Honeywell ST6400S User Manual

USER GUIDE

TO BE LEFT

WITH USER

ST6400S Full Programmer

42009084-008 R1

INTRODUCTION

The ST6400S programmer controls your central
heating system. It will enable you to select the
times when heating and hot water are switched

ON and OFF.

FEATURES

• 24 hour heating programme.

• Separate 24 hour hot water programme.

• Two ON/OFF switching times per day.

• Built-in programme with typical ON/OFF

times for heating and hot water.

• Override buttons for heating and hot water.

• Extra hour buttons for heating and hot water.

• Built-in battery to prevent loss of programme

and time during power cuts.

• 12 hour am/pm or 24 hour clock format.

INSTALLER SET FEATURES

• Boiler Service Reminder.

• Automatic Summer/Winter 1 hour time

change, from BST to GMT.

The ST6400S and other Honeywell controls in your
central heating system will provide comfortable
temperatures in your home when you want them.

12 HOUR AM/PM or 24 HOUR CLOCK DISPLAY

Your programmer can operate on 12 hour am/pm or
24 hour clock formats. To change the format, ensure
the SETTING SLIDER is in the RUN PROGRAMME
position then press the + and - buttons together for
about 5 seconds. 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.

AUTOMATIC SUMMER/WINTER TIME CHANGE

If your programmer has been set to do so, it will
automatically change the clock from GMT to BST
overnight on the last Sunday of March and back
again in October. In March the clock will ‘spring’
forward by 1 hour, and in October it will ‘fall’ back
by 1 hour.

OPERATING YOUR PROGRAMMER

with Boiler Service Reminder / Shut-down Feature

For normal operation the SETTING SLIDER must be
in the RUN PROGRAMME position.
A red INDICATOR LAMP shows when the heating or
hot water is switched ON.
Two sliders are provided to select how the heating
and hot water are controlled.

The HEATING SLIDER has four positions:
OFF - The Heating will remain OFF.
AUTO - The heating will be switched ON and

OFF automatically according to the heating
programme.

ONCE - The heating will come ON at the rst

programmed ON time and go OFF at the last
programmed OFF time.

CONT. - The heating will remain ON

continuously.

The HOT WATER SLIDER operates in the same
manner as described above for the HEATING

SLIDER.

OVERRIDE

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.

EXTRA HOUR

The EXTRA HOUR buttons switch the heating or hot
water ON for up to 3 extra hours without altering the
programme. Pressing either button once will give
one extra hour, and the words HEATING +1 HR or
HOT WATER +1 HR show on the display to conrm
the button has been pressed.
When the red indicator lamp is OFF, pressing the
EXTRA HOUR button switches the heating or hot
water ON for just one hour.
When the red indicator lamp is ON, pressing the
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
display will change to show the number of extra
hours, for example HEATING +3 HR or HOT WATER
+2 HR.
To cancel the extra hours, keep pressing the EXTRA

HOUR button until the HEATING + (1,2 or 3) HR or
HOT WATER + (1,2 or 3) HR disappears from the

display.

POWER FAILURE

Your programmer has a built-in battery to ensure
correct operation after a mains supply power cut.
No action should be necessary following a power
cut of up to 4 days. Longer power cuts may require
you to re-programme.

BOILER SERVICE REMINDER

By Law, your gas boiler should be inspected once a
year to ensure it is operating safely. If the Programmer
has been set to do so, it will display a message on
the screen to remind you that a Boiler Service is due.
If the Service is overdue, the programmer may switch
off the heating system, to ensure your safety. If this
happens you must arrange an immediate Service
visit. Contact details should be listed below.

If your programmer screen
ashes this message every
few seconds, your Boiler
Service is due soon, and
you should arrange a service visit.

If your programmer screen
shows the words “SERVICE
DUE” then your boiler
service is OVERDUE and
you should arrange an immediate service visit.

If your programmer screen
shows the words “SERVICE
DUE” and “OFF” then your
boiler service is OVERDUE
and the boiler has been switched off to ensure your
safety - you should arrange an immediate service visit.

If set to do so, it may be
possible to obtain limited
use of the boiler by pressing
the heating 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”, as shown above. However, you
should arrange an immediate service visit.

BOILER SERVICE CONTACT NUMBERS

Name Telephone

Contact 1

Contact 2

FAULT INDICATION

If your programmer screen

shows this message, the
product has detected an
internal fault, and must be
replaced, so you should arrange an immediate
service visit.

SERVICE DUE

SERVICE DUE

AM

SERVICE DUE

DAYS

SERVICE DUE

SETTING YOUR PROGRAMMER

SETTING THE CORRECT TIME

To set the correct time, open the ap on the front of
the programmer.

STEP 1

Move the SETTING
SLIDER to the SET
TIME position. The time

on the display will now
be ashing to indicate
it can be changed.

STEP 2

To change the time, press the + or - buttons until the
correct time is displayed.
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 rst,
then quickly.

STEP 3

Moving the SETTING SLIDER to the next position
completes setting the time.

SETTING THE HOT WATER PROGRAMME

The hot water programme has two 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, if required.

STEP 4

Move the SETTING SLIDER to the SET HOT
WATER position. The words HOT WATER will now

be visible on the display and the rst ON time will
now be ashing.

STEP 5

Use the + and - buttons to set the rst ON time.
Each press of the button will change the time by
10 minutes.

STEP 6

Press the NEXT ON/OFF button once to display
the rst OFF time. Set this time using the + and

-

buttons.

STEP 7

By pressing the NEXT ON/OFF and + or - buttons
the remaining ON/OFF times can be set.

*NOTE*

1.

When pressing the + button, the next ON or OFF
marker may start to ash. If this happens the next
programme time will have been changed. Press
the NEXT ON/OFF button to check and adjust this
programme time if necessary.

2. When pressing the - button, the previous ON or
OFF marker may start to ash. If this happens
the previous programme time will have been
changed. Follow the procedure in “REVIEWING
PROGRAMME TIMES” to check and adjust this
time if necessary.

Moving the SETTING SLIDER to the next position
completes setting the hot water programme.

3.00am

4.00am

5.00am

6.00am

7.00am

8.00am

9.00am

10.00am

11.00am

12.00am

1.00pm

2.00pm

3.00pm

4.00pm

5.00pm

6.00pm

7.00pm

8.00pm

9.00pm

10.00pm

11.00pm

12.00pm

1.00am

2.00am

3.00am

HOT WATER
HEATING

BUILT-IN PROGRAMME

3.00am

4.00am

5.00am

6.00am

7.00am

8.00am

9.00am

10.00am

11.00am

12.00am

1.00pm

2.00pm

3.00pm

4.00pm

5.00pm

6.00pm

7.00pm

8.00pm

9.00pm

10.00pm

11.00pm

12.00pm

1.00am

2.00am

3.00am

HOT WATER
HEATING

PERSONAL PROGRAMME

AM

IF DISPLAY REMAINS BLANK AFTER SWITCH ON – SWITCH OFF FOR A FEW SECONDS

AND THEN SWITCH BACK ON AGAIN

AM

+ AND

-

BUTTONS

LCD
DISPLAY

ON/OFF
MARKER

HOT WATER
INDICATOR
LAMP

OVERRIDE
BUTTONS

HEATING
INDICATOR
LAMP

EXTRA HOUR

BUTTONS

HEATING
SLIDER

SETTING
SLIDER

HOT WATER
SLIDER

NEXT ON/OFF
BUTTON

BOILER SERVICE

REMINDER

SETTING THE HEATING PROGRAMME

The heating programme has two 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 to stay on after midnight if
required.

STEP 8

Move the SETTING SLIDER to the SET HEATING
position. The word HEATING will now be visible on
the display and the rst ON time will be ashing.

STEP 9

The required heating programme can now be set by
following the same procedure as “SETTING THE HOT

WATER PROGRAMME” in steps 5 to 7.

STEP 10

Move the SETTING SLIDER to the next position to
complete setting the programme.

REVIEWING PROGRAMME TIMES

To review your hot water programme move the
SETTING SLIDER to the SET HOT WATER
position.
To review your heating programme move the
SETTING SLIDER to the SET HEATING position.
To review the programme times press the NEXT
ON/OFF button repeatedly. Any of these times can
be adjusted by using the + and - buttons.