THX9321/9421 Prestige
®
IAQ and RF EIM
25
69-2490—03
Delta T Fault Sensitivity is adjustable in the Installer Setup (ISU 13180)
Delta T diagnostics is only for non-zoned forced air systems.
Alerts and diagnostics
Maintain close contact with your customers by providing more comfort and effi-
ciency with alerts and diagnostics. Alerts and reminders can notify customers
when maintenance or service is needed, and display your contact information to
make it easy for them to reach you. The following are only a few of many options.
Check the thermostat's on-screen menus for more.
Alerts and Faults Log
MENU > INSTALLER OPTIONS > DATA LOGS > ALERTS AND FAULTS LOG
The thermostat saves the most recent 25 alerts or faults. It records the date, time,
alert status (snoozed, dismissed, recovered), and diagnostic information to help
you identify and correct problems.
User Interaction Log
MENU > INSTALLER OPTIONS > DATA LOGS > USER INTERACTION LOG
Check this log to find out if a problem was caused by an accidental user error.
The log shows most changes made to thermostat settings, by time and date, and
describes what change was made.
The thermostat records the most recent 250 changes. You can quickly search
them by date and time, or by function. This feature can be turned off if necessary,
so that no user interactions are recorded.
Examples:
*
[date, time]
Heat temperature set to 80° F
*
[date, time]
System mode set to Off
*
[date, time]
Installer setup changed — heating equipment type
Delta T Diagnostics
MENU > INSTALLER OPTIONS > SET UP DIAGNOSTICS
If a discharge and return air sensor is installed, the thermostat can track
system performance over time. It measures this as "Delta T."
This can tell you if the system is performing above or below expected standards
which would normally go unnoticed, and may cause unnecessary energy use. It
can also detect and warn about problems early, before heating or cooling
equipment fails.
The thermostat will measure and record Delta T of the system for each stage
you test. This information can be used to set the proper Delta T fault limits of the
system. When the system operates outside those limits multiple times, a fault is
recorded in the log. If configured to do so, the system will then display an alert to
the homeowner.
69-2490_B.indd 25
7/13/2011 1:42:01 PM
