Carrier 33CS250-FS Thermostat User Manual

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 111 Catalog No. 533-353 Printed in U.S.A. Form 33CS-13SO Pg 1 105 11-00 Replaces: New
Book 1 4
Tab 11a 13a
Owner’s Manual
Part Number 33CS250-FS and 33CS220-FS
Carrier’s 7-day, commercial, programmable thermostats are
flat, wall-mounted, low-voltage thermostats which maintain
room temperature by controlling the operation of an HVAC
(Heating, Ventilation and Air Conditioning) system. Separate
heating and cooling set points and auto-changeover capability
allow occupied and unoccupied programming schedules for
energy savings.
All thermostats allow up to 3 occupied and one unoccupied
time/temperature settings to be programmed per 24-hour peri-
od. Each thermostat stores programs for 7 independent days.
Batteries are not required. During power interruption the inter-
nal NEVERLOST™ memory stores programmed schedules
for an unlimited amount of time.
Thermostat Display —
The thermostat display is locat-
ed in the center of the thermostat. See Fig. 1. The following in-
formation can be displayed on the screen:
fan setting (FAN ON or blank for Fan Auto operation)
override indication
desired temperature
service filter indicator
time of day
day of the week
schedule period (Occupied 1, 2, or 3; or Unoccupied)
setup indicator (Programming mode)
lock indicator
start/stop indicator (schedule period program mode)
Heat or Cool Indicator — A Heat or Cool indicator is
located in the middle of the thermostat. See Fig. 2. The light
will be red if the thermostat is in Heating mode. The light will
be green if the thermostat is in Cooling mode.
Thermostat Front Panel Buttons — The thermo-
stat has buttons on the front cover which are used to raise or
lower the desired set point, change the mode, program, and
override the current program. See Fig. 2.
ARROW buttons will raise or lower the current desired tem-
perature set point. If the thermostat is in the AUTO or Program
mode, pressing the UP ARROW or DOWN ARROW button
will adjust both the heating and cooling set points. Pressing the
UP ARROW or DOWN ARROW button in Cooling mode
will adjust only the cooling set points. Pressing the UP AR-
ROW or DOWN ARROW buttons in Heating mode will ad-
just only the heating set points.
OVERRIDE BUTTON — The Override button is used to
force the thermostat from Unoccupied mode into the Occu-
pied 1 mode comfort settings. The Override period will be set
at 30 minutes. The thermostat will then return to the program
for that time period. To increase the amount of time in Override
mode, press the Override button again. Thirty minutes of over-
ride time will be added for each time the Override button is
pressed, up to a maximum of 4 hours. After the 4-hour limit
has been reached, press the Override button again to cancel
Override mode.
While in Override mode, the Override icon and the Occu-
pied 1 icon will be displayed on the thermostat. The time of
day and the minutes remaining in Override mode will alternate
on the thermostat display.
The set points are adjustable with the UP ARROW and
DOWN ARROW keys during Override mode.
NOTE: If the thermostat is in Occupied mode and the Override
button is pressed, the thermostat will go into Unoccupied mode
immediately. The thermostat will remain in Unoccupied mode
until the next Occupied start time.
IMPORTANT: Read entire instructions before program-
ming the thermostat.
IMPORTANT: The thermostat has a configurable
security level. If certain functions are not available
(changing set points, changing programming sched-
ules), the thermostat security level may be config-
ured to exclude those functions. Call the installer to
reconfigure the security level.
Fig. 1 — Thermostat Display
Flush-Mounted Flatstat
Commercial Programmable Thermostat