Truma CP plus VarioHeat User manual

Truma CP plus VarioHeat
Operating instructions
To be kept in the vehicle.
This document is part of the product.

2
Table of contents
Consumer Safety Information
Safety Definitions ..................................................................... 3
Safety Behavior and Practices .................................................. 3
Intended use .......................................................................... 3
Important notes ..................................................................... 3
Operating Instructions
Display and Operating Elements ........................................ 4
Description ............................................................................... 4
Rotary push button ................................................................... 4
Back button .............................................................................. 4
Initial start-up ........................................................................... 4
Start-up ..................................................................................... 5
Functions .................................................................................. 5
Select setting level .................................................................... 5
Switch on / off .......................................................................... 5
Change the room temperature ................................................. 5
Select the fan level ................................................................... 6
Change hot water mode .......................................................... 7
Set the time switch ................................................................... 7
Set clock ................................................................................... 9
Service menu ............................................................................ 9
Special displays ...................................................................... 11
Warning / Error ....................................................................... 11
Warning .................................................................................. 11
IR remote control ................................................................ 12
Maintenance ........................................................................ 12
Troubleshooting charts ..................................................... 14
VarioHeat (H) .......................................................................... 14
AquaGo (W) ............................................................................ 14
Aventa eco / comfort .............................................................. 16
California Proposition 65 lists chemical sub-
stances known to the state to cause cancer,
birth defects, death, serious illness or other
reproductive harm. This product may contain
such substances.
4010007
Trademark information
Truma CP plus VarioHeat control panel referred
to as CPplusVarioHeat below.
Truma AquaGo referred to as AquaGo below.
Truma VarioHeat comfort referred to as
VarioHeat below.
Aventa eco and Aventa comfort referred to as
Aventa below.
VarioHeat is a furnace. For technical reasons
they it referred to as “HEATING” in the display
text.
FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings exact-
ly could result in serious injury, death or
property damage.
Do not store or use gasoline or other flamma-
ble vapors and liquids in the vicinity of this or
any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Evacuate all persons from the vehicle.
• Shut off the gas supply at the gas container
or source.
• Do not touch any electrical switch or use
any phone or radio in the vehicle.
• Do not start the vehicle’s engine or electric
generator.
• Contact the nearest gas supplier or certified
service technician for repairs.
• If you cannot reach a gas supplier or certi-
fied service technician, contact the nearest
fire department.
• Do not turn on the gas supply until gas
leaks have been repaired.
Installation and service must be performed by
a certified service technician, service agency,
or the gas supplier.

3
Safety Definitions
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, could result in death or
serious injury.
is used to address practices not re-
lated to physical injury.
Other important information or tips.
Safety Behavior and Practices
• Use the CPplusVarioHeat only when it is
in a technically sound condition.
• Have a specialist immediately remedy any
malfunctions. Remedy the malfunction
yourself only if a remedy is specified in the
troubleshooting chart in these operating
instructions.
• Have a defective CPplusVarioHeat re-
paired only by the manufacturer or its ser-
vice department.
• Any alteration to the appliance or its con-
trols can be dangerous and will void the
warranty.
• Switch OFF the VarioHeat furnace and/or
AquaGo when refueling, pumping gas or
when the recreational vehicle (RV) is in a
parking garage, on a ferry, or in enclosed
spaces (such as a garage, repair shop).
Make absolutely sure that the VarioHeat
furnace and/or AquaGo cannot be switched
on via the time switch. To do this, you have
to switch the CPplusVarioHeat off or inter-
rupt the power supply to the control panel.
Consumer Safety Information Intended use
The CP plus VarioHeat is suitable only for in-
stallation in RVs used for recreation, travel, or
camping.
The CP plus VarioHeat controls and monitors
the following appliances:
• VarioHeat
• AquaGo
• Aventa eco / comfort
Important notes
• If the power supply to the system has been
interrupted, the time / time switch must be
reset.
• If a new or replacement appliance (furnace,
air conditioning system or hot water system)
is connected to the bus system, the proce-
dure described in “Initial start-up” must be
repeated.

4
Operating Instructions
Rotary push button
The rotary push button(8) is used to select and
change setpoints and parameters; it is then
tapped to save the values. Selected menu items
flash.
+
–
Turn clockwise
• The menu is scrolled
through from left to right
• Increase values (+)
Turn counterclockwise
• The menu is scrolled
through from right to left
• Reduce values (-)
Ta p
• Save a selected value
• Select a menu item, go
to the setting level
Press and hold
• Main switching function
– control panel on/off.
Back button
Press the back button(9) to go back to a previ-
ous menu and cancel settings. This means that
the previous values remain unchanged.
Initial start-up
Perform the following steps for initial start-up:
1. Switch on the power supply.
– 12 V DC for the CPplusVarioHeat and fur-
nace, air conditioning system or hot water
system
2. Start searching for the appliances in the
menu item “Service menu” –> “RESET” –>
“PR SET”.
When you have confirmed the selection, the
CPplusVarioHeat is initialized. “INIT ..” appears
on the display while this is in progress. This
stores the devices that have been found in the
control panel.
Display and Operating Elements
hot
eco
2
1
3
8
4
5
6
7
9
Fig. 1
1 Display
2 Status line
3 Menu line (top)
4 Menu line (bottom)
5 Power supply display
120VAC (mains supply)
6 Time switch display
7 Settings/Values (displayed text)
8 Rotary push button
9 Back button
Description
• A rotary push button (8) is used to select
menu items in the menu lines (3 + 4) and to
adjust settings.
• Information is shown on a backlit display(1).
• The back button(9) is used to go back to a
previous menu.

5
Start-up
Start / Stand-by screen
When the CPplusVarioHeat is connected to the
power supply, a start screen is displayed after a
few seconds.
Fig. 2
• The display alternates between the cur-
rent time and the room temperature
that you set.
• Special displays on command via
CI-BUS (refer to “Special displays” on
page11).
• After repairs or upgrades, “initial start-
up” has to be repeated.
Functions
The functions of menu lines (Fig.1–3,4) of
the CPplusVarioHeat can be selected in any
sequence. The operating parameters are shown
in the status line (Fig.1–2) or in the display
(Fig.1–6).
Select setting level
• Tap the rotary push button.
The display shows the setting level. The first
icon flashes.
Fig. 3
Switch on / off
Switch on
• Tap the rotary push button.
Previously set values and operating pa-
rameters are active again when the panel
is switched on.
Switch off
• Press the rotary push button for more than
4seconds.
The switch off process of the
CPplusVarioHeat may take a few minutes
due to internal time lags of the furnace, air
conditioning system or hot water system
(“OFF” is displayed during this time).
Change the room
temperature
• Use the rotary push button (Fig. 1 - 8) to se-
lect the icon in the menu line (Fig.4–3).
• Tap the rotary push button to go to the set-
ting level.
• Use the rotary push button to select the fur-
nace (“HEATER”) or air conditioning system
(“AC”).
• Tap the rotary push button to confirm the
selection.
• Use the rotary push button to select between
“OFF”, “VENT”, “COOL”, “AUTO”.
• Push rotary push button to confirm the
selection.
• Select the desired temperature with the ro-
tary push button.
• Tap the rotary push button to confirm the
value.
2
3
c da b e
Fig. 4
Furnace (“HEATER”)
Adjustable temperature range 40 – 86 °F
(1°Fincrements) or 5 – 30 °C (1°C increments)
a = Furnace on – icon is lit;
the icon flashes until the room
temperature is reached.

6
Air conditioning system (“AC”)
Adjustable temperature range 60 - 88 °F (1 °F
increments) or 16 – 31 °C (1 °C increments)
Air conditioning system can also be oper-
ated with IR remote, see page 12.
Icon Displayed
text
Description
b COOL Air conditioning system
is switched on
c AUTO 1Air conditioning system
is set to automatic
d NIGHT Air conditioning system
is set to silent mode
dVENT Air conditioning system is
in air circulation mode
1Symbol flashes until the desired room temperature is reached.
Quick temperature change possible using
rotary push button (in stand-by screen).
Automatic climate control (“AUTO”)
Adjustable temperature range 64 - 77 °F (1 °F
increments) or 18 - 25 °C (1 °C increments)
Automatic changeover between furnace and air
conditioning system for an approximately con-
stant temperature inside the vehicle.
e = AUTO – Automatic climate control is
activated
Requirements for operation with automatic cli-
mate control:
• The furnace and air conditioning system
must be connected.
• Automatic climate control (ACC) must be
activated in the service menu (see “Service
menu” page 9).
Select the fan level
With a furnace / AC connected
1. Use the rotary push button to select the icon
in the menu line (Fig.5–3).
2. Tap the rotary push button to go to the set-
ting level.
3. Select the desired fan level with the rotary
push button.
4. Tap the rotary push button to confirm the
value.
2
3
f g h i j k
Fig. 5
The temperature range below 41 °F (5°C;
“OFF”) must be selected in order to switch
off the furnace.
Furnace (“HEATER”)
Icon Displayed
text
Description
– OFF Fan is switched off.
(only selectable if no ap-
pliance is in operation).
g ECO Low fan level
h HIGH High fan level
i BOOST Rapid room heating
Available if the difference
between the selected and
actual room temperature
is >10°C
(depends on connected
heating appliance)
When the furnace is switched on (room
temperature set), the fan level selected in
the previous heating process is shown in
the status line(Fig.1–2). The default set-
ting is “AUTO”.

7
Air conditioning system (“AC”)
Air conditioning system can also be oper-
ated with IR remote, see page 12.
Icon Displayed
text
Description
– OFF Fan is switched off
(can be selected only if no
appliance is in operation).
gLOW Low fan level
h MID Medium fan level
i HIGH Highest fan level
j NIGHT Ultra-quiet fan operation
for both the indoor and
outdoor fans
(only available in cooling
mode)
Change hot water mode
1. Use the rotary push button to select the icon
in the menu line (Fig.6–3).
2. Tap the rotary push button to go to the set-
ting level.
3
l m n
eco eco
Fig. 6
If the warning “CLEAN” is displayed, the
AquaGo must be decalcified
(see “2.2 CLEAN” page 10).
3. Select the desired hot water mode with the
rotary push button.
4. Tap the rotary push button to confirm the
selection.
5. Select the desired hot water temperature
with the rotary push button 95-120°F
(35-49 °C).
6. Tap the rotary push button to confirm the
value.
Hot water mode
Icon Displayed
text
Description
– OFF AquaGo is switched off.
l ECO The AquaGo is now running
in energy-saving mode.
m COMFOR The AquaGo is now running
in a mode that provides
rapid availability of hot
water.
n ANTIFR Prevention of freezing using
12 V DC electricity:
Operating mode with
installed electric anti-
freeze kit (available as an
accessory) and appliance
switched on. The tem-
perature in the appliance is
automatically kept above
41°F (5 °C).
During operation, the icon
is flashing.
Set the time switch
Risk of carbon monoxide poisoning.
The enabled time switch switches the furnace
on, even when the recreational vehicle (RV) is
parked. The exhaust gas from the furnace can
cause poisoning in enclosed spaces (e.g. ga-
rages, repair shops).
If you park the RV in an enclosed space:
1. Block the fuel supply (gas) to the furnace.
2. Disable the time switch of the
CPplusVarioHeat (OFF).
3. Switch off the furnace on the
CPplusVarioHeat .
If the time switch is “ON”, the “Disable
time switch (“OFF”)” menu is displayed.
1. Use the rotary push button to select the icon
in the menu line (Fig.1–4).
2. Tap the rotary push button to go to the set-
ting level.

8
Enter start time
Use the rotary push button to set the hours and
then the minutes.
24h mode 12h mode
Fig. 7
= a. m.
= p. m.
Fig. 8
Enter end time
Use the rotary push button to set the hours and
then the minutes.
24h mode 12h mode
Fig. 9
= a. m.
= p. m.
Fig. 10
If the start/end time is earlier than the time
when you entered the settings, the operat-
ing parameters are not active until the next
start/end time is reached. Until then, the
operating parameters set outside the time
switch remain valid.
Set room temperature
1. Depending on the connected appliance, use
the rotary push button to choose between
furnace or AquaGo.
2. Tap the rotary push button to confirm the
selection.
3. Select the desired room temperature with
the rotary push button.
4. Tap the rotary push button to confirm the
value.
Fig. 11
Select fan level
1. Select the desired fan level with the rotary
push button.
2. Tap the rotary push button to confirm the
value.
Fig. 12
Select the hot water temperature
1. Select the desired hot water mode with the
rotary push button.
2. Tap the rotary push button to confirm the
selection.
3. Select the desired hot water temperature
with the rotary push button 95-120°F
(1°Fincrements) or 35-49 °C (1 °C
increments).
4. Tap the rotary push button to confirm the
value.
Enable time switch (“ON”)
1. Enable the time switch (ON) with the rotary
push button
2. Tap the rotary push button to confirm the
value.
2
Fig. 13
The time switch remains enabled, even for
several days, until it is disabled (“OFF”).
If the time switch is programmed and en-
abled, the time switch icon flashes.
Disable time switch (“OFF”)
1. Tap the rotary push button to go to the set-
ting level.
2. Disable the time switch (“OFF”) with the ro-
tary push button
3. Tap the rotary push button to confirm the
value.

9
Fig. 14
Set clock
Display 24h mode Display 12h mode
4
Fig. 15
= a. m.
= p. m.
4
Fig. 16
Use the rotary push button(Fig.1–8) to select
the “Set clock” icon in the menu line(Fig.1-4).
The hour display flashes.
1. Use the rotary push button(Fig.1–8) to set
the hours.
2. Tap the rotary push button again and the
minute display flashes.
3. Use the rotary push button to set the
minutes.
4. Tap the rotary push button to confirm the
value.
Service menu
1. Calibrate room temperature sensor of
the furnace (“OFFSET”)
The room temperature sensor of the connected
furnace can be adjusted individually to suit the
location of the sensor. Settings can be made in
the range from 41°F to 23°F (5 °C to -5 °C) in
1°F (0.5 °C) increments.
Example:
Set room temperature 75 °F;
OFFSET = -1 °F;
Setpoint for furnace = 74 °F
Fig. 17
Default setting: 0°F (0°C).
2. AC SET
(Only available if ACC is set to “ON”)
The sensed room temperature can – during
operation of the automatic climate control – be
perceived differently during cooling than during
heating. “AC SET” is used to set an offset be-
tween cooling and heating. The setting can be
made in increments of 1°F (0.5 °C) within the
range of 0 °F to 10 °F (0°Cto5°C).
Fig. 24
Example:
Set room temperature 74 °F;
AC SET = 2 °F
– Setpoint value for air conditioning
system = 76 °F
Presetting: +2°F (+1°C).
3. ACC
(Only available if the air conditioning system
and furnace are connected)
The automatic climate control function AUTO is
activated or blocked with “ACC”.
ON – The automatic climate control function AUTO is ac-
tivated. Automatic climate control function AUTO
can be selected in the Room temperature menu.
– “AC SET” appears in the Service menu.
OFF – The automatic climate control function AUTO is
blocked.
Fig. 25
Presetting: OFF
The function of the Truma automatic climate
control depends on proper installation.
4. AquaGo
Available only when AquaGo is connected.
4.1 CALCI
Indicates the relative level of calcification of the
AquaGo as a percentage.
With 100 % calcification, the warning
“CLEAN” is displayed in the Hot wa-
ter mode menu (see “Change hot water
mode” page 7) and the AquaGo must
be decalcified.

10
4.2 CLEAN
(Only AquaGo comfort / AquaGo comfort plus.)
Irritation of skin and eyes in
case of contact with decalcification agent
Wear protective gloves, eye protection and face
protection to avoid contact.
The directions in the AquaGo
operating instructions must be followed.
Starts or stops the decalcification process.
The AquaGo operating instructions contain
a complete description of the decalcifica-
tion process (see “Decalcification”).
Start = starting decalcification
Stop = interrupting decalcification
When the decalcification process is inter-
rupted, the AquaGo is automatically rinsed
and can be used only after this.
4.3 HARDN
The appliance must be decalcified
regularly depending on water hardness
and hot water consumption.
Specify the hardness of the water that is used.
Is needed to display the relative calcification of
the AquaGo (see “2.1 CALCI”).
Default = 1
Level Water hardness
(mg/l CaCO)
1 Soft
0 - 60
2 Moderately hard
61 - 120
3 Hard
121 - 180
4 Very hard
> 180
5. °C / °F temperature display
Select temperature display °C (Celsius) or
°F(Fahrenheit).
Fig. 18
Default setting: °C (Celsius).
6. Change backlighting
Change the backlighting of the
CPplusVarioHeat in 10increments.
hot
Fig. 19
7. 12h / 24h Mode
Display in 12h (a. m., p. m.) / 24h mode.
Fig. 20
Default setting: 24h mode
6. Change language
Select the desired language (German, English,
French, Italian).
hot
Fig. 21
Default setting: English
8. Show the version number
Display the version number of the furnace,
AquaGo and CPplusVarioHeat .

11
Example:
H 1.20.01 –> H = appliance;
1.20.01 = Version number
Appliance
P = CPplusVarioHeat,
CP plus VarioHeat
CI-BUS
H = VarioHeat
W = AquaGo
Fig. 22
9. RESET
The reset function resets the CPplusVarioHeat
to the factory settings. All your settings are de-
leted. Newly connected devices are recognized
and recorded in the control panel.
• Switch on the power supply
– 12 V DC for the CPplusVarioHeat and Var-
ioHeat furnace
Reset
1. Select “RESET” with the rotary push
button(Fig.1–8).
2. Tap the rotary push button.
3. “PR SET” is shown in the display.
4. Tap the rotary push button to confirm.
Fig. 23
When you have confirmed the selection, the
CPplusVarioHeat is initialized.
“INIT ..” appears on the display while this is in
progress.
Special displays
External control panel (CI-BUS)
If a command is sent from an external control
panel with CI-BUS, “CI” is displayed.
The CPplusVarioHeat CI-BUS is a separate
variant that is fitted only in the factory.
Display energy type
In heating mode, gas (a) is shown as the energy
type
a
Fig. 24
Warning / Error
Warning
If an operating parameter is outside the tar-
get range, the CP plus VarioHeat immediately
jumps to the “Warning / Error” menu level and
displays the respective
fault code. The cause of the warning can be
determined and remedied with the aid of the
troubleshooting guide (from page 14 and ff).
Return to setting level
• Tap the rotary push button or press the back
button. If the display is in stand-by mode,
tap to activate the background lighting and
tap again to acknowledge the warning.
If possible, the appliance concerned contin-
ues to operate. When the operating param-
eter is within the target range again, this
icon extinguishes again automatically.
Display warning code
1. Select the icon (“Fig. 25”) with the rotary
push button.
2. Tap the rotary push button.
– The code of the current warning is dis-
played. The troubleshooting chart (refer to
“Troubleshooting” on page14 and ff)
can be used to determine the cause of the
warning and remedy the error.
a
Fig. 25

12
IR remote control
Air conditioning systems – shared use of
IRremote control and CPplus VarioHeat
• Even after connecting the CP plus VarioHeat,
the IR remote control is still available to con-
trol the air conditioning system.
The CP plus VarioHeat recognises all settings
(except dehumidification mode) that are
made on the air conditioning system using
the IR remote control. The IRremote control
only transmits the settings that are shown in
its display (no bidirectional communication).
• Only the time switch of the
CP plus VarioHeat may be used to clearly
define the start and end time of a required
period.
Maintenance
The CP plus VarioHeat is maintenance-free.
To clean the front, you can use a non-abrasive
cloth moistened with water (and a neutral soap
solution).
Fig. 26
W = Warning
28 = Error code
H = Appliance
H = VarioHeat
W = AquaGo
Malfunction
In the event of an error, the CP plus VarioHeat
immediately jumps to the “Warning / Error”
menu level and displays the respective fault
code. The cause of the error can be determined
and remedied with the aid of the troubleshoot-
ing guide (from page 37 and ff).
Fig. 27
E =Error
2 =Error code
H =Appliance
H = VarioHeat
W = AquaGo
Cause remedied / return to setting level
• Tap the rotary push button.
– The respective appliance is restarted.
This may take a few minutes due to internal
time lags of connected appliances.
If the cause was not remedied, the mal-
function will occur again and the control
panel will again go to the “Warning / Error”
menu level.
Cause not remedied / return to setting level
• Press the back button.
In this case, the error is not acknowledged
in the CPplusVarioHeat and the warning
icon (Fig. 25) remains. The appliance re-
mains in error status. Other connected ap-
pliances can be operated.
Reading out the error fault code
When the error has been acknowledged, the
fault code can be opened again:
1. Select the warning symbol (Fig. 25) with the
rotary push button.
2. Tap the rotary push button. The current error
fault code is displayed.

13
Technical data
Display
LCD, monochrome, with backlighting
Diagonal 3.3in. (84mm)
Dimensions (L x W x H)
3.62 x 4.06 x 1.58in. (92 x 103 x 40mm)
Operating temperature range
13°F to 140°F (-25°C to +60°C)
Storage temperature range
13°F to 158°F (-25°C to +70°C)
Interface
TIN bus
CI-BUS (only CI-BUS model)
Power supply
8 – 16.5VDC
Power consumption
max. 65mA (100% backlighting)
10mA (stand-by)
Quiescent current
3 mA (Off)
Weight
approx. 0.22lb (approx. 100 g)
Protection class
Class III
Protection type
IP00
Subject to change without notice.

14
Troubleshooting charts
VarioHeat (H)
Error code Potential cause Solution
E 2 H,
E 16 H
Flame not detected:
Gas cylinder empty
Replace gas cylinder
Gas cylinder or quick-acting
valve in the gas supply line
closed
Check the gas infeed and open the valves
Butane concentration in the gas
cylinder too high
Use propane. Butane is not suitable for heating,
especially at temperatures below 50° F (10 °C)
Combustion air infeed or ex-
haust gas outlet closed
Check openings for dirt (slush, ice or leaves)
and remove
W 25 H Excess voltage >16.4V DC Check battery voltage and power sources, such
as battery charger
W 26 H Undervoltage, battery voltage
too low < 10V DC
Charge the battery, replace old battery
W 27 H Warm air outlets blocked
Circulated air intake blocked
EN end outlet closed
Remove blockage
Remove blockage
Open EN end outlet
W 29 H Imminent undervoltage, battery
voltage too low < 10.4V C
Charge battery
W 255 H Furnace has no 12VDC power
supply
Ensure 12V DC power supply
No connection between furnace
and control panel
Connect furnace and control panel
If these measures do not remedy the malfunction or if error codes are displayed that you cannot
find in the troubleshooting chart, contact your dealership, Truma Service 1-855-558-7862 or one of
our authorized Service Partners.
AquaGo (W)
Error code Potential cause Solution
E 1 W Flame not detected There is a flame-detection error at the burner
because the flame was not detected after re-
lease of gas and ignition.
Important: The system indicates this error
only after three attempts at intervals of ap-
proximately 30 seconds.
E 2 W Error at over temperature switch-
es (EOS, BOS)
The exhaust over temperature switch (EOS) or
burner over temperature switch (BOS) is open/
unplugged.
E 3 W Error at exhaust pressure switch
(EPS)
The EPS did not close when the flue fan was
actuated because the fan did not push enough
air through the exhaust channel. A cause
could be, e.g., blocking of the exhaust channel
or a faulty switch.
OR The EPS is closed even though the flue fan
is not running. Cause is a defective EPS or flue
fan.
E 4 W Error at water over temperature
switch (WOS)
The WOS opened at a water temperature of
over 185°F (85°C).

15
Error code Potential cause Solution
E 5 W Flame detected at incorrect time There is an error in flame detection of the
burner because the flame was detected:
before ignition or
before the release of gas or
after the gas was switched off.
E 6 W Error in the safety circuit for gas
valve
There is a heating request but gas cannot be
released.
One of the switches WOS, EOS, BOS, EPS is
open/unplugged.
E 7 W Error of burner MCU internal
RAM
Error detected in the burner MCU’s internal
safety monitoring feature (safety variables are
no longer correct or RAM/STACK was over-
written by mistake).
E 9 W Malfunction of water outlet tem-
perature sensor WOT
Water outlet temperature sensor WOT
has a short circuit or
is open/unplugged.
the temperature of the sensor is colder than
14°F (-10°C).
E 10 W Error in the safety circuit There is a heating request but gas is not re-
leased because a valve-actuation signal was
not activated.
E 11 W Error of MCU watchdog gas
release
There is a heating request but the MCU watch-
dog does not release the gas path.
W 12 W Internal error
W 13 W Short circuit shut-off valve Short circuit detection in the gas valve (shut-
off part) detected a current >1000 mA and
shut off.
W 16 W Malfunction of the MCU Internal error of the control unit.
W 20 W Malfunction of water inlet tem-
perature sensor WIT
Water inlet temperature sensor WIT
has a short circuit or
is open/unplugged or
the temperature of the sensor is colder than
14°F (-10°C).
W 21 W Malfunction of circulation line
temperature sensor WCT
Circulation line temperature sensor WCT
has a short circuit or
is open/unplugged or
the temperature of the sensor is colder than
14°F (-10°C).
E 22 W Malfunction of gas valve, modu-
lation section
Error at gas valve, modulation level, because
the modulator has a short circuit or
is open/unplugged.
W 23 W Voltage is too high The main power supply’s voltage detector
measured a voltage level of >16.4 V.
W 24 W Voltage is too low The main power supply’s voltage detector
measured a voltage level of <10 V.
E 25 W Flue fan current consumption
error
The current detector for the flue fan has mea-
sured a current outside the permitted limits.
W 26 W Circulation pump current con-
sumption error
The current detector at the circulation pump
has measured a current outside the permitted
limits.

16
Error code Potential cause Solution
W 27 W Water circulation pump is run-
ning dry.
The circulation pump does not generate water
flow. The water system may not be filled or not
sufficiently vented.
The circulation pump tries (20 times) to gener-
ate a water flow every 30 s (if successful, the
error is reset).
W 28 W Too low gas pressure. Gas supply (in vehicle) to the appliance
insufficient.
W 29 W Too high heat power required. You are trying to use more hot water than the
appliance can supply.
W 30 W Risk of freezing. Temperature in the appliance below 27 °F (3
°C).
W 31 W Decalcification finished. –
W 32 W Current too low. Current in the antifreeze kit too low (e.g. cable
break).
W 33 W Current too high. Current in the antifreeze kit too high (e.g. short
circuit).
If these measures do not remedy the malfunction or if error codes are displayed that you cannot
find in the troubleshooting chart, contact your dealership, Truma Service 1-855-558-7862 or one of
our authorized Service Partners.
Aventa eco / comfort
Error code Cause Remedy
34,
47
Unstable 120 V power supply in
connection with generator or in-
verter operation
Ensure shore power supply 120 V at the unit
input
If none of the measures in the troubleshooting chart proves successful or fault codes are displayed
that cannot be found in the troubleshooting chart, please contact the Truma Service Center at
1-855-558-7862 or one of our authorized service partners.

17

18

19

Manufacturing
Truma Gerätetechnik
GmbH & Co. KG
Wernher-von-Braun-Straße 12
85640 Putzbrunn
Germany
www.truma.com
Sales
Truma Corp
2800 Harman Drive
Elkhart, IN 46514
USA
Toll Free 1-855-558-7862
Fax [phone]
[email protected]
www.truma.net
39050-00701 · 00 · 11/2021 · ©
In case you encounter any problems,
please contact the Truma Service
Center at 855-558-7862 or one of our
authorized service partners. For details see
www.truma.net.
Please have the model number and serial
number (on type plate of appliance) handy
when you call.