Honeywell Sundial RF Pack 3 Wireless Enabled Programmer and Thermostats User Manual

							21
DT92E OPERATING INDICATORS
Low Battery Indicator / Battery Replacement
The battery symbol will start 
to flash if the battery power is 
running low. From this point, 
there will be a minimum of 4 
weeks before the product will 
cease to function.
Batteries are accessed by 
unclipping the front cover at the 
bottom. Note battery polarity. 
Reverse process to refit front 
cover.
Use 2xLR6 (AA) alkaline 
batteries only. 
Immediately on power up, DT92E will try to communicate and synchronise with 
ST9420C. This process may take up to 4 minutes, and will be indicated by the word 
‘Sync’ on the DT92E display.
RF Communications Indicator
A brief flash of the RF symbol  indicates the DT92E 
has been communicating with the other system 
controls.
Lockout
Your DT92E works in conjunction with the ST9420C 
time control. If the timer is set to OFF or CONT it may 
not be possible to override it from the thermostat 
and this is indicated by the lockout symbol 
. To 
switch the heating on you must go to the timer and 
set the Mode to AUTO, ONCE, or CONT.
2 x LR6 AA Alkaline
1
2 
						

							22
DT92E ENERGY SAVING ECO FEATURE
The ECO button allows you to change to a lower, energy saving set temperature for 
a period of your choice, from 1 to 24 hours. This temperature is pre-set in the DT92E 
Installer Mode, but you can adjust this to any temperature you want when ECO mode 
has been activated. The default ECO temperature is 18°C.
At the end of the time period, the thermostat will return to its original set 
temperature.
Entering ECO Mode and Setting 
the Energy Saving Time Period
Press the green ECO button to enter ECO 
mode. The word ECO will appear on the 
display and the thermostat will allow you to 
set the number of hours you want to be at 
the new set temperature.
Use the 
 and  buttons to set the hours, 
up to a maximum of 24 hours.
Please note – ECO mode is not accessible 
in Holiday mode or if Service shutdown 
has occurred.
What Happens in ECO Mode?
In ECO mode, the display will show a 
countdown of the remaining time (hours 
and minutes) in ECO mode, identified by 
the hourglass symbol. The display will 
alternate every 5 seconds to show the 
current room temperature.
When in ECO mode, pressing the 
 or  
buttons will adjust the set temperature for 
the remainder of the ECO time period. 
5 s 5 s
5 s
1,2,3,4....,24hr 
						

							23
DT92E ENERGY SAVING ECO FEATURE
FINE TUNING YOUR  DT92E
Changing the DT92E Installer Parameters
The DT92E has a special Installer Mode where some features can be adjusted to suit 
your lifestyle or preferences – these are called Installer Parameters, and are listed in 
the table below, along with a description of the options that are possible.
Your installer should set this up for you to suit your application (see \
CONFIGURATION 
& SERVICE DATA section). However, you may wish to alter some of the settings 
yourself, and this section shows you how to do this.
INSTALLER 
PARAMETERParameter
Default 
Value Options
Description
Temperature 
measurement offset t0
0-3 to 3 K Offset to measured 
temperature
Upper setpoint limit uL3521 to 
35°C Upper set temperature 
limit in °C
Lower setpoint limit LL55 to 21°C Lower set temperature 
limit in °C
Energy saving ECO 
setpoint ES
185 to 35°C Energy saving ECO set 
temperature in °C
Reset parameters 
to factory settings FS
10, 1Parameter will be set to 0 
if any of the other param-
eter values have been 
changed. Set to 1 to get 
back to factory settings.
How to Exit ECO Mode
To exit ECO mode, simply press the green 
ECO button again. ECO will disappear 
from the display and the thermostat will 
control to its previous set temperature. 
						

							24
To Enter Installer Mode:
a. Hold the 
 button for 2 seconds until DT92E is in standby mode.
b. Hold 
 and  buttons for 3 seconds until the word ‘Inst’ appears on the 
display.
c.  Press the 
 button.
The first parameter is now ready to be changed.
To Select a Parameter:
Use the 
 and  buttons to move from one parameter 
to the next. Stop at the Parameter you wish to change.
To Change a Parameter:
Use the standby button to select the parameter value, then the 
 and  buttons to 
change the value. Confirm the change by pressing the  button again to take you 
back to the parameter.
To Exit Installer Mode:
Hold the 
 button for 3 
seconds to exit Installer 
Mode.
Note: The Installer Mode will 
exit automatically after 10 
minutes if  no adjustments 
have been made in this 
time.
FINE TUNING YOUR  DT92E
3 s
3 s
2 s 
						

							25
OPERATING YOUR CS92A HOT WATER THERMOSTAT
Basic Operation
Your CS92A consists of a sensor element that 
is strapped to the metal surface of the hot 
water cylinder and a wireless transceiver box 
that is normally mounted on a wall surface 
apart from the cylinder. The transceiver 
communicates with the ST9420C programmer 
and regularly sends the hot water temperature 
measurement to it.
Battery Replacement
The CS92A batteries should last for a minimum of 2 years. Well before they run out, 
CS92A will communicate with ST9420C and it will show the message ‘SEN\
SOR LOW 
BATT’ whilst also flashing the tap symbol.
Batteries are accessed by 
unclipping the front cover 
at the bottom. Note battery 
polarity. Reverse process 
to refit front cover.
Use 2xLR6 (AA) alkaline 
batteries only. 
Error Indications
To save battery power, CS92A will indicate 
error conditions on the LoT™ Display of 
ST9420C. It is possible to view the CS92A sta-
tus by pressing the button on the transceiver 
box. The lights underneath this button will 
provide feedback as shown in the table. Go 
to the FAQ AND TROUBLSHOOTING section 
for more information.
1
2
Sensor elementTransceiver
Green LightRed Light Status
On Flashes up to 5 times in 
succession, then repeats
Everything is OK, red light shows signal 
strength - press button again to exit
OffFlashes 0.1 s on, 0.9 s off Battery low condition, replace batteries
Off Flashes 0.5 s on, 0.5 s off Sensor error, check sensor connection
Off On continuously Loss of communications 
						

							26
BDR91T Controls Layout
Automatic Operation
The BDR91T relay box simply switches the boiler 
on and off according to a wireless signal it receives 
from the ST9420C. It is mainly used when the boiler 
is installed  in a remote location where it may be 
difficult to run wires direct from the timer. The green 
light indicates the status of the relay output:
Green light on = relay on
Green light off = relay off
Temporary Manual Override
In normal operation it should not be necessary to 
interact with the BDR91T. However it is possible 
to press the button and temporarily override the 
current relay position. This will be cancelled as soon 
as the Relay Box receives another signal from the 
ST9420C, because automatic operation has a higher 
priority than manual operation.
Loss of Wireless Communications
If the RF communication is lost for a period of 1 hour the red light will illuminate.
The Relay Box will then enter the failsafe mode as selected by your Installer (see 
page 34).
When RF communication is restored, the Relay Box will automatically return to 
normal operation.
OPERATING YOUR BDR91T RELAY BOX (IF INSTALLED)
Green LED
Red LED
Push button
Green light, relay status indicator
Push button
Red light, indicator for special modes 
or loss of communications 
						

							27
How do I set the time only, if the ST9420C clock is not correct?
Your ST9420C 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 to confirm the time is correct.  If you have made a change, the message 
‘TIME SAVED’ will show, followed quickly by ‘DATE + TIME COMPLETE’.
c.  Move the slider to the RUN  position, to complete changing the time.
What do I do when the clocks go back in October and forward 
in March?
Your ST9420C is factory set to change the clock automatically at the correct dates, 
so you should never need to adjust the clock forward or backwards yourself. It is 
possible to disable this particular feature, as described in the section ‘Changing the 
Installer Parameters’ (page 15). You may also check the section ‘Configuration 
& Service Data’ (page 34) to see how your Installer has configured your product.
What should I do if I get ‘lost’ while programming the ST9420C?
The LoT™ Display on ST9420C will provide you with help and tips to work through 
the programming. Should you ever get ‘lost’, the simplest thing to do is\
 to move the 
slider to the RUN position, and then move it back to the appropriate programming 
position where you got lost. At this point just follow the instructions again.
What happens if there is a power failure?
In the event of a mains power failure, the ST9420C display will go blank, the 
indicator lamps will go out, and the control outputs will switch off. The real time 
will be constantly maintained by means of the built-in battery backup, ready to 
power back up as if nothing had happened when the mains power is restored. In 
addition, all programmes and settings are stored in a special memory (called Non 
Volatile  memory) which requires no power to maintain information so will be retained 
indefinitely.
Should the correct time and date ever be lost, for whatever reason, the message ‘SET 
DATE + TIME’ will be displayed whilst the slider is in the RUN  position. In this case, 
simply follow the procedure described under ‘Step 1: Setting the Date & Time’ 
(page 6). It should not be necessary to make any changes to your programmes.
FAQ  AND TROUBLESHOOTING 
						

							28
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 message is repeated again.
What do I do if RF communication is lost?
Follow the steps in the Troubleshooting Guide on the next page. The most likely 
cause for loss of communications is the DT92E batteries running low on p\
ower. This 
will be indicated on the DT92E display by a flashing battery symbol, or the display 
may even be blank. Simply replace the batteries (as shown on page 21) and wait a 
few minutes for communications to become re-established.
If this does not resolve the problem it may be that the RF signal path between 
the ST9420C and the DT92E is blocked by a metal object. Check the direct path 
between the two devices and reposition any object that may be blocking the signal, 
or move the thermostat.
How do I know when to change the batteries in the CS92A 
cylinder sensor?
If the CS92A batteries need changing, the ST9420C will show the message \
“SENSOR 
LOW BATT” and the tap symbol  will flash. You can confirm this by pressing the 
CS92A button, whereupon the red light will give a brief flash every second to indicate 
a low battery state. It is important to change the CS92A batteries as soon as the low 
battery condition is indicated, as reduced battery power may affect the RF signal 
strength and impair RF communications.
How do I know when to change the batteries in the DT92E 
room thermostat?
If the DT92E batteries need changing, the battery symbol will flash on the DT92E 
display. DT92E will continue to operate for at least 4 weeks after the indicato\
r begins 
to flash. The ST9420C will also show the message ‘SENSOR LOW BATT’ and the 
radiator symbol 
 will flash. It is important to change the DT92E batteries as soon 
as the low battery condition is indicated, as reduced battery power may affect the 
RF signal strength and impair RF communications.
FAQ  AND TROUBLESHOOTING 
						

							29
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
ST9420C has a blank LCD 
display No power to the 
heating system.Check that there is power to the 
heating system.
Fault in ST9420C
Call Installer
ST9420C indicates that 
Heating and/or Hot Water 
are ON, but radiators are 
cold and/or taps are running 
with cold water.
Temperature controls 
are switched off or 
set too low.Check that the temperature 
controls in the system are set to 
appropriate levels.
Boiler or other 
system controls 
have malfunctioned. Call Installer
ST9420C shows the 
message: 
‘INTERNAL FAULT’ Fault in ST9420C
Call Installer
Every few seconds, the 
ST9420C screen shows the 
message:  ST9420C is 
counting down the 
number of days 
until your next boiler 
service is due.Arrange a boiler service before 
the counter reaches zero.
After servicing your boiler, the 
Service Engineer / Installer will 
reset the ST9420C to remind 
you when the next boiler service 
is due. Each service is normally 
a maximum of 1 year apart.
Although the heating is still 
operating, the ST9420C 
screen keeps flashing the 
message:Your boiler service 
is overdue.
Arrange an immediate boiler 
service.
After servicing your boiler, the 
Service Engineer / Installer will 
reset the ST9420C to remind 
you when the next boiler service 
is due. Each service is normally 
a maximum of 1 year apart.
Can I override the Programmer from the DT92E thermostat?
As well as changing the set temperature from the DT92E, it is also possible to override 
the heating system on or off from the DT92E.  This is only possible if the ST9420C is in 
AUTO or ONCE Modes. If ST9420C is in CONT mode it will not be possible t\
o switch 
the heating off from the DT92E. Similarly, if ST9420C is in OFF mode, it will not be 
possible to switch the heating on from the DT92E. If these latter overrides are required 
it is first necessary to change the ST9420C mode setting to AUTO or ONCE.
FAQ  AND TROUBLESHOOTING 
						

							30
SymptomPossible CauseRemedy
The ST9420C screen shows 
the message: Your boiler service 
is overdue and 
the boiler has 
been automatically 
switched off to 
ensure your safety.Arrange an immediate boiler 
service.
If set to do so, it may be 
possible to obtain limited use 
of the boiler by pressing any 
EXTRA HOUR button. Each 
button press will allow operation 
of the boiler for 1 hour at a time, 
and the screen will display the 
message ‘On 1h’.
After servicing your boiler, the 
Service Engineer / Installer will 
reset the ST9420C to remind 
you when the next boiler service 
is due. Each service is normally 
a maximum of 1 year apart.
ST9420C shows the 
message ‘SENSOR LOW 
BATT’ and a flashing radiator 
symbol 
Your DT92E 
batteries are 
running low on 
power. Change the DT92E batteries 
(see page 21 for how to do 
this).
DT92E shows a flashing 
battery symbol 
DT92E display is blank
ST9420C shows the 
message ‘SENSOR LOW 
BATT’ and a flashing tap 
symbol 
Your CS92A 
batteries are 
running low on 
power. Change the CS92A batteries. 
This is located next to your hot 
water storage tank (see page 
25 for a description of how to 
change the batteries).
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).
FAQ  AND TROUBLESHOOTING