Honeywell 42011076-003 manual Trouble Shooting Guide, Diagnostic Mode

6) Trouble Shooting

6.1 Trouble Shooting Guide

Symptom (Fault	Possible Cause	Remedy
Message)
The room thermostat	This is normal operation. The receiver box	Using the	button change the
displays the symbol but	cycles the relay on and off for times proportional	temperature setpoint by a few degrees.
the receiver box relay does	to the demand signal (0-100%) from the room	The receiver box should switch the relay
not switch on.	thermostat. The symbol only indicates that the	on after a few seconds delay.
	demand value is greater than 0%.
The receiver box does not	The room thermostat and receiver box are not	Reset the receiver box by pressing and
react to setpoint changes	bound.	holding the push button for 15 seconds.
on the room thermostat.		Then follow the binding / rebinding
		procedure as described in section 5)
		Additional Installation Information.
After the binding procedure	Incorrect or incomplete binding procedure.	Repeat the binding procedure.
the red LED is on and the	Incorrect position of the room thermostat during	Repeat the binding procedure keeping
green one is flashing once
	binding.	approx. 1 m distance between the receiver
every 3 sec on the receiver
		box and the room thermostat.
box.
The red LED on the	The receiver box receives no RF messages from
receiver box is illuminated	the room thermostat:
(Communication loss)	RF signal is blocked due to wrong location of the	Re-locate the room thermostat following
	room thermostat.	instructions in section 2) Installing the
		CM900 Wireless System.
	Room thermostat batteries are exhausted.	Replace batteries in the room thermostat.

6.2 Diagnostic Mode

The CM927/921 room thermostat has a user accessible mode that provides information useful to a remote service person and a means of checking whether the boiler is working. To access this move the slider switch to the OFF position then press and hold the button for 5 seconds. The room thermostat will enter

the user settings mode. Next press and hold the and buttons together. The room thermostat will hold the relay on for 5 minutes and the following information can be viewed on the display by pressing the

or buttons. : model ID, date code (WW/YY) & checksum.

Hereby, Honeywell declares that this CM927/CM921 room thermostat and HC60NG receiver box are in compliance with the essential requirements and other relevant provisions of Directive 1999/5/EC, 73/23EC and 89/336EC.

“Manufactured for and on behalf of the Environment and Combustion Controls Division of Honeywell Technologies Sàrl, Ecublens, Route du Bois 37, Switzerland by its Authorised Representative Honeywell International Inc.”

Honeywell Control Systems Ltd.

Arlington Business Park, Bracknell, Berkshire RG12 1EB

Technical Help Desk: 08457 678999 www.honeywelluk.com

42011076-003 R2

© 2006 Honeywell International Inc.