Summer Mode; Winter Mode (Heating Without Hot Water Production); Winter Mode (Heating With Hot Water Production); Advanced Functions - Webasto Dual Top ST 6 Workshop Manual

The Dual Top ST modulates the temperature steplessly and pre-
cisely for a consistent temperature.
The boiler can be drained simply and directly via the control
panel.
Two different frost protection functions protect the Dual Top ST
and the vehicle against frost during winter holidays.
The heater detects the difference between the set temperature
and the inside temperature and automatically adjusts the re-
quired heating capacity.
The programmable control panel enables you to select from a
large number of modes for your convenience (see chapter 4,
"Operating Instructions" in the document "Operating Instruc-
tions").
Depending on which function you want, hot water in summer
mode, just heat, or heat and hot water in winter mode, sev-
eral options are available.
4.1

Summer mode

The heater provides hot water. The water is heated up to, and
kept at 40 °C or 70 °C / 104 °F or 158 °F.
The heat is produced by a diesel powered burner (Dual Top ST 6
and 8) or an electric heater (Dual Top ST 8). If the combustion
burner is selected as the heat source, the device automatically
selects the burner setting. Water can also be heated by electri-
city, 230 V, from an external power supply (Dual Top ST 8).
Dual Top ST 8: low-power = 1,000 W*
A water temperature sensor controls the water temperature.
Due to variable operating and environmental influences, small
water temperature deviations are possible.
The hot air fan for heating the interior is not activated.
* The high-power option with 2,000 W cannot be used in sum-
mer mode (Dual Top ST 8).
4.2 Winter mode (heating without hot
water production)
In this mode the heater provides hot air.
Heat is produced by a diesel powered burner (Dual Top ST 6
and 8), an electric heater, or a combination of both (Dual Top
ST 8).
For Dual Top ST with a manual control panel:
The desired interior temperature can be adjusted with the in-
terior temperature selector (5 to 35 °C).
For Dual Top ST with a programmable control panel:
To adjust the desired interior temperature, push button (1)
or (2) (5 to 35 °C).
If the combustion burner is selected as heat source, then the
device automatically selects the burner setting, modulating
between 1,500 W and 6,000 W, depending on the output re-
quirement (calculated from difference between selected temper-
ature and current interior temperature).
The amount of heat is regulated to reach the preselected in-
terior temperature quickly. After which only a limited amount of
power is needed to maintain the interior temperature.
If electricity is used as source of energy, the electric heater heats
the air and water at low or high power, depending on the selec-
tion. Electricity is taken from an external power supply. (Dual
Top ST 8).
If the burner and the electric heater provide the heat, priority is
given to the electric heater. This means that the electric heater
runs at low or high power (depending on the selection) and the
burner provides the rest of the heat if necessary. (Dual Top ST
8).
9019782C WSH Dual Top ST
You can heat the interior with or without water in the
boiler.
4.3 Winter mode (heating with hot
water production)
In this mode the heater heats the interior and produces hot wa-
ter.
Heat is produced by a diesel powered burner (Dual Top ST 6
and 8), an electric heater, or a combination of both (Dual Top
ST 8).
For Dual Top ST heaters with a manual control panel:
The desired interior temperature can be adjusted with the in-
terior temperature selector (5 to 35 ºC).
For Dual Top ST heaters with a programmable control panel:
To adjust the desired interior temperature, push button (1)
or (2) (5 to 35 °C).
If the combustion burner is selected as heat source, then the
device automatically selects the burner setting, modulating
between 1,500 W and 6,000 W (Dual Top ST 6) or 1,500 W and
8,000 W (Dual Top ST 8), depending on the output requirement
(calculated from difference between selected temperature and
current interior temperature).
The amount of heat is regulated to reach the pre-selected in-
terior temperature quickly. After which only a limited amount of
power is needed to maintain the interior temperature.
A water temperature sensor controls the water temperature,
while an interior temperature sensor controls the interior tem-
perature.
Due to variable operating and environmental influences, small
water temperature deviations are possible.
Only for Dual Top ST 8: If you use electricity as source of en-
ergy, the electric heater heats the air and water at low or high
power, depending on the selection. Electricity is taken from an
external power supply.
If the burner and the electric heater provide the heat, priority is
given to the electric heater. This means that the electric heater
runs at low or high power (depending on the selection) and the
burner provides the rest of the heat if necessary.
4.4

Advanced functions

n Menu driven user guidance in six languages.
n Programmable timer: The device has two freely program-
mable heating programs, 24/7.
See Programming timer in the Operating Instructions.
n Remote control by Webasto Telestart (optional control).
See Remote control in the Operating Instructions.
n Boiler drainage: possibility to drain the boiler manually from
the control panel or automatically for frost protection.
See Frost in the Operating Instructions.
n Frost protection mode: protects the boiler against frost.
See Frost protection in the Operating Instructions.
n Textual fault information: when a fault occurs, the control
panel displays a fault message with a fault number and
brief description to inform the user about the kind of fault.
See Fault Message output in the Operating Instructions.
5

Troubleshooting

Many faults are caused by improper installation. Always check if
the cause of a fault is improper installation, or if this cause can
be excluded. See chapter , "Table 401: Faults due to improper
installation" on page 8.
Troubleshooting | 5
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