Specifications

DT90 DIGITAL ROOM THERMOSTAT
EN0H 8578 UK07 R1 12/08
7
INSTALLER MODE – HOW TO SET PARAMETERS
Each parameter is identified by a 2-letter code, and has a range of values. These are shown in the table below,
followed by instructions on how to enter Installer Mode, how to select a parameter and change its value, and finally
how to exit Installer Mode.
To enter Installer Mode:
a. Put DT90 into off/standby mode by pressing and
holding the off/standby button for 2 seconds.
b. Now press and hold both ▲ and ▼ temperature
adjustment buttons for 3 seconds, until the
display shows the word “Inst”.
c. Press the ▲ button to get to the first parameter
Ot. The parameter code is shown on the display
separated by a colon from the parameter value.
To select and change a parameter:
d. Use the ▲ and ▼ buttons to move from one
parameter to another.
e. Press the off/standby button to select the
parameter value, ready to change
f. Use the ▲ and ▼ buttons to adjust the
parameter value. When the correct value is
flashing, confirm the selection by pressing the
off/standby button again, returning to the
parameter menu.
To exit Installer Mode:
g. Press and hold the off/standby button for 3
seconds
Note: Installer Mode will exit automatically after 10
minutes if no buttons are pressed.
Description
Parameter
Range of values
Factory (default) value
Minimum ON/OFF time
Ot
1, 2, 3, 4, 5 minutes
1 minute
Cycle rate
Cr
3, 6, 9, 12 cycles/hour
6
Proportional band width
Pb
1.5 to 3.0°C
1.5°C
Temperature measurement offset
tO
-3 to 3°C
0
Upper setpoint limit
uL
21 to 35°C
35°C
Lower setpoint limit
LL
5 to 21°C
5°C
Energy saving ECO temperature
(this parameter is only available on
the DT90E model)
ES
5 to 35°C
18°C
Selection of heat/cool changeover
HC
0 = disable
1 = enable
0
Off/standby setpoint *
OS
-- = off,
5 to 16°C
5°C
Electric heat operation
EH
0 if < 3A
1 if > 3A
0
Reset parameters
FS
0, 1
1 (factory settings)
* In cooling mode the off/standby setpoint defaults to OFF
Parameter
Value