Lux Products P521Ub Thermostat User Manual


 
TO RESET THE FILTER USAGE COUNTER: Move the Set Slide switch to the “AIR
FILTER” position. The three small digits at the top of the screen tell you the
quantity of filter days remaining. Press both the UP and DOWN buttons together,
and the usage counter will return to the beginning of the value that it originally
started counting from. Refer to the previous paragraph, should you wish to
change the starting value for the filter monitor. Return the Set Slide switch to
the RUN position when you are finished.
HARDWARE RESET: The Hardware Reset button (labeled “HW
RST”) is a small round push button that is located in the
middle of the circuit board, just below the battery holder.
Pressing this button will cause the LCD display screen to
become fully populated, the heating and cooling load relays to
cycle off, and will perform an internal system check of the
thermostat components. If your thermostat appears to be acting in an erratic
manner, pressing the Hardware Reset button may remedy this behavior. The
temperature programs are not erased when a hardware reset is performed,
however the clock will have to be changed to match the current day and time.
SOFTWARE RESET: A Software Reset is used to erase ALL heating and cooling
temperature programs, and to return all user-adjustable software settings back
to their original factory default values. To perform a Software Reset, first ensure
that the thermostat’s Keypad Lockout is not enabled and then move the System
Mode switch to the OFF position. Press and hold the UP, DOWN, and NEXT
buttons all together for at least 5 seconds. The LCD display screen will become
fully populated (let go of buttons at this point), and than return to normal. The
clock will have to be changed to match the current day and time.
COMPRESSOR PROTECTION BYPASS: This optional feature permits the installer
or service technician to temporarily disable the built in compressor protection
delays. This is most useful for diagnosing and testing the heating and cooling
systems after installation is complete, and should not be used during normal
operation. To activate this feature, press and hold both the NEXT and HOLD
buttons, while also perform a single press of the Hardware Reset button (the LCD
display screen will become fully populated). Continue to hold the NEXT and
HOLD buttons until the LCD display screen returns to normal. All compressor
protection delays (in all modes of operation) will be disabled for 5 minutes. After
the 5-minute duration has expired, the thermostat will return to normal operation
automatically.
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HW RST