Function Description; Fuel Supply; Fuel Quality; Fuel At Low Temperatures - Truma Combi D 4 Operating Instructions Manual

Function description

The Combi D 4 diesel heater is a warm air heater with an
integrated hot water boiler (10 litre volume). The burner is fan-
assisted, which ensures that operation is problem-free, even
when on the move.
In heating and hot water mode the heater can be used to
heat the room and heat water up at the same time. If only hot
water is required, select hot water mode.
– In hot water mode, the water is heated at the lowest
burner setting. Once the water temperature has been
reached, the burner switches off.
– In heating and hot water mode, the unit automatically
selects the required operating level according to the tem-
perature difference between the temperature set on the
control panel and the current room temperature. If the
boiler has been filled, the water is automatically heated as
well. The water temperature depends on the selected oper-
ating mode and the heater output.
At a temperature of approximately 3 °C at the automatic
FrostControl safety/drain valve, the valve will open and
drain the boiler.

Fuel supply

Fuel quality

The heater requires DIN EN 590 diesel fuel for operation. Op-
eration using bio-diesel (PME, RME or AME) is not permitted.

Fuel at low temperatures

The refineries and filling stations will automatically perform
the required adjustments for the usual winter temperatures
(winter diesel).
Difficulties can occur at temperatures below 0 °C if the vehicle
still has summer diesel in its fuel tank.
If no special diesel fuel is available for use in low tempera-
tures, e.g. winter diesel, then petroleum or benzine should
be mixed in with the fuel, in accordance with the instructions
given by the vehicle manufacturer.
Temperature
0 °C to -20 °C Winter diesel
-20 °C to -30 °C. Polar or Arctic diesel
Used oil should not be used as an additive!
To guarantee that all fuel lines of the heater unit are filled with
winter diesel or another permitted mixture after fuelling, the
heater must be operated for at least 15 minutes.

Operating instructions

Read the safety instructions and operating instructions
carefully before starting the unit.
Operating instructions can be viewed in offline mode
with a mobile device and the Truma App. Download the
operating instructions when you have a WiFi connection and
save them on your mobile device.
Before initial use, be sure to flush the entire water supply
thoroughly with clear water.
The materials of the appliance that come into contact
with water are drinking water safe (see manufacturer's
declaration: www.truma.com – Manufacturer's Declaration).

Control panels

The control panels are described in separate operating
instructions.

Room temperature sensor

To measure the room temperature, an external room tempera-
ture sensor (2) is located in the vehicle. The position of the
sensor is determined by the vehicle manufacturer depending
on the vehicle model. More information can be found in the
operating instructions for your vehicle.
Figure 2
The temperature setting on the control panel depends on per-
sonal heating requirements and the design of the vehicle, and
must be determined individually.

FrostControl

(safety/drain valve)
FrostControl is a currentless safety/drain valve. When there
is a danger of frost, it automatically drains the contents of
the boiler through a drainage socket. If excessive pressure is
present in the system, pressure will be automatically intermit-
tently equalized through the pressure relief valve.
c
b
Figure 3
a = rotary switch position "On"
b = pushbutton position "Closed"
c = pushbutton position "Drain"
d = drainage socket (led outside through floor of vehicle)
2
a
d
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