General Operation; How The Water Heater Operates; Sequence Of Operation; Access Modes - A.O. Smith XWH 150 Service Handbook

GENERAL OPERATION

HOW THE WATER HEATER OPERATES

The XP water heater uses an advanced stainless steel heat exchanger and an electronic control module that
allows fully condensing operation. The blower pulls in gas and air and pushes fl ue products out of the water
heater through the heat exchanger and fl ue piping. The control module regulates blower speed to control
water heater fi ring rate. The gas valve senses the amount of air fl owing into the water heater and allows only
the right amount of gas to fl ow.

SEQUENCE OF OPERATION

Table 1 shows control module normal sequences of operation for water heating operation.

ACCESS MODES

User
The user can adjust tank target temperatures by accessing the Tank Temperature using the MENU option on
the Touch Screen Display. The date and time can also be changed.
Installer
Most parameters are available only to the installer, accessible by entering the installer password (5309).

SAVING PARAMETERS

Refer to the Parameter Table - Table 4 on Pages 14 and 15 of this Service Handbook.
To save parameters and exit programming:
After setting or changing the parameters touch the ACCEPT option on the Touch Screen Display.
To enter a parameter and continue programming:
Use the +/ - options for setting the required parameters or the Up/ Down arrows on the Touch Screen Display
to access and make appropriate changes. Remember to ACCEPT the changes when fi nished programming
in order to save the changes made.
Servicing should only be performed by a Qualifi ed Service Technician
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