Truma Combi D comfort plus User manual

Operating instructions
To be kept in the vehicle.
This document is part of the product.
FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings exactly
could result in serious injury, death or prop-
erty damage.
Do not store or use gasoline or other flam-
mable vapors and liquids in the vicinity of
this or any other appliance.
Installation and service must be performed
by a certified service technician.
Diesel furnace with supplementary
indirect water heating
Certified to UL 307A
Certified to UL 174
Certified to CSA B140.10
Certified to CSA-C22.2 No. 110
R
Truma Combi D comfort plus

2
Table of Contents
Trademark information ........................................................ 2
Intended use .......................................................................... 2
Prohibited use ........................................................................ 2
Mounting arrangement / Accessories ................................ 3
Furnace diagram .................................................................... 4
Consumer Safety Information
SAVE THESE INSTRUCTIONS ............................................. 6
Safety symbols and signal words ...................................... 6
Safety behavior and practices ............................................. 6
Safety features ...................................................................... 8
Operating Instructions
How the CombiDfurnace works ....................................... 9
Selectable modes of operation ................................................. 9
Selectable modes of power input ............................................. 9
Room temperature sensor ................................................. 10
Truma pressure relief/drain valve ..................................... 10
Opening the Truma pressure relief/drain valve ....................... 11
Closing the Truma pressure relief/drain valve ........................ 11
Starting the CombiD furnace ........................................... 11
Inspections before each use .................................................. 11
Filling the water container ...................................................... 12
Switching on the furnace ....................................................... 12
Shutdown ............................................................................. 13
Switching off the furnace ....................................................... 13
Draining the water container .................................................. 13
Winterizing ............................................................................. 14
Optional: Winterizing the RV with a winterizing fluid ............. 14
Winter operation ................................................................. 14
TrumaCombiD comfort plus Technical Data ................ 15
“Combi D” MANUFACTURER’S LIMITED WARRANTY 16
Maintenance and service ................................................... 17
Decalcifying and cleaning the water container ...................... 17
Truma pressure relief/drain valve ........................................... 18
Replacing the 12-volt fuses .................................................... 18
Troubleshooting .................................................................. 19
California Proposition 65 lists chemical sub-
stances known to the state to cause cancer,
birth defects or other reproductive harm. This
product contains such substances, be their ori-
gin from fuel combustion (gas) or components
of the product itself.
Trademark information
Truma CombiD comfort plus referred to as
CombiD below.
Truma CP plus referred to as CP plus below.
Intended use
The CombiD furnace with supplementary indi-
rect water heating may be used only in recre-
ational vehicles (RVs) for heating the room and
the faucet water.
Recreational vehicles (RVs) are designed as
temporary living quarters for recreation, travel
and/or camping. RVs have their own power or
are towed by another vehicle.
The CombiD furnace also feature electrical
heating elements for a supply voltage of 120 V.
Prohibited use
Any use other than the intended use (see above)
is prohibited.
Examples of prohibited use:
• Use in a marine environment
• Use as part of a space heating system
• Use in mobile homes
• Use in food trucks or roadside food vending
vehicles
• Use in construction trailers
For long periods of operation at altitudes of
4900 - 9000 ft. (1500 to 2,750 m), an addi-
tional altitude kit is required.

3
Mounting arrangement / Accessories
This is a typical installation for illustration. The installation in your vehicle may vary.
The illustration is not to scale.
Fig. 1
A Wall outlet vent G Combi D furnace
B Room temperature sensor H Wall cowl with exhaust venting system
and combustion air intake
C CPplus control panel I Insulating sleeve
D Truma water pressure regulator J Opening for circulation air intake
(with mounted grid)
E Non-return valve K Warm air ducts
F Truma pressure relief/drain valve L Warm air end outlet with air throttle
70
F
E
D
G
H
K
LJ
A
C
B
I

4
Furnace diagram
11
14
3
2
5
7
8
4
1
10
9
6
15
16
17/18
12
13
Fig. 2
9
9
5
15
7
6
3
2
4
16
1
10
11
8
Fig. 3

5
1 Combi D furnace
2 Connection for combustion air intake
duct
3 Connection for exhaust venting duct
4 Connection for exhaust duct
5 Connector cover
6 Warm air outlets (upper)
7 Warm air outlets (lower)
8 2-pole, 3-wire 120 volt electrical plug
9 Plastic frame feet
10 Aluminum frame feet
11 Circulated air fan
12 Cold water connection (inlet)
13 Hot water connection (outlet)
14 Diesel connection (inlet)
15 Electronics housing
16 Recessed grips
17 Original type plate
18 Duplicate type plate

6
SAVE THESE INSTRUCTIONS
Safety symbols and signal words
This is the safety alert symbol. This symbol
alerts you to potential hazards that can kill or
hurt you and others.
indicates a hazardous situation
which, if not avoided, will result in death or
serious injury.
indicates a hazardous situation
which, if not avoided, could result in death or
serious injury.
indicates a hazardous situation
which, if not avoided, could result in minor or
moderate injury.
is used to address practices not
related to physical injury.
Other important information or tips
Safety behavior and practices
Ensuring a safe operating environment
• Danger of suffocation! To
ensure dissipation of exhaust gases, operate
the CombiD furnace outdoors only.
– Never use in enclosed spaces or tents or
breathe in the exhaust gases.
– If installing an airtight awning, make
sure that the exhaust system terminates
outdoors.
– If the RV is parked in an enclosed space:
– Deactivate the time switch.
– Switch off the CombiD furnace at the
control panel.
In the event of leaks in the furnace or ex-
haust gas system:
• Switch off the device,
• Open windows and doors,
• Have the entire system checked by a service
technician!
• Keep the area around the CombiD furnace
free from combustible materials, gasoline,
and other flammable vapors or liquids such
as pressurized dispensers or wax candles.
Consumer Safety Information • Keep the area in front of the warm air outlets
(Fig. 1–L) free of combustible or heat-sensi-
tive materials. Do not put any material into
the warm air outlets.
• In order to avoid overheating of the CombiD
furnace, keep the air inlets of the CombiD
furnace (Fig. 2–11), the air openings to
the area in which the CombiD furnace is
installed (Fig. 1–J) and the spacing around
the CombiD furnace free of obstruction.
• To ensure clean combustion, keep the wall
cowl free of obstruction. Do not lean any ob-
jects against the wall cowl (Fig. 1–H).
• CARBON-MONOXIDE
POISONING HAZARD!
Failure to follow instructions could result
in severe personal injury or death due to
carbon-monoxide poisoning, if combustion
products enter the RV.
Check that all openings in the outside wall
around the vent (and air intake) pipe(s) are
sealed to prevent combustion products en-
tering the RV.
Check that furnace vent (and air intake)
terminal(s) are not obstructed in any way
during all seasons.
Know the symptoms of carbon monoxide
poisoning: headache, dizziness, weakness,
nausea, vomiting, sleepiness, and confu-
sion. Carbon monoxide reduces the blood’s
ability to carry oxygen. Low blood oxygen
levels can result in loss of consciousness
and death. See a doctor if you or a member
of your family develops cold or flu-like symp-
toms while camping. Carbon monoxide poi-
soning, which can easily be mistaken for a
cold or flu, is often detected too late.
• Danger of hot surfaces. The
temperature of the exhaust gases can reach
356 °F (180 °C). Do not touch the area
around the wall cowl and do not lean any
objects against the wallcowl or the RV.
Responsibilities of the operator
• The operator is responsible for the water
filled into the CombiD water container and
its quality.
• The operator is responsible for protecting the
CombiD furnace against freezing.

7
• How long before hot water causes skin
damage?
Temperature
°F (°C)
Time before skin becomes
scalded
155 (68) 1 second
148 (64) 2 seconds
140 (60) 5 seconds
133 (56) 15 seconds
127 (52) 1 minute
124 (51) 3 minutes
120 (48) 5 minutes
100 (37) safe bathing temperature
Source: Moritz, A.R. / Herriques, F.C.: Studies of thermal injuries: the
relative importance of time and surface temperature in causation of cu-
taneous burns
A. J. Pathol 1947; 23: 695 - 720
• Children up to 17 years of age as well as
people with physical, sensory, or mental
disabilities and/or people who are inexpe-
rienced or unknowledgeable may use the
CombiD furnace only if they are supervised
or have been instructed in the safe use. They
must also understand the risks associated
with using it. Children must not play with the
CombiD furnace.
• During heater operation, do not allow the
tank level to fall as low as the reserve mark
on the tank indicator.
If the vehicle tank is empty, the opening for
the fuel withdrawal line will be approximately
at the level of the fuel surface. In this state,
especially if fuel sloshes in the tank during
travel, large quantities of air are drawn in.
This leads to an irregular device fuel supply.
In this state, the device burner cannot main-
tain clean combustion (formation of fumes).
• The furnace must not be used during refuel-
ling or in enclosed car parks, in garages or
on ferries.
• To avoid damage, make sure no spray water
enters the CombiD furnace. When cleaning
the RV, do not spray directly into the wall
cowl.
• The appliance is not to be used with air
filters.
• Do not operate this product if it has a dam-
aged cord or plug, if it is not working prop-
erly, or if it has been damaged or dropped.”
• The exhaust gas system must be inspected
by an expert at regular intervals or at least
every 2 years.
• Fuel at low temperatures:
Refineries or filling stations automatically
adapt the fuel to the usual winter tempera-
tures (winter diesel). At temperatures below
32°F (0°C) , difficulties can occur if the ve-
hicle is still filled with summer diesel.
To ensure that all heater fuel lines are filled
with winter diesel or other permissible mix-
tures after filling, the heater must be oper-
ated for at least 15 minutes.
Safe operation
• Use with Ultra-low-sulfur diesel fuel (max.
15 ppm sulfur) according to ASTM D975 and
SOR/2005-305 only. Even small amounts of
other volatile fuels or solvents mixed with
diesel can increase the risk of fire or explo-
sion.
Operation with biodiesel is not permissible.
• During the initial start-up of a brand new
appliance, small quantities of fumes and
a slight odor may occur briefly. When the
appliance is started up after a particularly
long period of non-use, there may be some
smoke and/or smell due to dust or dirt. It is
a good idea to allow the appliance to run at
maximum output for a few minutes and to
ensure that the area is well ventilated.
– For using the CombiD furnace in hot water
mode (140°F (60°C)), let it heat up several
times.
• Hot air can be dangerous, es-
pecially for infants, children, the elderly, or
infirm. It can cause burns:
– Always check the air temperature before
varying the air throttle position (Fig. 1-L).
• Hot water can be dangerous,
especially for infants, children, the elderly, or
infirm. It can cause severe burns:
– Never actuate the pressure relief/drain
valve (Fig. 1-F) as long as the CombiD fur-
nace is under water pressure and/or still
hot.
– Always check the water temperature be-
fore entering a shower or bath.

8
Safety features
The CombiD furnace is equipped with the
following safety devices:
Flame monitoring
If the flame goes out, the fuel supply is
switched off.
Low-voltage shut down
If the voltage drops below 10VDC, the fuel sup-
ply is switched off.
Overcurrent protection
If there is a short circuit in the CombiD furnace
(>20 A), a fuse on the control unit is activated
and the CombiD furnace is switched off.
Monitoring of hot water temperature
A water over temperature switch avoids exces-
sively high water temperatures.
Monitoring of hot air temperature
An air over temperature switch avoids exces-
sively high air temperatures.
Safe handling of malfunctions
• Switch OFF the CombiD furnace if anything
seems to be out of the ordinary.
• Danger of fire or explosion
when attempting to use a flood-damaged
CombiD furnace or if the RV has been in-
volved in an accident! A qualified service
technician must inspect the furnace. In the
case of moisture damage, the qualified ser-
vice technician must replace damaged fuel
intake parts, control system parts and/or
electrical parts, or provide a new furnace.
• Only a qualified service technician may per-
form repairs.
• Have a qualified service technician immedi-
ately remedy any malfunctions.
– Remedy a malfunction yourself only if a
remedy is specified in the troubleshooting
chart in these operating instructions (refer
to “Troubleshooting” on page 19).
• After any misfire, a qualified service techni-
cian must inspect the CombiD furnace and
the exhaust tube.
Safe maintenance and repair
• Only a qualified service technician may clean
and maintain the furnace.
• Any alteration to the CombiD furnace or its
controls can cause unforeseen serious haz-
ards and will void the warranty.
• After a long period of winterizing: Flush all
hot/cold water hoses and the CombiD fur-
nace thoroughly with drinking water before
using it.

9
Read and follow the “ ConsumerSafety In-
formation ” before operating the CombiD
furnace.
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.
Water in the hot water container can become
as hot as 162°F (72°C) during operation. If
there is a malfunction, the water can reach
205°F (96°C).
• Always use potable water to fill the hot
water container. The person operating the
furnace is responsible for the quality of this
water.
• Before using a hot water faucet or using
the shower, allow the hot water to run until
the water temperature no longer increases
and mix with cold water.
• 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.
How the CombiDfurnace
works
The CombiD furnace was developed exclusively
for use in recreational vehicles (RVs).
The CombiD is a furnace with a supplementary,
indirect hot water generator.
The CombiD is powered by Diesel and a 12V
power supply. The electrical heating elements
are powered by a supply voltage of 120 VAC.
Room air is drawn into the furnace by a fan,
heated up and conveyed via flexible ducts to the
RV’s interior.
The CombiD furnace with supplementary water
heating is installed between the RV’s fresh wa-
ter supply line and its hot water system.
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
duct in the duct exhaust venting system: an ex-
haust duct inside, an exhaust venting duct out-
side and a separate combustion air intake duct.
Damage to the CombiD furnace
caused by freezing! The CombiD furnace does
not have a frost-protection function. If the heat-
ing is not used and there is a risk of freezing, all
water must be drained from the water container
( “Winterizing” on page 14).
Selectable modes of operation
The CPplus control panel (Fig.1–C) 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 temperature 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D.
The CombiD furnace never operates in any
mode without a 12VDC power supply.
1. Diesel for Diesel mode
The CombiD furnace runs on Diesel.
2. Electricity for electric mode
The CombiD furnace can be powered by elec-
tricity if the RV is connected to a mains power
supply or a generator.
Operating Instructions

10
Room temperature sensor
A room temperature sensor (Fig.1–B) mea-
sures the temperature inside the RV.
The installation location for the room tempera-
ture sensor depends on the RV and will be cho-
sen by the RV manufacturer.
Truma pressure relief/drain
valve
Risk of scalding injury from hot water
and/or tampering with the pressure relief/
drain valve!
• Never actuate the pressure relief/drain
valve as long as the CombiD furnace is
still hot.
• Do not place a plug or reducing coupling
on the outlet part of the valve. If you use a
discharge line, allow the valve and the line
to drain completely.
– The Truma pressure relief/drain valve pro-
vides both the pressure relief function and
a drain function.
– The pressure relief/drain valve is a safety
component and must not be removed for
any reason other than replacement.
– The pressure relief/drain valve is not ser-
viceable; if defective, it must be replaced.
It must be replaced by a certified service
technician.
– It must only be replaced by the Truma
pressure relief/drain valve rated for
65.25psi (4.5bar) which is CSA certified
and registered.
– Tampering with the pressure relief/drain
valve will void the warranty.
The CombiD furnace with supplementary in-
direct water heating must be installed with the
Truma pressure relief/drain valve (Fig. 5) that
complies with the standard for Relief Valves for
Hot Water Systems, ANSI Z21.22.
Only a 120V sine-wave-generator
may be used to avoid damage to the CombiD.
3. Diesel and electricity (mixed mode)
The CombiD furnace runs simultaneously on
Diesel and electricity.
If the selected operating mode is:
1. Heating mode:
The CombiD runs simultaneously with Diesel
and electricity.
2. Hot water mode:
The CombiD runs in electric mode with a
preselected power output setting of 850 W
(Mix1) or 1700 W (Mix2).
When the RV is disconnected from the power
supply*, the furnace will automatically switch to
Diesel.
* With sufficient supply of 12 V DC and Diesel.