Honeywell Sundial RF Pack 4 Wireless Enabled Timer and Cylinder Thermostat User Manual

21
FAQ  AND TROUBLESHOOTING
How do I set the time only, if the ST9120C clock is not correct?
Your ST9120C contains an accurate digital clock that is factory set. Should you ever 
need to change the time, just follow this procedure:
a. Move the slider to the DAY/TIME position.
b.  Keep pressing the green 
 button until the message ‘SET THE TIME’ is 
displayed. To change the time, press the   or  buttons until the correct 
time is shown. The message ‘IS TIME OK?’ will be displayed. Press the green  
button...

22
FAQ  AND TROUBLESHOOTING
How reliable is 2-way RF communication?
The 2-way RF communication (also known as wireless communication) used by 
Honeywell is extremely robust and reliable. When installed correctly the Signal 
Strength test feature allows the Installer to locate the system components where 
mutual signal reception is strong. During communication, signals are sent several 
times to ensure receipt, and if any message is garbled, the error detection software 
recognises this and ensures the...

23
FAQ  AND TROUBLESHOOTING
Troubleshooting Guide
This is a quick guide to help you diagnose and cope with possible problems with 
your wireless control system. For further assistance, please contact your Installer.
SymptomPossible CauseRemedy
ST9120C has a blank 
LCD display No power to the 
heating systemCheck that there is power to the 
heating system
Fault in ST9120C
Call Installer
ST9120C indicates the 
system is ON, but taps 
are running with cold 
water.
Temperature controls 
are switched off or...

24
SymptomPossible CauseRemedy
ST9120C shows the 
message ‘SENSOR LOW 
BATT’ and a flashing tap 
symbol CS92A batteries 
are running low on 
power Change the CS92A batteries (see page 
19 for how to do this)
CS92A battery low 
indication (press CS92A 
button and red light 
gives a short flash every 
second 0.1s on, 0.9s off. 
Note: light will switch off 
after approx 1 minute to 
save battery power)
ST9120C shows the 
message ‘NO SIGNAL’ 
and a flashing tap 
symbolCS92A batteries are 
running low on...

25 

2650047645-002 A
CONFIGURATION & SERVICE DATA
Configuration Data (to be completed by Installer)
The tables below are for the Installer to complete to indicate how your ST9120C has 
been configured.
Application
Insert application number as per Installation wiring diagrams:
Configurable FeaturesOptionsFactory 
settingInstaller configured 
(tick box or note value)
ST9120C Configuration - standard
24hr or am/pm clock 
display. am/pm display
24hr display
Display backlight operation. Off
on if button pressed...