
ThermoPlus AS1
User Operating Instructions
The ThermoPlus AS1 - Programmable Room Thermostat offers
a number of pre-installed heating profiles which are simple to
set-up by the installer or user to provide maximum
comfort. Once complete, user operations are kept to a
minimum by using the +/ - and Warm/Cool buttons on the front
of the unit.
PLEASE NOTE: The ThermoPlus contains a selection of five
pre-set and one adjustable profile options, one of these profiles
should have been set by the Installer to meet your heating
requirements. Care should be taken to ensure the correct
profile is selected that most suits your lifestyle. Details on
how to change the selected profile are located on page 9 of
this guide.

Introduction and operating guide
The ThermoPlus AS1 has been designed to be a simple to use
thermostat, requiring minimal user intervention. The normal day
to day operation is taken care of by the pre-set heating profiles,
any temporary adjustments are simply made by using the + and
– buttons. The indicator lights react to any temporary user
adjustments made, the LED indicators work in the following
way;
Warm is shown by two red lights (6) and Cool is shown by a
single blue light (5). The centre button (3) marked 'Warm/Cool'
allows you to toggle between warm and cool settings.
When one or more red lights are on, you can increase the
temperature by pressing the + button (1). For example, press
once to go up by 1 degree or press twice to go up by 2 degrees.
When the two or three red lights are on, the temperature can
also be lowered by using the – button (2). For example, press
once to go down to the warm setting temperature and press
again to go down to one degree below warm setting
temperature.
The Blue light means the unit is working to the lower
temperature and the + or – buttons do not work when this blue
light is on. To change to the warm setting press the 'Warm/Cool'
button.
Under the flap (7) is a blue button (4). During the summer, or
when you want your central heating off for long periods, for
example if you go on holiday, press the Blue button and close
the flap. When you want to go back to normal operation, open
the flap and press the blue button again, remembering to close
the flap once finished.
Both the Warm and Cool temperature settings can be fully
adjusted, this operation is detailed on the next page.
2

Warm and Cool Temperature Adjustments
The ThermoPlus has two preset temperature levels, these are
known as 'Warm', higher level temperature(21 °C) and 'Cool',
lower or set back temperature(15 °C). The preset temperatures
have been selected to give a comfortable, safe, yet efficient
temperature level in the home.
In certain installations it may be necessary to adjust either
the 'Warm' and / or 'Cool' temperatures to meet the specific
needs of the user. This can be achieved by following the
simple steps below; (Additional information is also contained
within the General Information section of this guide)
6
1
2
3 5 4 8 7
3

Warm and Cool Temperature Adjustments
Thermoplus Programming Mode
The ThermoPlus AS1 has been designed for minimal user
intervention, however should any changes be required please
press buttons 4 and 8 simultaneously to enter the programming
mode, this will allow you to;
- Check the current time/date/year
- Check the current profile
- Set a new pre-set profile
- Set a user defined profile
PLEASE NOTE; Upon completion of
the instructions above, please
ensure that you exit the programming
mode by pressing button 4 and 8 simultaneously.
Time and Date Check
The ThermoPlus thermostat has been pre-set with the current
time and date during manufacture. No alteration should be
required to the time and date, however if any modification
is required please refer to the flowchart on next page.
Open
Cover
Select warm
or cool
temperature
by pressing
“WARM /
COOL”button
Adjust the
temperature
by using + / buttons
Once
adjustment
is complete
close the
cover
4
8
4

Time and Date Check
Open Cover
Enter programming mode
(Details given on the previous page)
Press TIME
Press SET
MINUTE flashes,
adjust using + / -
buttons
Press SET
HOURS flashes,
adjust using + / -
buttons
Press SET
DATE flashes,
adjust using + / -
buttons
Press SET
MONTH flashes,
adjust using + / -
buttons
Press SET
Press SET
YEAR flashes adjust
using + / - buttons
Press EXIT
5
Exit programming
mode

Setting Heating Profiles
The ThermoPlus AS1 contains a selection of five preset and one
user definable profile options, one of these will have been set by
the Installer. Care should be taken to ensure a profile is selected
that suits your lifestyle the best. Profiles one to five are detailed on
pages 7 and 8. If none of the preset profiles meet your
requirements it is possible to set a user defined profile, full details
are given on page 9.
Open Cover
Enter programming mode by pressing
buttons 4 & 8 simultaneously
Press PROG
Press SET
Select the required profile by using the + / - buttons
Press SET
Press EXIT
Exit PROGRAMMING mode
Profiles one to five have fixed programmes, they can be reviewed by
pressing the set button once the selection process detailed above has
been completed. To set a custom profile please refer to the instructions
on page 9.
6

The ThermoPlus has six heating profiles, five are fixed and one is adjustable.‘ONE’
has been set as the default and is detailed below. During installation a heating
profile should have been set to best match your requirements; illustrations of the
preset below shown are profiles.
Heating Profiles
24 HOUR
ONE – DEFAULT
START STATUS
EVERY DAY 06:00 WARM
22:00 COOL
PROFILE TWO START STATUS
EVERY DAY 06:00 WARM
08:00 COOL
17:00 WARM
22:30 COOL
PROFILE THREE START STATUS
EVERY DAY 06:00 WARM
08:00 COOL
11:30 WARM
13:30 COOL
17:00 WARM
22:30 COOL
1
PROFILE
24 HOUR
2
PROFILE
24 HOUR
3
PROFILE
1
1
TIME
TIME
TIME
PROFILE
PROFILE
PROFILE
WARM
WARM
WARM
COOL
COOL
COOL
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
7
7
7
8
8
8
9
9
9
10
10
10
11
11
11
12
12
12
13
13
13
14
14
14
15
15
15
16
16
16
17
17
17
18
18
18
19
19
19
20
20
20
21
21
21
22
22
22
23
23
23
00
00
00
TIME PROFILE
TIME PROFILE
TIME PROFILE
TEMPERATURE PROFILE
TEMPERATURE PROFILE
TEMPERATURE PROFILE
Profiles One To Three
24 Hour - Same Profile Each Day
7
1

Profiles one to five have fixed periods, no alteration to the Warm / Cool
times can be made, if it is necessary to make any alterations then
profile six must be used. Profile six will allow you to set up a profile to
your exact requirements. Please refer to the flowchart on page 9.
Profiles Four and Five
5 Day/ 2 Day - Different Weekday / Weekend Profile
START STATUS START STATUS
MON - FRI 06:00 WARM SAT/SUN 07:00 WARM
08:00 COOL 22:00 COOL
11:30 WARM
13:30 COOL
17:00 WARM
22:30 COOL
PROFILE FIVE START STATUS START STATUS
MON - FRI 06:00 WARM SAT/SUN 07:00 WARM
08:00 COOL 22:00 COOL
17:00 WARM
22:30 COOL
4
PROFILE
5/2 DAY
5
PROFILE
5/2 DAY
1
TIME
TIME
MON - FRI
MON - FRI
SAT/SUN
SAT/SUN
WARM
WARM
WARM
WARM
COOL
COOL
COOL
COOL
2
233445566778899101011111212131314141515161617171818191920202121222223230000
TIME PROFILE
TIME PROFILE
TEMPERATURE PROFILE
TEMPERATURE PROFILE
MON - FRI
MON - FRI
SAT/SUN
SAT/SUN
1
8

6
PROFILE
User Definable - 7 Day Programming
Profile Six
Open Cover
Enter programming mode
(Details on page 4)
Press PROG
Press SET
Adjust the warm start time by
using the + / - buttons
and confirming with the SET
button
Adjust the cool start time by
using the + / - buttons
and confirming with the SET
button
Once a day has been
completed press either; SET -
continue to next day COPY -
apply altered setting to the
next day Or exit
Press EXIT
Exit Programming mode
Repeat until
each required
period is set
Repeat until
each required
period is set
COPY FEATURE
The copy feature can be used to
apply changes made from one
days programming to the next.
This is achieved by pressing the
down arrow button when 'SET'
is displayed on the screen.
'SET' is displayed after the last
cool period is confirmed on each
day.
9

Warm and Cool Temperature Adjustment
The Warm and Cool target
temperature settings on the
ThermoPlus AS1 are fully
adjustable. To change a
target temperature it is first
necessary to press the the
centre button to bring up the
'Warm' or 'Cool' setting
(Indicated by the red or blue
LED indicators). By using the
up/down keys under the flap
the 'Warm/Cool' temperature
c a n b e i n c r e a s e d o r
decreased to the desired
temperature setting
PLEASE NOTE - it is not possible to set the warm setting to
below that of the cool setting or vice versa.
Once a new temperature has been set on either the Warm or
Cool setting the AS1 will continue to use this setting until the
next manual adjustment.
PLEASE NOTE - The AS1 will display any temporary
change the user has made by pressing the + or - buttons, this
does not indicate a permanent change in either the Warm or
Cool settings, the temperature will return to the pre-set levels
at the next switching period. During an override the 'Warm'
or 'Cool' setting will not be displayed on the LCD.
Press here to select Warm or Cool
10

To increase
Press
To decrease
Press
Warm and Cool Temperature Adjustment
11

Resetting the ThermoPlus AS1
Electronic equipment can in some circumstances be affected by electrical
interference. If the display becomes frozen or scrambled; or if you wish to
revert back to the default settings please use the following procedure.
To reset press
Reset Procedure
PLEASE NOTE; Using this procedure will restore the ThermoPlus to
the original factory programme settings, the time setting will also
default to 1st January 2005.
RESETTING THE THERMOPLUS AS1
On the ThermoPlus AS1 press the 'UP' and 'DOWN'
arrow buttons together:
Then release the buttons and the thermostat will return to preset
factory settings.
12

General Information
Frost Protection
The Blue button situated under the flap will initiate the frost
protection mode when pressed, the word 'STANDBY' will
appear on the display, the thermostat has been preprogrammed with a frost protection temperature level of 7°C,
this can be adjusted by using the up and down arrow buttons.
Battery
The programmer is fitted with a non-rechargeable, long life
battery, which will maintain the programmed time settings for a
minimum of 12 months with the supply disconnected. THIS
SH OU L D B E SU FF I CI E NT TO CO VE R PO W ER
INTERRUPTIONS DURING THE LIFE OF THE UNIT. During
power interruptions the LCD display and LED indicators will not
function.
Service and Repair
The ThermoPlus AS1 is NOT user serviceable. Please do not
dismantle the unit. In the unlikely event of a fault developing
please refer to the RESETTING THE THERMOSTAT section of
this user guide located on page 12. If this fails to resolve the
problem please contact a local heating engineer or a qualified
electrician.
13

Part Number P82312 Issue 2
South Bristol Business Park,
Roman Farm Road, Bristol BS4 1UP
t: +44 117 978 8700
e: sales@horstmann.co.uk
www.horstmann.co.uk