• The warm air outlets (Fig. 1 – H), the wall
outlet vents (Fig. 1 – I) and the openings
for the circulated air intake (Fig. 1 – D and
Fig. 2 – 11) must be free from obstructions
to ensure that the furnace functions properly.
Any obstructions might cause the furnace
to overheat. If this happens, the built-in tem-
perature limiter will interrupt the flow of gas
to the furnace. Once the furnace has cooled,
it will switch on again automatically.
• Access to adequate quantities of
LP gas (fuel inlet pressure 11 – 13 in. wc
(27.4 – 32.4 mbar)) and 12 V power must be
available.
The Combi eco plus and Combi comfort plus
models
• Make sure that the supply voltage's fuse
protection of the campground suffices for
operating the furnace in electric mode. The
furnace needs up to 1,700 W (14.2 A) in op-
erating mode 2. If the supply voltage's fuse
protection is not sufficient, the furnace can
be operated in operating mode 1 with up to
850 W (7.1 A).
Danger of damage to the power
cord due to overheating! If you use an exten-
sion cord on a cable drum to connect the
RV to the campground power system, make
sure the cord is fully extended.
Filling the water container
Damage to the water container!
The water pressure on the inlet side must be
limited to 40.6 psi (2.8 bar), otherwise internal
components of the appliance will be dam aged.
On (city) water connections with a pressure
higher than 40.6 psi (2.8 bar) a pres sure regula-
tor is strongly recommended.
1. Close the pressure relief/drain valve, if open
(refer to "Closing the Truma pressure relief/
drain valve" on page 11).
2. Close open bypass lines, if present.
3. Turn on the fresh water supply or switch on
the water pump.
4. Fill the plumbing system:
– Open all water-release points, e.g. cold and
hot water faucets, showers, toilets.
– Once water flows, the plumbing system is
ventilated and filled. Close all water-release
points.
12
Switching on the furnace
For the furnace to work properly, there must
be enough LP gas (propane >11 in. wc) and
12 VDC power. Optionally, for electric or
mixed mode with the Combi eco plus and
Combi comfort plus, an additional 120 VAC
power supply is needed.
1. Switch on the furnace's 12 VDC power supply.
2. If necessary, fill the water container with wa-
ter (refer to "Filling the water container" on
page 12). If no hot water is needed, the
Combi furnace can be operated without be-
ing filled.
3. Make sure the supply of LP gas is turned on
at the tank.
4. Make sure the gas shut-off valve is switched
on (refer to "Switch for gas shut-off valve"
on page 10).
Operation without gas supply is
possible for the Combi eco plus and
the Combi comfort plus. The maximum
heating power is then 1,700 W.
5. Use the CP plus control panel to switch on
the Combi furnace (refer to the CP plus man-
ual for additional instructions).
Scalding injuries caused by hot water!
Water temperatures over 127 ºF (52 ºC) can
cause severe burns or scalding and in extreme
cases even death.
• Before using a hot water faucet or using
the shower, mix with cold water and allow
the hot water to run until the water tem-
perature no longer increases.
• Test the temperature of the water before
placing a child in the bath or shower.
• Do not leave a child or an infirm person in
the bath unsupervised.