Honeywell ST9400C User manual

i p>'
'.
[ .. ·
i~
r·
' ..
r ·-··
...

I •
·ST9400C Controls Layout
•
-
an4ooc
ON1 @!) ON3
OFF1 OFF2 OFF3
Honeywell
+
OK
HOT WATER
HEATING
RUN
.\ ..
0 Hot Water Operating Mode Indicator
f) Time Display
• ·Heating Operating Mode Button
0 OK/Next Button
G) ·Clock ~ and +Buttons
I
f) LoT™ Technology Display
8 Programme Time Markers
I eDay of Week Indicator
4D Hot Water OPerating Mode. Button
G) Holiday Button
GHeating Operating Mode lndi~ator
8 Heating Extra Hour Button
8 Heating Indicator lamp
f) Heating Override Button
G) Slider
~ Copy Day Button
f; Next Da~ Button
G) Hot Water Override Button
G). Hot Water Indicator lamp
~ Hot Water Extra Hour Button
Keep this document in a Home Information Pack

,.
.. ,
Contents
WHAT IS A PROGRAMMER?
General Description........................................................................................3
The way to use a Programmer........................................................................3
GETTING STARTED WITH YOUR ST9400C
Step 1: Setting the Date & Time ......................................;............................. .4
Step 2: Running a Built-in Programme ...........................................................5
PROGRAMMING YOUR ST9400C
The Built-in Programmes ................................................................................6
.
Your Personal Programme ..............................................................................6
Reviewing the Programme Times ...................................................................7
Modifying
the Hot Water Programme .............................................................7
Copying
one day's Programme to another day .....................................8
Programming a Different
Day .................................................................8
Exiting HOT WATER Programming Mode ..............................................9
Modifying
the Heating Programme.................................................................9
Exiting HEATING Programming Mode ...................................................9
Disabling/Enabling
Time Periods ...................................................................9
OPERATING YOUR ST9400C
Choosing
the Operating Mode ....................... ~ ............................................. 10
·Override the Operation Without Changing the Programmes........................ 10
·The Extra Hour Function ............................................................................... 11
The Holiday Function.................................................................................... 1.1
FINE TUNING YOUR ST9400C
Changing
From AM/PM Time display to the 24-hour Clock ......................... 12
.. Changing the Installer Parameters .............................................;................. 12
FAQ &TROUBLESHOOTING
How do I set the time only, if the ST9400C clock is not correct?......... ~; ....... 14
What do I do when the clocks go back In October and forward in March? .14
What should I do if I get 'lost' while programming the ST9400C? ................ 14
-what happens if there is a power failure? .................................................... 14 ·
Troubleshooting Guide .................................................................................
15 .
0 MINI-PROGRAM.MER OPERATING INSTRUCTIONS
(Installer to tick Ifconfigured In thla way)
What is a Mini-Programmer?.........................................................................16
Modifying the Heating & Hot Water Programme .......................................... 16
Exiting HEATING & HOT WATER Programming Mode ................................. 16
Disabling/Enabling Time Periods ................................................................. 17
Choosing the Operating Mode..................................................................... 17
Override and Extra Hour Functions.......................................................:.: .. :.17
Other Functions ............................................................................................
17
CONFIGURATION &SERVICE DATA
Configuration Data (to be completed by Installer) ....................................... 18
Boiler & System Service Log ........................................................................ 19 f)

General Description
Your Honeywell ST9400C provides timing control for both your central heating and
hot water systems, letting you set ON and OFF periods to suit your own lifestyle.
. . .
The ST9400C does not directly control the temperature butworks togetherwith other
temper~ture controls, such as room thermostats and cylinder thermostats, to control
your heating and hot water system
in your home.
With 7-day programming and up to 3 on/off periods per day,
ev-ery day can be set
differen.tly, and heating and hot·water can be set at different times from each other.
The following instructions explain how to programme and use the ST9400C to
provide the most home comfort at the least cost.
The way to use a Programmer
Think about the time periods when you are typically in the house and when you are
not, and also the times when you use a lot of hot water. These are
~he times you
should use as the basis for the programmes. It will be necessary
to altow some
heat-up time for the heating system after periods when it has been off -this would
typically be 1 - 1
Y2 hours, depending on your house and your preferences.
Other features are commonly available on the Programmerto enhance comfort and
convenience, for example, OVERRIDE, EXTRA HOUR, and MODE buttons.
A typical use ofthe OVERRIDE feature is whenyou return home unexpectedlyforthe
rest of,the day and the
heating is off. Just press the heating OVERRIDE button and
the heating will come on until the next programme time, at which point it will follow
the normal programme. The advantage here
·is that you do not have toremember to
switch off because the normal time programme does this for you.
•
A typical use of the EXTRA HOUR·button would be if you returned to the house for
a short period when the heating and hot water were off. Pressing the appropriate
EXTRA HOUR button gives you
1, 2, or 3 hours of heating, exactly when you need
it. Another typical use is when the heating is already on and you want it to stay on a
little
longer- just press EXTRA HOUR and, for that day only, an hour will be added
to the end of the time at which heating normally goes off.
The MODE buttons allow you to select how you want to operate heating and hot
water independently. The most obvious use is to switch heating OFF during the
summer months, but you may also use this feature if you take a mid-week day off
work, you can then set the MODE to ONCE to keep the system ON during the day
from the first programmed ON time till the last programmed OFF time.

Your ST9400C should have been set up to work correctly when it was installed.
However, thefollowing will
show you howyou can modifyyoursettings to meet
your p_articular lifestyle. ·
To assist you with programming and everyday use your ST9400C will. display text
messages ateverystage to help you
get the most out ofyour central heating and hot ·
water system. The ST9400C uses
LoTTM Technologyto constantly updatethe display
to give you feedback about what is required. ·
Step 1: Setting the Date & Time
Your ST9400C had the date and time set at the factory, and these are normally
maintained
by a backup battery in the event of power failures. If you wish to change
the date or time, or if the
LoTTM Display shows the message 'SET DATE +TIME' just
follow the instructions below. Otherwise,
go to Step 2.
a. Move the slider to the DAY/TIME position. The message 'SET DATE + TIME' will
show briefly on the screen, followed
by 'SET THE DAY', and the day of the month
will now
be flashing to indicate it can be changed.
HOT WATER HEATING
DAY !TIME
SET THE :·]R':J
HOT WATER
' /
?,/
HEATING
.,- - J .......
/ '
RUN
"""""'
.........
eBB)
Honeywell
(~)
,.
b. To change the day of the month, press thee:> • or • buttons until the correct
day is shown. Each press of the button will change the date by one day. As soon
as a change has been made, the message 'IS DAY OK?' will
be displayed. Once
the correct
day is reached, press the greene button to confirm, and move to .
the next step. If you
do not need to make a change, just press the f) button
immediately and this will move you to the next step.
c. The month digitswill
now be flashing and 'SET THE MONTH' will be displayed. To
change the month, press the €) • or• buttons until the correct month is shown.
The message 'IS MONTH OK?' will be displayed. Press the green
f) button to
confirm the month is correct, and move to the next step. .·

GETTING STARTED WJ"'"H ~OUR ST9400C
d. The year digits will now be flashing and 'SET THE YEAR' will be displayed. To
chang.e the. year, press the€) • or• buttons until the correctyear is shown. The
message
'IS YEAR. OK?' will be displayed. Press the greene button to confirm
the year
Is correct. If you have made a change, and the date is a valid date, the
·message 'DATE SAVED' will show,
and you can move to the next step. Ifthe date
you set'was not valid, for examp·le
31 September, the rnessage 'INVALID' will
show and you will be returned
to the start of the date setting operation.
e. The time will now be flashing and the message 'SET THE TIME' will be displayed.
To change the time, press the e) tJ or. buttons until the.correct time is shown.
Each press of the button will change the time
by one minute. Holding the button
down for more than a few seconds will change the time slowly
at first, then
quickly. The message 'ISTIME OK?'will be displayed. Press the green
Obutton
to confirm the time is correct. If you have made a change, ,the message 'TIME
SAVED' will
Show, followed quickly by 'DATE+ TIME COMPLETE'.
t Move the slider to the RUN position, to compiete setting the date and time.
Note: if the slider is moved at any time before the date and time have been set
correctly, the message 'DATE UNCHANGED' will be displayed briefly, and your
changes will not be saved.
·Step 2: Running a·Built·in Programme·
With the date and time correct, your ST9400C Programmer will\now be operating
to the built-in programmes. These have been designed to provide heating and hot
water at typical times throughout the day, but if you want to customise the settings,
please see the next section 'PROGRAMMING
YOUR ST9400C' (page 6).

The Built-in Programmes
The built-in programmes give you a starting point that you can personalise to your own
requirements. Your Installer should have selected one and ticked the box alongside it. If there
is no tick, the product normally leaves the factory with Profile A installed, but it is a simple
matter to select one of the other profiles (see Changing the Installer Parameters, page 12).
D Built-in Programme (Profile A)
DBuilt•in Programme (Profile b)
DBuilt-in Programme (Profile C)
ON 1 OFF 1
Your Personal Programme
The table below has been left blank for you to record your own personal programme.
ON 1 OFF 1 ON 2 OFF2 ON 3 OFF3
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday

~ PROGRAMMING \'OUR S"f9400C
Reviewing the ProgrammeTimes
To review your hot water programme, move the slider to the HOT WAT-ER position.
To review.your heating programme, move the slider to the HEATING position.
To review the programme times, press the t) button repeatedly. The appropriate
ON and OFF markers will be displayed to show you which time is being reviewed.
Any of these times can be adjusted by using the
E!) • or 8 buttons, and then
confirmed using the
t) button. Remember to -return the slider to the RUN position
after reviewing
is complete.
Modifying the HotWater Programme
The hot water programme has three pairs of ON/OFF switching times per day. Each
time can
be set between 3.00 am and 2.50 am (on the next day) to allow you to
programme the hot water to stay on past midnight, ifrequired.
a. Move the sliderto the HOT WATER position. 'SET HOT WATER' will show briefly
to verify this action.
DAYifiME
HOT WATER
HEATING
RUN.
--
HOT WATER
HEATING
--
C~) Honeywell C~)
b. 'SET ON-TIME 1' will then be displayed and the time setting for the first ON 1
time for MONDAY will now be flashing to indicate it can be changed. If you do
not wish to change the time, press the green e button and move to the next
step. If you do wish to make a change, use the
E!) • or • buttons to change
the first
ON 1 time. Each press of the button will change the time by 10 minutes.
As soon as the time has been changed, the message 'ON-TIME 1 OK?' will be
displayed. Press the green 8 button to confirm the time is
correct and move to
the next step.
'SAVED' will be displayed for a moment to confirm that any change
has been saved to memory.
HOT WATER HEATING
HOT WATER HEATING
~MON.:.
MON
.
SET O~J- TimE
O~J- TiffiE
I OV?
" .
'\. / '\. /
..... , ..... ,-,;;
,fJ•Jf.t .....
JoN1 i: ON2 ON3
; OFF1' OFF2 OFF3
:5='10~
{§Ei) ONJ ON3
OFF1 OFF2 OFF3
--- -
c 100m) Honeywell c talE) c MODE) Honeywell c ~)

I I
'
Note: When pressing the • button the next ON or OFF marker may start to flash.
This indicates you have tried to set a time equal to one of the next programme times
already
in the memory. Similarly, when pressing the e button the previous ON or.
OFF marker may start to flash. This indicates you have·tried to set a time eqUal to
one of the previous programme times. If this happens the ST9400C simply moves
both times together as long as you continue to press the
@8 or• buttons. Follow
the procedure
in 'Reviewing the Programme Times' (page 7) to check and adjust
these times as necessary.
c. 'SET OFF-TIME 1' will be displayed and the first OFF 1 time will now be flashing. If
you do not wish to change the time, press the green ebutton and move to the next
step. Otherwise,
use the €) • or • buttons to change the time. Press the green .
button to confirm the time
is correct and move to the next step. 'SAVED' will be
displayed for a moment to confirm that any change
has been saved to memory.
d. The remaining ON and OFF times (ON 2, OFF 2, ON 3, OFF 3} can be set by
using the €) • or 8 buttons to change the time, and the green 48 button to
confirm the time
is correct and move to the next step. If you do not wish to
change the time, just press the green button to move directly to the next
ON/OFF time without making any changes. -
e. After setting or reviewing the last off time,
OFF 3, the message 'COMPLETE' will
be displayed to indicate the times for Monday have been set.
You now have a choice of how to set the programme for the next day:
Copying one day's Programme to another day (example Monday to Tuesday):
f. Whilst the day is showing Monday, Press the COPY DAY button. The message
'COPY MON
TO TUESDAY OK?' will be displayed and the letters TUE will flash
to indicate the programme for Monday can be copied to Tuesday.
g. To select a different day to copy to, press the NEXT DAY button to cycle through
the days. With each press of the
NEXT DAY button the message will change to
indicate the new day you are copying to.
h. When the required day is indicated, press the green ft button to confirm, arid
the message 'MON COPIED' will be displayed for a moment. The day into which
Mondays programme has been copied is now available to have its programme
edited.
Note: Once a day's programme has been confirmed in this way, it now becomes the
day whose programme
is copied if the COPY DAY button is pressed again.
OR
Programming a Different Day:
i. Press the NEXT DAY button to select the next day, which is displayed along the
:i top of the screen. The programme for that day can then be adjusted by following
~ steps b - e above. Programmes for the remaining days can be set in the same
~ way, using the NEXT DAY button to move to the next day.
,,
( :'

> " PROGRAMMING Y'OUR SJ79400C
Exiting HOTWATER Programming Mode:
To exit HOT WATER programming mode, move the slider to the RUN position. This
can be
done at any time during the programming process, and any changes made
and confirmedwith
thee button will have been saved.
Note: If the unit is left in HOT WATER Programming mode for more than 10 minutes without
· the slider being moved or any buttons pressed, the message 'MOVE SLIDER' will be
displayed. Press a button to finish programming, or move the slider to the RUN position.
Modifying the Heating Programme
The heating programme" has three pairs of ON/OFF switching times per day. Each
time can
be set between 3.00 am and 2.50 am (on the next day) to al1ow you to
programme the heating to stay on past midnight, if required.
a: Move the slide switch to the HEATING position. 'SET HEATING' will show briefly
to verify this action.
b. Now follow the same procedure to set the times as described in 'Modifying the
Hot Water Programme' (page 7) steps b. to i.
Exiting HEATING Programming Mode:
To exit HEATING programming mode, move the slider to the RUN position.This can
be done at any time during the programming process, and any changes made and
confirmed with thee button will have been saved.
Note: If the unit is left in HEATING Programming mode for more than 10 minutes without
the slider being moved or any buttons pressed, the message 'MOVE SLIDER' will be
disp1ayed. Press a button to finish programming, or move the slider to the RUN position.
Disabling I Enabling Time Periods (for Heating and/or HotWater)
To disable any of the time periods ON 1 to OFF 1, ON 2 to OFF 2, or ON 3 to OFF 3,
simply setthe ON time and its paired OFF time to the same time, and the programme
will just ignore them.
Tore-enable the time period, simply set the two
ON and OFF times to be different.
(9)

BAERAIING ~DUB SI9400G · : . · · .... : · .. :., · "
~ ~~ ~>~~> ~X
Choosing the Operating Mode (for Heating and/or HotWater)
The operating mode may only be changed when the slider is set
to the
RUN position.
A green INDICATOR LAMP shows when the heating or hot
water
is switched ON.
Two MODE buttons are provided to select the Operating Mode
and therefore how the heating and hot water are controlled.
DAY/TIME ·
HOT WATER
HEATING
RUN
. Heating has four possible Operating Modes; these are OFF, AUTO, ·ONCE, CONT.
Pressing the heating MODE button scrolls round these modes
in· sequence, and the
display indicates which mode
is currently active.
HOT WATER
HEATING HOT WATER HEATING·
SAT SAT
19-06-2010 . 19-06-20 I0
I,-,_,, ll AM
,,-, .,-, ll AM
CONT
,,_,.,_, ,
CONT
,,_,.,_, , CONT.
ONCE . ONCE
. CONCE~
OUTO~
OUTO~
AUTO .
OFF OFF OFF
---
(~)
Honeywell
(~)
Honeywell
(111@00) .
• OFF mode
The heating will remain OFF.
• AUTO
(Automatic) mode
The heating will be switched ON and OFF according to the heating programme.
•
ONCEmode
The heating will come ON at the first programmed ON time, and go OFF at the
last programmed OFF time.
• CONT
(Continuous) mode
The heating will remain ON continuously.
The hot water MODE button operates
in the same way as described above for the
heating MODE button.
Overriding the OperationWithout Changing the Programmes
In AUTO and ONCE operating modes, the OVERRIDE buttons switch the heating or
hot water ON or OFF without altering the programme.
When the indicator lamp
is ON, pressing the OVERRIDE button switches the heating
or hot water OFF until the next programmed ON time. ·
When the indicator lamp is OFF, pressing the OVERRIDE button switches the
heating or hot water ON until the next programmed OFF time.
The
LoT™ Display will provide you with information about the override.
~

OPERATING 'YOUR ST9400C,.
The Extra Hour Function (forHeating and/or HotWafer)
The EXTRA HOUR buttons allow you to switch the heating or hot water ON for up to
3 extra hours without altering the programme. Pressing
e~ther button once will give
I
one extra hour. The Lo T™ Display will display the message '+ 1 HOUR', to confirm
the button has been pressed.
When the green INDICATOR
LAMP is OFF, pressing an EXTRA HOUR button
switches the heating or hot water ON for just one hour.
When the green INDICATOR
LAMP is ON, pressing an EXTRA HOUR button
extends the programmed ON period by one hour. ·
Further presses of the EXTRA HOUR buttons will increase the extra hour period
by
one hour for each button press, up to a maximum of 3 hours. The LoT™ Display will
continue toprovide information on the extra hour status.
To cancel the extra hours, just keep pr~ssing the EXTRA HOUR button until the
'CANCELLED' message appears on
the· Lo TTM Display.
The Holiday Function
TheHolidayfunction allowsyou to switch offyour heating and hotwaterfor a specified
number of days (from 1-99 days). This lets you save energy and related costs when
you are awayfrom home, but resumes normal operation on the day of your return.
To set the Holiday function:
a. Ensure the slider is in the RUN positton, then pr.ess the HOLIDAY button once.
The message 'SET HOLIDAY' will appear briefly, fol1owed by 'SET
DAYS AWAY'.
b. Use the
E9 • or8 buttons to set the number of days you will be away. The display
will show the number of days, and this number will be flashing to indicate it can be
changed. The day of the week will also keep changing to show the day you return.
c. If you have made a change to the number of days, the message
'DAYS AWAY OK?'
will appear. Press the green tD button to confirm your selection.
d.
The message 'SAVED' will be displayed for a few seconds, followed by the date you
return, to enable you to check you have programmed the holiday function correctly.
e. During the holiday period, the
LoTTM Display will show the message 'ON
HOLIDAY' and the display will count down the number of days till you return.
To cancel the Holiday function:
f. To cancel the Holiday function, just press the HOLIDAY button again. The LoT™
Display will show 'CANCELLED' and the unit will return to normal operation.
Note: while setting the Holiday function, if there is a gap of more than 1 minute
between button presses, the function will cancel·itself automatically and return to
normal operation.

/·-....
Changing from AM/PM Time Display to the 24 Hour Clock
Your ST9400C can operate on the 12 hour AM/PM or 24 hour clock formats.· To
change the format, ensure the slider is in the RUN position then press and hold the
e:>• and8 buttons together for about 2 seconds. Ignore the 'NOT VALID' message
that will appear briefly. All the displayed times will be automatically changed to the
new format.
Repeating this procedure will change'the clock display back to the original format.
Changing the Installer Parameters
The ST9400C has a special Installer Mode where some features can be adjusted
tosuityour 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.
INS"'I"AillEB.·. ··Parameter .. ~ Default l1Rtia.~s-· ~· ilescriptioJ1 . :.:~ :· ·. ·. ·
P~R~~~!EB ... "... . Number __ . -~~~~·~.e .... ·~-- .f.:: .. :~J· ·. . ..... : ...... ;;_ .......... " .
24hr or am/pm 1 12
12,24
12 = am/pm display,
clock display. 24 = 24hr display
Configure backlight 2 2
0, 1,2
0 =off
< '
operation. 1 =
on if button pressed,
1 2
=on continuously ·
I
Enable/disable auto 3 1
0, 1 0 = disabled,
time change. 1
=enabled
1-day or 5/2-day or 4 7
1, 5, 7 1 = 1-day operation,
7-day.operation. 5 = 5/2-day operation,
7 = 7-day operation
Number of ON/OFFs 5 3
2,3
2 =·2 on/offs per day,
per
day.
3 = 3 on/offs per day
Select default time 6 A
A,b,C A = standard,
programme. b
=at home,
C =economy
Configure 7 0 0,1
0 =standard Programmer,
Mini-Programmer. 1 = Mini-Programmer
This will be set by
your Installer
and
will depend on your
system -do NOT
change without
contacting installer.
Reset all parameters 8 1
0, 1 0 = do not reset
-1
=default parameters
C\

, , FINE il.JNING YOUR ST94DOC
To Enter Installer Mode: .
a. Ensure the slider is in the RUN position, then press and hold f) and e buttons
· togetherfor 8 seconds. Ignore the 'NOT VALID' message that is displayed for a
few seconds. The message
'SET UP MENU' will show briefly, followed by 'SET
.. INSTALLER OK ?' .
b. Press the4» button to take you into the Installer Mode Parameter Menu.
c. Parameter 1 is now available to change. This is to allow you to change the
clock format from 12 hour AM/PM to 24
hour. At every step, the LoTTM Display
will inform you what the parameter means
and what option you have selected.
The parameter number is shown
on the display separated by a coion from the
parameter va1ue.
d. You· canchange the parameter value by pressing the e) • ore buttons. At this
point the description
in the LoTTM Display will change and the parameter value
will flash. If you press
f) the value will stop flashing and be saved for use. ,
e. Press 8 to move to the next parameter available for editing.
. f. Keep pressing to step·around the list of parameters, and use e) • or •
buttons to change the parameter value.
g. Any parameter changes that have been confirmed with the ft button will be
saved and used. ·
To Exit Installer Mode:
h. You can exit Installer Mode at any time by moving the slider to the next position
· and then back again to
RUN.
Note: Installer Mode will exit automatically after 10 minutes if the slider is not
moved.

nAQ J\ND :TRGt.JBl..ESHOOTING " ",' ·
How do I set the time only, if the ST9400C clock is not
correct? .
Your ST9400C contains a very accurate digital clock that is factory pre-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 e button until the message" 'SET THE TIME' is
displayed.
To change the time, press the e) • or • buttons until the correct
time
is shown. The message 'IS TIME OK?' will be displayed. Press the greenf)
button to confirm the time is correct. Ifyou 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 theclocks go back in October and forward
in March? · ·
Your ST9400C is factory-set to adjust 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 thisparticularfeature, as described
in the section 'Changing the
Installer Parameters' (page 12).
You may also check the section 'Configuration &
Service Data' (page 18) to see how your Installer has configured your product.
What should I do if I get 'lost' while programming the
ST9400C?
The LoTTM Display on ST9400C 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.
Whathappens if there Is a power failure?
In the event of a mains power failure, the ST9400C 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 NV memory)
which requires no power to maintain Information, and so will be retained indefinitely.
Should the correcttime 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 4). It should not be necessary to make any changes to your programmes.

, , FAQ AND 'TROUBLiESHOOTING
Troubleshooting Guide
This is a quick guide to help you diagnose and cope with possible problems with
ST9400C. For further assistance, please contact your Installer.
l"-"' '~ ~' y vH' ) ~~-;;. .,._. ) A )A ~ ~ "< •v Y"YY ~A '.'~~-.,;w~,_,. > v; y> ' V v 'Y•f >v 'A)'7;<o"p ?.,f"">'->'1:-> >- m..-.' '0' .,._.
-Symptom Possible Cause Remedy
' >,
A AAY ~ >)A .-.'~ ~y A '<vYA 'V) A .>~>v,AAYY."•M~>/.# h •- A Au,;..,., • "'''"'"' AW'>> -~~' '"'""""'"""''"'"'""''" YAA' ~ '-~'Y
ST9400C has a blank ·
LCD display
ST9400C indicates
that Heating and/or
Hot Water are ON, but
No power to the
heating system
Fault
in ST9400C
Temperature controls
are switched off or set
too low
Check that there is power to the
heating system
Call Installer
Check that the temperature controls
in the system are set to appropriate
levels
radiators are cold
and/ J------------f---------------1
or taps are running
with cold water.
ST9400C _shows the
message 'INTERNAL
FAULT'
When the slider is
moved to the HOT
WATER position, the
display shows 'NOT
VALID'
Boiler or other
system controls have
malfunctioned
Fault in ST9400C
ST9400C has been
configured as a
Mini-Programmer
Call Installer
Call Installer
Check the Contents page of this
booklet or the 'Configuration &
Service Data' section (page 18)
to see if your ST9400C has been
configur-ed as a Mini-Programmer.
Call
lnstal~er to check ifthis is
correct for your heating system.

j
'!
I
I
You need only refer to this section if:
• The Mini-Programmer
box is ticked on the Contents page of this booklet, or ·
• The ST9400C Configuration Data (page 18) indicates it is set as a Mini-
.Programmer.
What is a Mini-Programmer?
In a poorly controlled gravity circulation hot water system, whenever the b.oiler
comes on to service the heating, there will inevitably
be some circulation though the
hot water storage tank, which will then heat up.
So, whenever the HEATING is ON, the HOTWATER is also ON.
It is therefore NOT possible to have independent programmes for heating
and hot
water, so it is only necessary to enter one time programme.
Ifyou have this
type of installation (gravitycirculation hotwatercircuitWITHOUTa hot
water control valve), your Installer should have restricted the ST9400C Programmer
to
be a Mini-Programmer.
This section describes how
to use the product as a Mini-Programmer.
Modifying the Heating & HotWater Programme
The heating & hot water programme has three pairs of ON/OFF switching times per
day. Each time can
be set between 3.00 am and 2.50 am (on the next day) to allow
you to programme the heating &hot water to stay on past midnight, if required.
a. Move the slider to the HEATING position. 'SET HEATING' will show briefly to
verify this action.
b. Now follow the same procedure to set the times as described
in 'Modifying the
Hot Water Programme' (page 7) steps b to I.
Exiting Heating & HotWater Programming Mode:
To exit HEATING Programming mode, move the slider to the RUN position. This can
be done at any time during the programming process,
and any changes made and
confirmed with the 8 button will have been saved.
Note: If the unit is left in HEATING Programming mode for more than 10 minutes
withoutthe slider being moved
or any buttons pressed, the message 'MOVESLIDER'
will be displayed. Press a button to finish programming, or move the slider to the
RUN position.

. MINI-PROGRAMMER OI?ERATING INSIRUCI/IONS
Disabling I Enabling Time Pe.riods
I
To disable any of the time periods ON 1 to OFF1, ON 2 to OFF 2, or ON 3 to OFF 3,
simply set the ON time and its paired OFF time to the same time, and the programme )
will just ignore them.
To re-enable the time period, simply set the two ON ~:md OFF times to be differeqt.
Choosing the Operating Mode
In a Mini-Programmer, some Operating Modes are not possible. ror example,
HEATING in AUTO mode and HQT WATER in OFF mode is not allowed. When
configured, your ST9400C knows which combinations of Operating ·Mode are
possible, and only permits those combinations that are allowed.
Override and .Extra Hour Functions
When you use the hot water OVERRIDE or EXTRA HOUR functions, they will
operate as normal. However, the heating OVERRIDE
or EXTRA HOUR functions will
also bring
on the .hot water. This is a consequence of the type of system you have,
and is perfectly normal.
Other Functions
All other f\-!nctions operate the in t.he same way as for the standard ST9400C.