VELIT 4000P User manual

4Kw/14000BTU Gasoline/Diesel
Air Heater User Manual
VER 1.0

4Kw Air Fuel Heaters
Thank you for purchasing this VELIT 4000P Gasoline/Diesel air heater.
For safety and best performance, please read and follow the instructions
carefully. The electronic version of this document is available under the
product page at velitcamping.com.
WARNING Improper installation or repair of Velit 4000P air heater can
cause fire or leakage of deadly carbon monoxide leading to serious
injury or death. To install and repair Velit heating and cooling systems,
you need to strictly follow this user manual and use only genuine Velit
parts. ALWAYS carefully follow Velit installation and repair instructions
and heed all WARNINGS. Velit rejects any liability for problems and
damage caused by improper installation or service.
WARNING
1. The heater shall not be used in areas with flammable and
explosive gas and dust.
2. The heater is prohibited to be used in the garage and other
enclosed spaces to prevent suffocation or exhaust poisoning.
3. When installing heaters on special vehicles, relevant specific
rules shall be followed, and it is strictly prohibited to install heaters in
violation of industry rules.
4. Explosive and flammable materials such as gas tank, compress
air tank, clothing, wood, plastic, etc. are strictly prohibited near the hot
air outlet and the exhaust outlet.

4Kw Air Fuel Heaters
Table of Contents
I. Overview························································································· 1
II. Structure and Components···························································· 2
III. Installation···················································································· 4
IV. Operation···················································································· 14
V. Electrical Diagram········································································ 18
VI. Error Codes and Troubleshooting··············································· 19
VII. Care and Maintenance······························································· 20

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I. Overview
1.1 Product introduction
Velit 4000P air heater is consisted of a drive unit (combustion air fan,
heating air fan and drive motor), heat exchanger, burner with
combustion chamber, control unit, glow plug and housing. The ignition
and fuel supply are automatically controlled by the control unit. After
starting up, fuel will be pumped into the combustion chamber and
ignited by the glow plug. Meanwhile the heating air fan pulls the indoor
cold air into the heat exchange channel. The air will be heated up by the
heat exchanger and then pushed into the cabin area.
1.2Technical Specifications
Heat output (Btu/h)
14000
Fuel
gasoline
diesel
Rated Voltage (V)
12
Operating voltage (V)
11-16
Fuel consumption (G/ h)
0.05~0.13
0.05~0.12
Rated power (W)
20~46
Working temperature
-30°F - 75°F
Rated elevation (ft)
≤17000
Weight (Lb)
10
Dimensions (inch)
14.6*5.5*5.9
1.3
2
3

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II. Structure and Components
2.1 Heater components
1. Heater fan 2. Motor 3 Support frame 4. Fuel line rubber plug 5. Motor mount 6.
Control unit 7. Control unit mounting screw 8. Compressor wheel 9. Screw 10.
Screw 11. Burner 12. Fuel inlet 13. Fuel line gasket 14. Glow plug 15. Combustion
chamber flange seat 16. Combustion chamber 17. Screw 18. Motor sealing gasket
19. Screw 20. Combustion chamber sealing gasket 21. Heat exchanger 22. Heat
exchanger rubber ring 23. Glow plug cap 24. Temperature sensor.

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2.2 Housing components
1.Inlet cap 2. Upper housing 3. Lower housing 4. Outlet cap

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III. Installation
3.1 Accessory diagram
3.2 Installation
3.2.1.1 The heater can be installed inside or outside the vehicle. When
the heater is installed outside the vehicle, it must be ensured
that the installation location will not be exposed to rain and
debris on the road.
3.2.1.2 Appropriate spacing must be reserved at the installation
location of the heater, as shown in the following to ensure
proper air flow. The inlet and outlet must be free of obstruction.

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3.2.2 The sealing between the heater and the mounting surface must
be intact.
During installation, the sealing gasket provided by the
manufacturer must be used, and the mounting surface must be
flat.
Four M6 nuts provided by the manufacturer shall be used for
securing the unit at 6-7Nm. Note: When the heater is
reinstalled, the gasket must be replaced.

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3.2.3 If the thickness of the installed panel is less than 1.5mm, an
additional reinforcing plate must be installed.
3.2.4. After the installation of the heater, make sure there is no
obstruction at the air inlet and outlet.
3.2.5. When a hose is connected to the hot air outlet, the inner
diameter of the hose shall not be less than 60mm, and the
material must have a temperature rating higher than 130 °C.
3.2.6. The maximum pressure difference between the intake side and
the outlet side of the heater shall not be greater than 0.15 KPa.
3.2.7. The hot air outlet shall not be directed towards the non-heat-
resistant parts.
3.2.8. When the heater operates in external circulation mode, no
water and debris shall enter the cold air intake.

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3.2.9. When the heater operates in internal circulation mode, the hose
placement needs to prevent heated air from entering the air
intake again. The intake air should always come from the cooler
area.

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3.3 Installation of fuel supply system
The fuel supply system of the heater is shown in the following figure.
3.3.1 The clip with rubber sheath shall be used to secure the fuel
pump. The outlet of the fuel pump should be inclined upward at
15~35 degrees. The fuel line from the fuel pump to the heater
shall rise gradually.

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3.3.2 The installation location of the fuel pump shall avoid high
temperature components. Do not use the fuel pump at a
temperature higher than 20 °C.
3.3.3 The height difference between the fuel level and the fuel pump
and the height difference between the fuel pump and the fuel
inlet of the heater will generate pressure in the fuel line. As a
result, these dimensions should meet the following
requirements: a ≤ 3m, b ≤ 0.5m, c≤2m. (b ≤ 0.15m is required
for a sealed fuel tank due to negative pressure)
Note:
1. Check the air vent of the fuel tank during installation.
2. After the fuel line is cut, ensure that the nozzle shape is
regular and will not affect the fuel supply.
3.3.4 Installation of fuel filter
The fuel filter must be installed before the inlet of the fuel
pump. Notice the fuel flow direction icon. It should point

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upward at 0-90° as shown. The fuel filter needs to be replaced
every two years and the fuel line connector and clip must be
replaced at the same time.
3.3.5 Installation of fuel line
3.3.5.1 The fuel pipe shall be installed to prevent scratching and hitting
by sharp objects and debris. It should be installed away from hot
components of the vehicle. If necessary, nylon corrugated
sleeves and other protective accessories shall be installed. The
fuel line must be secured with zip tie, and the distance between
zip ties shall not be greater than 100cm.
3.3.5.2 To prevent air from entering the fuel line, use the stock rubber
connectors and clamps to connect fuel lines. Bubbles shall be
prevented at the connection (See figure below).
A Correct B Wrong

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3.3.6 Installation of fuel standpipe
3.3.6.1 When the fuel is drawn from the fuel tank of the vehicle, the
fuel standpipe shall be used. The installation hole on the fuel
tank (or fuel tank cover) is φ 25 ± 0.2mm, with neat edges and
flat surroundings to ensure a good. The distance between the
lower end of the standpipe and the bottom of the fuel tank
should have a minimum distance of 25mm.
3.4 Installation of electrical components
3.4.1 The heater control switch is connected to the 4pin connector.
Do not install the control switch right near the hot air outlet or
the cabin door to avoid constant turning on and off at
thermostat mode.
3.4.2 A 20A fuse is used at the in-line fuse box. The red and black
cable connect to the power supply.
3.4.3 The fuel pump connector is not installed for easier routing
through the floor. Install the connector by inserting the wires all
the way into the connector until hearing a click. The fuel pump
cable is non-polarized. Installing the connector is irreversible.

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3.5 Installation of air intake and exhaust pipe
3.5.1 The air intake pipe of the heater is an aluminum coated plastic
corrugated pipe. It connects to the air intake of the heater and
is secured with the clamp. The air intake must be placed outside
the vehicle and away from any other exhaust.
3.5.2 The air intake pipe shall be arranged to prevent water from
entering the pipe, and prevent it from being scratched by sharp
objects. The intake pipe shall be fixed on the vehicle with the
clamp.
3.5.3 Exhaust pipe is stainless steel corrugated pipe. It connects to
the exhaust port of the heater and is secured with a clamp. The
exhaust gas from the exhaust pipe shall be discharged directly
to the outside of the vehicle. The outlet of the exhaust pipe
should be at least 4ft away from any openings on the vehicle.
3.5.4 The caps on the intake and exhaust pipes shall be intact and
shall not be damaged or removed. If the working environment
contains solid particles or dust for a long time, an air filter
should be installed
3.5.5 The exhaust pipe shall be arranged to minimize bending to
ensure smooth exhaust.
3.5.6 The outlet of the exhaust pipe shall not face the vehicle moving
direction.

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3.5.7 The intake and exhaust pipe shall be arranged so that the pipe
will not be blocked by mud, rain, snow and other objects.
3.5.8 When the heater is operating, the temperature of the exhaust
pipe is very high. The exhaust pipe should be placed away from
non-heat-resistant parts. The exhaust outlet shall point
vertically downward with an angle of 90 °± 10.
3.5.9 A heat shield should be installed if there is risk for people to
touch the exhaust pipe.
3.5.10 The air intake pipe and exhaust pipe shall always bend
downward. Otherwise, a φ 5mm condensate drain hole shall be
opened at the lowest point of the pipe. If bending is required,
the bending radius of the pipe shall not be less than 50mm. In
addition, the sum of all bending angles shall not exceed 270°.
Note: Turning off the heater directly by cutting off the power is
strictly prohibited. It could cause carbon build-up in the burner and
damages to the accessories.

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IV. Operation
4.1 Basic Operation
To turn on/off the unit, long press 2s at temp mode/ power mode
screen. When the unit is turned off, note that the actual fan on the
unit will not stop until the heat exchanger reaches a safe
temperature. To switch between modes and pages, short press the
knob and the screen will cycle through all the pages. To change the
setting in a page, turn the knob to move the cursor till the target
option is flashing. Short press and turn the knob to edit. To move
to the next page, move the cursor to “NEXT” and short press.
4.2 Start the heater for the first time
For fuel line within 6ft, no priming is required, and the heater can
be started as usual. It may take 2-3 tries for the fuel to reach to
heater. For fuel line longer than 6ft, it is recommended to enter
“QUICK PUMP FUEL” page to prime the fuel line manually. See
detailed instructions in the “QUICK PUMP FUEL” section.
4.3 Temp Mode (Thermostat)
In thermostat mode, the unit will adjustment power output
automatically to the maintain the room temperature at the set
value. In temp mode page, the screen displays the following info:
cabin temperature, system time, elevation, operating status, timer
status and error codes. If there is an auto run scheduled, an alarm
clock icon will show. Long press 2s to turn/ off the unit. The fan
icon rotates when the unit is running.

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To set target temperature, rotate the dial. Once set, leave the
control switch for 3s and the new target temperature will be
saved. Display will go back to main screen and show ambient
temperature.
If the ambient temperature is four degrees higher than the set
temperature, the heater will automatically enter standby mode. At
standby mode, fan icon does not turn, and the display shows SET
TEMP REACHED. Once the temperature is three degrees lower
than the set temperature, the heater will automatically start.
4.4 Power Mode
In power mode, the unit always runs at set power output level.
There are five output levels. In power mode page, the screen
displays the following info: output level, system time, elevation,
operating status, timer status and error codes. To change the
power output, turn the dial.

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4.5 Auto Run
After the auto run is scheduled, the unit will automatically turn on
and operate in the last mode the unit was in with the previous
setting (target temperature or power output level). To schedule an
auto run, turn on auto run at “AUTO START TIME” page and set a
starting time. The second row shows the system time. When the
auto run is scheduled, an alarm clock icon will appear in the mode
page. The unit will automatically start every day at the scheduled
time till the feature is turned off. Move the cursor to “NEXT” and
press the knob to save.
In “AUTO RUN TIME” page, turn the knob to set the duration for
auto run. Move the cursor to “NEXT” and press the knob to save.
4.6 Set System Time
This page sets the time for the system. Notice the system time
resets when the power is disconnected. Move the cursor to
“NEXT” and press the knob to save.

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4.7 Quick Pump Fuel
The fuel pump can be turned on manually through this page to
prime the fuel line. Long press the knob for 2s and the fuel pump
will start. Closely monitor the fuel level in the fuel line and short
press to stop the fuel pump when the fuel gets close to the unit.
Excessive fuel in the combustion chamber could cause incomplete
combustion and difficulty in starting up.
Note: Do not allow any other way directly (cut off the power) off the
heater, will cause the burner carbon build-up and various damage to
the accessories.
To maximize the lifespan of the unit, the maximum continuous run
time is 48h. Once 48h is reached, the unit will power cycle and
continue operation.