Honeywell CM900 User Manual

Page of 12
CM900 Wireless 
Installation Guide
CM927 / CM921 Wireless Programmable 
Room Thermostat & BDR91 Relay Box
Description
The  Honeywell  CM900  Wireless  (CM927  or 
CM921)  is  a  modern  wireless  programmable 
room  thermostat  based  on  Honeywell’s  proven 
programming  philosophy.  To  further  improve  the 
ease of use, this product includes an extra large 
LCD display with backlighting and LoT Technology 
to assist customers during daily use.
The  CM927/921  room  thermostat  communicates 
with  the  BDR91  Relay  Box  on  an  868MHz  Radio 
Frequency  (RF)  band  to  control  a  single  heating 
system  component  such  as  a  boiler,  pump  or 
zone valve. Neither product will communicate with 
other RF products that use different frequencies or 
communication protocols.
Note:  The  RF  link  between  the  individual  room 
thermostat  (CM927/921)  and  Relay  Box  (BDR91) 
in  system  packs  provided  by  Honeywell  is  pre-
configured  at  the  factory  and  therefore  SHOULD 
be  installed  at  the  same  site.  This  makes  the 
installation process fast and easy, but if products 
from  individual  system  packs  are  separated,  or 
mixed  with  other  pre-configured  system  packs 
during  installations  please  refer  to  section  5.1 
Binding / Rebinding Procedure
 to bind the desired 
units together and allow them to communicate with 
each other.
Table of Contents
Section 
Page
1) Installation Information ................................. 2
2) Installing the CM900 Wireless System ......... 3
 
2.1 Installing the Relay Box
 ................................... 3
  2.2 Installing the Room Thermostat
 ........................ 4
    2.2.1 Power Up
 ............................................... 4
    2.2.2 RF Communication Check
 ........................ 4
    2.2.3 Locating the Room Thermostat
 ................. 5
  2.3 System Check
................................................ 5
3) Basic Operation of the System ..................... 6
 
3.1 Automatic Operation
 ....................................... 6
 
3.2 Temporary Manual Override
 ............................. 6
 
3.3 Communication Loss
 ...................................... 6
4) Installer Mode ................................................. 6
 
4.1 Entering Installer Mode
 ................................... 7
 
4.2 BDR91 Relay Box Fail-Safe Mode Setup
 ............ 7
 
4.3 Using the Room Thermostat for Specific Applications
 .. 8
  4.4 Using the Special Features of the Room Thermostat
 .. 8
  4.5 Installer Parameters Table
 ............................... 9
    4.5.1 Category 1 - Room Thermostat Settings
 ..... 9
    4.5.2 Category 2 - System Settings
 .................. 10
5) Additional Installation Information ............. 11
  5.1 Binding / Rebinding Procedure
 ...................... 11
  5.2 Multi-Zone System
 ........................................ 11
  5.3 Binding an HR80 Radiator Controller
     to the Room Thermostat
 ................................ 11
6) Trouble Shooting .......................................... 12
  6.1 Trouble Shooting Guide
 ................................. 12
  6.2 Diagnostics Mode
 ........................................ 12
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