Great Water, Inc.
14 Arsene Way, Fairhaven, MA 02719
207-729-8500
Carel IR33S Electronic Thermostat Instructions
The Carel IR33 is a very dependable and versatile electronic temperature controller that is well
suited for use with DC marine refrigeration and freezer systems. It has an accurate and easy
to read LED display of the box temperature. It will operate out of the box as a refrigeration
control programmed to display temperature in
°
C and with a defrost timer that will stop the
compressor for 30 minutes every 8 hours. It also has many features that can be programmed
for other applications but for most DC refrigeration applications it is best to stick to the basic
functions described in this condensed set of instructions.
T This symbol on the upper left of the display indicates when the thermostat
“run” relay is closed and the compressor is running.
This symbol will appear on the left of the display when the defrost timer is active
30 minutes every 8 hours – (does not appear if defrost is defeated )
(1)
To change temperature set point:
•Press & hold "SET" for 2 seconds until a flashing number appears in display, then
release “SET”. The flashing number is the present temperature set point.
•Press "UP" or "DOWN" arrows to the desired temperature set point. Suggested starting
set points are 40.0
°
F (4.4
°
C) for a refrigerator & 10.0
°
F (-12.2
°
C) for a freezer.
•Press "SET" to return to temperature display.
Allow sufficient time for the system to settle down between making adjustments.