15
The thermostat has user defined settings where
the duration of the legionella Override/Boost can
be adjusted from 1 to 7 days or completely disa-
bled to operate as a conventional dual cylinder
thermostat.
1. To disable/adjust the legionella boost turn
the unit off by pressing and holding down
the HOLIDAY button until an audible click is
heard and the red LED turns off and the digi
-
tal display goes blank.
2. Release the button and after approx. 10 sec-
onds press and hold the HOLIDAY button
again. After 5 seconds an audible click is
heard, the red LED will light up and the digi-
tal display will come back on, keep the HOLI-
DAY button pressed for a further 5 seconds
until the digital display flashes.
3. Release the button and use the HOLIDAY
button to choose between disabling the
override/Boost (OF in display) or setting de-
lay between boost/override from 1 - 7 days
(1-7 in display)
4. Once selected release the button and the
unit will return to the user set position within
5 seconds
4.6 Holiday mode
Holiday mode is set using the black button locat-
ed under the display. Press and hold the holiday
switch (1) for a minimum of 10 seconds until you
hear an audible click, and this switches the digital
Dual Cylinder Thermostat off completely so there
is no water heating and no weekly “boost” heat-
ing. When in Holiday mode, the display is off. This
feature should only be used when the property
is vacant for extended periods and there is no
requirement for water heating or for the weekly
“boost”.
Pressing and holding the holiday switch (1)
again for a minimum of 10 seconds until you
5
4 3
2
1
49°
1
20
30
40
50 60 70
80
90
100
110
10
120
0
°C
5
4 3
2
1
49°
5
4 3
2
1
49°
hear an audible click will restart the Electron-
ic Dual Cylinder Thermostat, the display will
show the cylinder temperature and the weekly
“boost “ will immediately start, and recur every 7 days
at the same time depending on the user set position.
4.7 Lower (solar) coil
Heat sources to unvented hot water cylinders
must be controlled by a thermal cut-out as well as
a thermostat. The OSO Solarcyl is supplied with
solar sensor pockets . The solar controller (not
supplied) and solar sensor point should be wired
through the OSO thermal cut-out.
4.8 Solar control
A Differential Solar Controller is required to achieve
Solar thermal control and Solar water heating.
Please note that the direction of flow in the solar
coil is reversed compared to the boiler coil. If the
cylinder is not being used for solar use, connect
the boiler to the lower coil with the primary flow in
a bottom to top direction.
If using a 6-wire 28mm or 1” BSP V4043H on ei-
ther circuit the white wire is not needed and must
be made electrically safe.
4.8.1 Solar controller pipe fitting and wiring
4.5 Adjusting the 1 hour boost
1
1
2
2
3
1
2
3
L
N E
N L C NC NO
L
N
E
Solar
controller
wiring
Solar
th.stat
Differential
solar controller
Summary of Contents for Delta Twincoil DTC 200
Page 26: ...26 NOTES ...
