Honeywell CM921 Installation instructions

1
EN0H 8557 UK07 R0 09/06
CM921
WIRELESS PROGRAMMABLE THERMOSTAT
PRODUCT SPECIFICATION SHEET
The CM921 thermostat is designed to provide automatic time
and temperature control of heating or cooling systems in
villas and apartments.
It can be used as part of a system in conjunction with combi-
boilers, oil-burners and gas fired boilers, circulation pumps,
thermal actuators, zone values and electric heating systems
(<10A). In combination with other CM921 room units and
HC60NG receivers it can be used to control multi-zone
applications (up to 4 zones).
The radio frequency controlled CM921 system pack consists
of a room unit CMT921A and a relay box R6660D (HC60NG).
No wiring to the room unit is required. The installer only
needs to wire the relay box to the controlled device (e.g.
boiler) and mount the room unit in a suitable location where
RF communication is reliable. The CM921 uses reliable RF
communication technology in the 868MHz band.
The CM921 extra large LCD display, dynamic text display
and controls layout are identical to the CM901 ‘wired’
thermostat. The unit is ideal for consumers who want reliable
and precise temperature control from a modern looking,
simple to program and easy-to-use product.
FEATURES
•CM921 can be installed without disrupting your room décor
as no wiring connection is required between the room unit
and the boiler
•Attractive, slim, ultra-modern styling makes it ideal for
location in any type of home
•1-day heating programming
•A dynamic text display on the LCD that gives enhanced
feedback to the user / installer
•LCD Backlighting to illuminate the display for easier viewing
in low light conditions
•Reliable RF communication utilising 868 MHz band with 1 %
duty cycle limit to minimise communication disturbance
•Every room unit can be bound with several relay boxes (e.g.
to control several electric heating panels)
•Armchair programmed
•Holiday button that provides energy savings by reducing
to a constant temperature for 1 to 99 days when people are
on holiday, returning to normal operation (AUTO or
MANUAL) on the day of their return.
•EEPROM memory holds the user program indefinitely
•OFF position has an integral frost protection setting at
minimum 5°C (installer adjustable) so that pipes in the
house will never freeze in winter.
•Communication compatibility with other Honeywell product
such as HR80, HM80 and HCE80.
•CM921 can be used to control a zoning system with up to 4
zones
•Maximum system efficiency and extended boiler life due to
unique zoning system synchronisation
•Automatic Summer / Winter time change adjusts the time
automatically to daylight saving time.
•Standard room units and receiver boxes are used for zoning
applications algorithm
•When used with the table top stand the room unit can be
positioned anywhere in the room where RF communication
is reliable
•24...230V 10A resistive, 3A inductive SPDT relay provides
compatibility with most domestic central heating systems
reducing the need to stock many different models.
•The HC60NG may be surface or wallbox mounted.
•Installer Set-Up Mode allows extra functions to be set at the
discretion of the installer to match the consumer
applications and needs:
•Optimisation
•Pump Exercise
•Upper / Lower Setpoint Limit Adjust
•Temperature offset
•Minimum ON time
•Cycle rate
•Heat / Cool Operation
•Proportional Band Width
•Fail-safe mode for communication loss

CM921 CHRONOTHERM
2
EN0H 8557 UK07 R0 09/06
SPECIFICATIONS
CONTROLS/DISPLAY LAYOUT
ELECTRICAL
Room unit power
supply
:2 x 1.5 V IEC LR6 (AA) Alkaline cells
Battery life :Minimum 2 years
Battery
replacement
:Program retained in EEPROM
Receiver power
supply
:230V AC +10% - 15%, 50Hz
Switch type :SPDT potential free
Output rating :24-230 V AC, 10 A resistive, 3 A inductive
0.6 p.f.
Wiring (receiver
only)
:Cable terminals for mains and relay wiring
for max 2.5 mm2wire
Wire access :from the rear (wall box mounting), right
and bottom
RF
RF operation band :ISM (868.0-868.6) MHz, 1% duty cycle
RF communication
range
:30 m in a residential building environment
RF communication
technology
:short, high rate transmissions to minimise
air time and avoid collisions
Blocking immunity :Receiver class 2 (ETSI EN300 220-1
version 1.3.1)
RF binding method :Factory pre-bound with the room unit.
ENVIRONMENTAL & STANDARDS
Operating
temperature
:0 to 40oC when relay load < 8 A
:0 to 30oC when relay load > 8 A
Shipping & storage
temperature
:-20 to 55oC
Humidity :Humidity range 10 to 90% rh, non-
condensing
IP class :30
Meeting the
following
standards
:EN60730-1(Nov 2000), EN55014-1(1997),
EN55014-2(2000), ETSI EN300 220-3
(2000), ETSI EN301 489-3(2000)
TEMPERATURE CONTROL
Sensing element :100K (@ 25 oC ) NTC thermistor
Control form :Fuzzy Logic Algorithm
Minimum ON
time
10% of cycle time (min one minute),
adjustable to 2 to 5 min (see installer set
up)
Cycle rate :Selectable by application (see installer
set up)
Temperature
control accuracy
:+0.5 K (nominal) @ 20oC, 50% load 3K
Δ/hour
Fail-safe mode :Off or cycling depending on the CM927
system set-up
TIME SETTING/PROGRAMMING
Time display :24 hour or 12 hour AM/PM format
Time keeping
accuracy
:Typically better than 10 minutes per year
Program :1-day with 6 daily time and temperature
level changes
Time setting
resolution
:Time of day - 1 minute
Program – 10 minute steps
Temperature
setting range
:Program : 5 to 35oC in 0.5 oC steps Frost
: 5 oC or equal to lower limit (5
oC to 16 oC). Frost protection does not
work in cooling mode
Room
Temperature
display range
:From 0 oC to 50 oC
Room Unit Layout:
1. Day & Date Display
2. Time Display
3. Dynamic Text Display
(DTD)
4. Burner On Indicator
5. Battery Low Indicator
6. Temperature Display
7. Temperature Change
Buttons
8. Information Enquiry
Button
9. Slider Switch
10. Green OK Button
11. Program Buttons
12. Battery Cover
13. Battery Compartment
14. Holiday Button
15. Time Change Buttons

CM921 CHRONOTHERM
3
EN0H 8557 UK07 R0 09/06
INSTALLER SET-UP
I
n
I
ns
t
a
ll
er se
t
-up we can:
❑Set-up specific applications parameters
❑Enable special features
❑Configure system timing master for the zoning system
To enter the installer set-up mode:
a) Move the slider switch to the OFF position.
b) Press and hold the INFO ibutton and the two program
buttons ‘< >’ together.
c) The unit will display the first parameter of installer
parameter group category 1 (from n.1 to n.19).
d) Press the TEMP or buttons to change the factory
setting. The display will flash indicating that a change has
been made.
e) Press the green OK button to confirm this change and the
display will stop flashing.
f) Press the +button to go to the next parameter.
g) Press the program button >to go to category 2 in the
Installer mode (from n.1 to n.14).
h) To exit the installer mode, move the slider switch to the
AUTO or MAN positions.
Abbreviated Set-Up Description
e.g. Cl = Clock Format
Factory Setting or New Choice
Press TEMP or to change
e.g. 12 = AM/PM Format
24 = 24hr Format
Installer Set-up Number
(Press + or - to change)
e.g. 1= Clock Format
Brief Description of the
Parameter Function.
Specific Applications Setting What do you need to change?
Cycle/
Hour
Minimum
ON time
(in minutes)
Note : All parameters listed below belong to category 2 – System
Parameters (see Installer Parameters Table)
Heating Gas Boilers
(<30KW)
6 1 No changes required
Oil Boiler 3 4 1. Set Minimum ON Time to 4 minutes.
2. Set Cycle/Hour to 3.
Thermal Actuator 12 1 Set Cycle/Hour to 12.
Zone valve 6 1 No changes required.
Air
conditioning
1. Configure the thermostat to allow switching between heating
and cooling modes (set parameter n.4:HC to 1)
2. Set the thermostat accordingly to the required mode of
operation (heating or cooling) by pressing the TEMP or
buttons together for 5 seconds. Modify the cooling program
as required.
Heat Pump/
Air conditioner
3 4 1. Set Minimum ON Time to 4 minutes.
2. Set Cycle/Hour to 3.
Fan coil 6 1 No changes required.

CM921 CHRONOTHERM
4
EN0H 8557 UK07 R0 09/06
Special Features Description Setting
Optimisation
(Variable Start
Time)
The thermostat will adjust the start time in the morning/afternoon
so the desired temperature is reached by the start of the program
period. The system will restrict the start time to a max of 2 hours.
To enable: Set parameter 8:OP
(category 1) to 1.
Heating or Cooling
Operation
This product can be used for heating or cooling applications. If
you select cooling mode the control algorithm and factory default
program will be modified. You can independently modify the
heating and cooling profile.
To enable: Set parameter 4:HC
(category 2) to 1.
Summer/Winter
Auto time change
This feature moves time automatically on the last Sunday of
March and the last Sunday of October. The feature is factory
enabled.
To enable: Set parameter 3:tC
(category 1) to 1.
Temperature Offset If the thermostat is located in a particularly hot/cold location for
reliable signal transmission reasons then the measured/displayed
temperature can be adjusted by +/- 3°C. This is useful if the
homeowner wants the reading to match another appliance
temperature display.
Set parameter 12:tO (category
1) to the required
offset value.
Upper/Lower
Temperature Limit
The normal upper temperature limit of 35°C can be reduced to
21°C to save the homeowner energy. The normal lower limit of
5°C can be increased up to 21°C to protect inhabitants from cold.
Set parameter 6:uL (category 1)
to the desired upper limit.
Set parameter 7:LL (category 1)
Parameter Installer Set-
Up Number /
Abbreviation
(Press + or -
keys to
select)
Factory Setting Optional Setting
Category 1 Parameters – Room Thermostat Settings
Display Description Display Description
AM-PM / 24hr Display 1:Cl 24 24 hr clock display 12 12 hr AM / PM clock display
RESET Time /
Temperature Program
2:rP 1 Time / Temperature profile set
to factory default
Changes to 0 when one of the
time/temp profiles are changed
0
1
Time / Temperature are as programmed
To restore the factory profile set to 1
Automatic
Summer/Winter Time
Change
3:tC 1 Automatic Summer/Winter
Time Change Enabled
0 Automatic Summer/Winter Time Change
Disabled
LCD Backlighting 5:bL 1 Backlighting Enabled 0 Backlighting Disabled
Upper Temperature
Limit
6:uL 35 35°C Upper Temp. Limit 21 to 34 21°C to 34°C adjustment in 1°C steps
Lower Temperature
Limit
7:LL 5 5°C Lower Temp. Limit 6 to 21 6°C to 21°C adjustment in 1°C steps
Optimisation 8:0P 0 Optimisation disabled 1 Optimisation enabled
Temperature Offset 12:tO 0 No offset -3 to +3 -3°C to +3°C adjustment in 0.1°C steps
Proportional Band
Width
13:Pb 1.5 1.5°C Proportional Band 1.6 to 3.0 1.6°C to 3.0°C adjustment in 0.1°C steps
Reset Parameters to
Factory Defaults
19:FS 1 All settings held are the factory
defaults.
Changes to 0 when one of the
parameter values are changed
0
1
Settings are as modified above
To restore the factory profile set to 1
INSTALLER PARAMETER TABLES

CM921 CHRONOTHERM
5
EN0H 8557 UK07 R0 09/06
DIMENSIONS
Parameter Installer Set-
Up Number /
Abbreviation
(Press + or -
keys to
select)
Factory Setting Optional Setting
Category 2 Parameters – System Settings (press the >button to access this category)
Display Description Display Description
Minimum boiler ON
Time
1:Ot 1 1 minute minimum ON time 2 to 5 Selection of 2,3,4 or 5 minutes minimum
ON time
Cycle Rate 2:Cr 6 6 cycles per hour (cph) 3, 9 or12 Selection of 3,9 or 12 cph
Heat / Cool Change 4:HC 0 Disabled 1 Enabled
Pump Exercise 5:PE 0 Pump Exercise Disabled 1 Pump Exercise Enabled
System
Synchronisation
6:Sn 0 Standard operation of the
Room Unit
1 Room unit configured as Synchroniser
Loss of Communication
Instruction
7:LC 0 Relay Off 1 Relay 20% on / 80% off
The following parameters are for the control of other Honeywell Wireless products such as Wireless Underfloor Heating controls and
Wireless Radiator controls. For more information please contact Honeywell sales.
Room Temperature
Sensor Use
8:Su 0 HC60 Control 1,2,3 or 4 1 - HR80/HM80 control with own/remote
sensor (no temperature displayed)
2 - Hr80/HM80/HCE80 control with CM
Sensor
3 - HC60 control and HR80/HM80/
HCE80 control with own/remote sensor
4 – Hr80/HM80/HCE80 control with own/
remote sensor (temperature displayed)
HR80 Window-Open
Function
9:HO 0 Disabled 1 Enabled
HR80 Local Override 10:HL 1 Enabled 0 Disabled
Maximum Flow
Setpoint
11:uF 55 55°C Maximum Flow Temp. 0 to 99 0°C to 99°C adjustments in 1°C steps
Minimum Flow Setpoint 12:LF 15 15°C Minimum Flow Temp. 0 to 50 0°C to 50°C adjustments in 1°C steps
Mixing Value Run Time 13:Ar 150 150 seconds 0 to 240 0 to 240 sec. adjustments in 1sec steps

CM921 CHRONOTHERM
6
EN0H 8557 UK07 R0 09/06
R6660D Relay box CMT921A Room Unit
a
b
WIRING
The R6660D relay box is designed for fixed wiring only and must be installed in accordance with latest l.E.E. regulations.
Ensure the wiring connection to the supply is via a fuse rated at no more than 10 amps and a Class "A" switch (having
contact separation of at least 3 mm in all poles).
IMPORTANT
1. The installer must be a trained service engineer
2. Disconnect the power supply before beginning installation
INSTALLATION
•The CM921 is a radio frequency device and for the best performance should be installed in an open space.
•Leave at least 30cm distance from any metal objects including wall boxes and at least 1 metre from any other electrical equipment
e.g. radio, TV, PC etc.
•Do not mount onto metal wall boxes.
•NOTE: It is recommended that the R6660D relay box is installed before commencing with the room unit installation (refer to the
Installation Guide).

CM921 CHRONOTHERM
Honeywell Control Systems Limited http://europe.hbc.honeywell.com
Newhouse Industrial Estate
Motherwell ML1 5SB
United Kingdom 7
EN0H 8557 UK07 R0 09/06
ORDERING SPECIFICATION
WIRING
NOTE: All wiring must be in accordance
with IEE regulations
Caution: Observe ambient temperature
and current limits (see the receiver box
wiring label)
Description Model Logo Literature Availability Spec Sheet
1-day RF system pack (includes HC60)
1-day RF system pack (includes HC60)
1-day RF system pack (includes HC60)
1-day room unit spare
1-day room unit spare
1-day room unit spare
HC60 Spare
HC60 Spare
HC60 Spare
CMT921A1018
CMT921A1026
CMT921A1042
CMS921B1018
CMS921B1026
CMS921B1042
R6660D1017
R6660D1025
R6660D1041
Honeywell
Honeywell
Honeywell
Honeywell
Honeywell
Honeywell
Honeywell
Honeywell
Honeywell
French & Dutch.
French
English (UK)
French & Dutch.
French
Spanish
French & Dutch.
French
English (UK)
Sep 06
Oct 06
Oct 06
Sep 06
Oct 06
Oct 06
Sep 06
Sep 06
Sep 06
ENOH8557
ENOH8557
ENOH8557
ENOH8557
ENOH8557
ENOH8557
ENOH8557
ENOH8557
ENOH8557