Selectable Modes Of Operation; Selectable Modes Of Power Input; Switch For Gas Shut-Off Valve - Truma Combi eco Operating Instructions Manual

Room air is drawn into the furnace by a fan,
heated up and conveyed via flexible ducts to the
RV's interior.
The Combi furnace with supplementary water
heating is installed between the RV's fresh wa-
ter supply line and its hot water system.
The water pressure on the inlet side must be
limited to 40.6 psi (2.8 bar). If necessary, install
a Truma water pressure regulator (Fig. 1 – K).
A comfortable water temperature at the shower
head is reached by mixing in cold water.
A wall cowl allows combustion air to flow into
the furnace and exhaust gas to flow out. The
wall cowl and the furnace are connected by a
tube in the tube exhaust venting system: an ex-
haust tube inside and a combustion air intake
tube outside.
Damage to the Combi furnace caused
by freezing! The Combi furnace does not have
a frost-protection function. If the heating is not
used and there is a risk of freezing, all water
must be drained from the water container (refer
to "Draining the water container" on page 13).

Selectable modes of operation

The CP plus control panel (Fig. 1 – B) is used to
switch between modes of operation (refer to the
CP plus manual for additional instructions).
1. Heating mode
The furnace automatically selects the proper
operating level based on the difference between
the desired temperature set at the control panel
and the current room temperature. If there is
any water in the water container, it will be heat-
ed automatically. The water temperature will
not be regulated, but it will reach a maximum of
162 °F (72 °C).
2. Hot water mode
(only if water container contains water)
Hot water mode is ideal if only hot water is re-
quired. The lowest burner setting suffices for
heating water. In hot water mode, the burner will
switch off as soon as the water reaches the tem-
perature selected in the CP plus control panel.
Both modes of operation can be combined.

Selectable modes of power input

The CP plus control panel is used to select vari-
ous modes of energy for the Combi eco plus
and Combi comfort plus models.
No Combi furnace operates in any mode with-
out a 12 VDC power supply.
1. LP gas for gas mode
All Combi furnaces run on LP gas (propane).
2. Electricity for electric mode
The Combi eco plus and Combi comfort plus
furnaces can be powered by electricity if the
RV is connected to a mains power supply or a
generator.
Only a 120 V sine-wave-generator
may be used to avoid damage to the Combi.
3. LP gas and electricity (mixed mode)
The Combi eco plus and Combi comfort plus
furnaces run simultaneously on LP gas (pro-
pane) and electricity. Mixed mode is available
in heating mode only.

Switch for gas shut-off valve

The switch (Fig. 4) shuts off the power to the
safety gas shut-off valve and with this the gas
supply to the Combi furnace. To make sure that
the gas supply to the furnace is off, turn the
switch to the OFF position.
Gas shut-off valve
Fig. 4
Switch positions of the switch for gas shut-off
valve:
Off = gas shut-off valve is closed
On = gas shut-off valve is open
Switch
for gas shut-off valve
9