Robertshaw RS5110 - Manual (Page 9)

DEDB = Deadband for auto changeover = the number of degrees that the
room temperature can move away from the active setpoint until
heating or cooling is called for. The larger the deadband the more
the room temperature will vary. This can be from heat to cool or cool
to heat.
HI = High Heat Limit = This is the highest allowed heating setpoint. The
user will not be allowed to set a schedule setpoint or override
temperature higher than this value.
LO = Low Cool Limit = This is the lowest allowed cooling setpoint. The
user will not be allowed to set a schedule setpoint or override
temperature lower than this value.
VAC HEAT = Vacation Heat Setpoint = This is the temperature setpoint for
the heating system when a vacation override has been made active.
VAC COOL = Vacation Cool Setpoint = This is the temperature setpoint for
the cooling system when a vacation override has been made active.
CHECK = Timer to remind the home owner to maintain the filter. Default
setting is off. The timer runs when the system is on and can be set at
0 (OFF) or up to 9900 hours. When the timer expires, CHECK FLTR is
displayed. Press any button to reset and return to the normal display.
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