver. 1.03
Flame rod
O.H.C.F
Igniter rod
Fan motor
Igniter
Gas solenoid valve 3
Gas solenoid valve 1
Gas solenoid valve 2
Main gas valve
Gas proportional valve
Gas