Robertshaw RS4110 User Manual page 8

CLOC = Clock setting in 12 or 24 hour readings
light = Display backlight always on "Y" or off "n". Also called the
nightlight feature. If the thermostat has been wired to enable this
feature it will be displayed and the setting can be changed.
DIFF = The differential keeps the thermostat from turning on for small
changes in temperature. When in Fahrenheit the range is 0.5 to 3.0
degrees. In Celsius the range is 0.5 to 1.5 degrees. The differential is
factory set to 1.0 F degree (0.5 C degree). This means that whenever
the room temperature is more than 1 F degree (0.5 C degree)
different from the set temperature the system will turn on. If the
system is turning on too often, increase the differential setting. Note
that a larger differential will mean the room temperature changes
more before the system turns on.
DIF2 = SECOND STAGE DIFFERENTIAL = Operates with the first stage to
control a second heating/cooling system. This number will be added
to the first stage differential (See: Two Stage Systems). If the first
stage is running too often lower the settings. This will turn the
second stage on to help the first stage. If both stages are turning on
too often, increase this setting to delay the second stage.
DLY2 = SECOND STAGE DELAY = This timer starts when the first stage
turns on. It resets when the first stage turns off. If this timer expires,
the second stage will turn on (See Two Stage Systems).
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