1 . . 6
AUTOMANOFF
C M921
DATE
PROG
AUTO
MAN
OFF
Contents
GETTING STARTED WITH THE CM921
STEP 1: Installing the Batteries ......................................... 3
STEP 2: Setting the Date and Time ................................... 4
STEP 3: Running the Built-In Heating Program ................ 4
PROGRAMMING THE CM921
The Built-in Heating Program ............................................ 5
Reviewing the Heating Program ....................................... 5
Modifying the Heating Program ........................................ 5
Disabling / Enabling Time Periods ................................... 7
OPERATING THE CM921
Choosing the Operating Mode ......................................... 8
AUTO mode............................................................. 8
MAN mode .............................................................. 8
OFF mode................................................................ 8
Adjusting the Time ............................................................ 8
During Normal Operation.................................................. 8
Temperature Enquiry ............................................... 8
Temperature Override ............................................. 9
Using the Special Functions ............................................. 9
HOLIDAY Function .................................................. 9
FINE TUNING THE CM921
Changing the User Parameters ...................................... 10
Change the Time Format ....................................... 11
Reset the Built-in Program ..................................... 11
Summer / Winter Time Change ............................. 11
FAQ’s & TROUBLESHOOTING
Trouble Shooting Guide .................................................. 12
Frequently Asked Questions ........................................... 14
WHAT IS A PROGRAMMABLE ROOM THERMOSTAT?
An explanation for householders .................................... 20
Controls Layout
Day / Date Display
Time Display
LoT technology Display
Heating On Indicator
Battery Low Indicator
Temperature Display
Temperature Change Buttons
Temperature Enquiry Button
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Slider Switch
Green OK Button
Program Buttons
Battery Compartment Lid
Battery Compartment
Holiday Function Button
Time Change Buttons
14
15
1 2 3 54 6
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9
10
7
13
12
11
This product and its associated documentation and packaging are protected by various intellectual
property rights belonging to Honeywell Inc. and its subsidiaries and existing under the laws of the
UK and other countries. These intellectual and property rights may include patent applications,
registered designs, unregistered designs, registered trade marks, unregistered trade marks and
copyrights.
Honeywell reserves the right to modify this document, product and functionality without notice.
This document replaces any previously issued instructions and is only applicable to the product(s)
described.
This product has been designed for applications as described within this document. For use
outside of the scope as described herein, refer to Honeywell for guidance. Honeywell cannot be
held responsible for misapplication of the product(s) described within this document.
Manufactured for and on behalf of the Environment and Combustion Controls Division of Honeywell
Technologies Sàrl, ACS-ECC EMEA, Z.A. La Pièce 16, 1180 Rolle, Switzerland by its Authorised
Representative Honeywell Inc.
