All-In-One Portable Diesel Heater Instructions Manual with Images

This guide is designed to help you install, operate, and maintain your all-in-one diesel heater safely and correctly. While caravans are used as the main example throughout this page, these heaters can also be used in camper trailers, vans, motorhomes, sheds, garages, workshops, and other similar spaces where hot air is needed and the heater can be positioned safely.

All-in-one diesel heaters combine the heater body, controller, and fuel tank into one main unit. This makes them simpler to set up than standard split diesel heater kits, but proper placement, safe exhaust routing, stable power supply, and correct airflow are still essential.

Important Safety Information

Please read these instructions fully before using the heater.

• The heater must be installed and used in a stable, well-ventilated location.
• The unit should normally be positioned outside the caravan, camper, or enclosed space, with only the hot air ducted inside.
• The exhaust must always discharge outside and away from doors, windows, vents, annexes, awnings, and people.
• Do not use the heater inside a living room, bedroom, or other enclosed residential space without proper ventilation and safe exhaust routing.
• Do not place the heater near flammable items, fuel containers, fabrics, dry grass, plastics, paper, or other heat-sensitive materials.
• Do not block the hot air outlet, air inlet, combustion air intake, or exhaust.
• Do not touch the exhaust, silencer, or hot air outlet during operation or immediately after shutdown.
• Turn the heater off before refuelling.
• Use clean diesel fuel only.
• Do not run the heater directly from a battery charger. Use a fully charged 12V battery.
• Do not abruptly disconnect power while the heater is running. Always allow it to complete its shutdown cycle.

Applications

This all-in-one diesel heater is suitable for heating air in places such as:

• Caravans and camper trailers
• Vans and motorhomes
• Truck cabs
• Boats, where allowed and installed correctly
• Sheds, garages, and workshops
• Outdoor camp setups where the heater remains outside and the warm air is ducted in

These heaters are not intended for direct drying of clothes, heating animals directly, or long-term indoor residential heating.

How The Heater Works

The heater uses diesel fuel and 12V power to ignite and maintain combustion inside the unit. A fan then blows air across the heat exchanger and pushes warm air out through the hot air outlet. Fresh combustion air is drawn in through the intake, and exhaust gases are expelled through the exhaust pipe and silencer.

Because the unit combines several functions in one housing, correct setup is very important:

• Fresh air must be available to the heater
• The hot air outlet must remain clear
• The exhaust must be routed safely
• The power supply must be stable
• The fuel line and pump must work correctly

Main Components

• Heater unit: The main body containing the combustion chamber, fan, controller, and fuel tank (installed internally)
• Controller: Used to turn the unit on and off and adjust settings
• Hot air outlet: Where heated air exits the unit
• Air inlet: Where the heater draws room or ambient air to heat
• Combustion air intake + filter: Air used to burn fuel 
• Exhaust outlet: Expels combustion gases outside
• Fuel tank: Holds diesel (installed internally)
• Fuel pump: Pulses diesel from the tank into the heater (installed internally)
• Fuel line and filter: Carry and protect fuel flow (installed internally)
• Silencer: Helps reduce exhaust noise
• Power harness: Connects the heater to the battery

External Structure:

Internal Structure:

Before You Begin

Before installation, check that all parts are present and undamaged. If any components appear bent, cracked, broken, incorrectly wired, or incomplete, do not continue until the issue has been resolved.

Before first use, confirm:

• You have clean diesel available
• You have a fully charged 12V battery
• You have safe clearance around the heater
• You have a clear plan for the hot air duct, combustion air intake, and exhaust
• You understand where the heater will sit during use

Recommended Caravan Setup

For most caravan users, the safest and simplest setup is to keep the all-in-one heater outside the caravan and duct the warm air inside.

Typical options include:

• Placing the heater on the ground beside the caravan
• Placing the heater in a front toolbox or protected drawbar box, if there is enough safe ventilation and heat clearance
• Using a dedicated wall or floor duct entry if you want a neater semi-permanent setup
• Running the hot air duct through a slightly open window, hatch, or purpose-made vent for temporary use

The heater body itself should not normally be sitting loose inside the caravan cabin. The unit produces heat, draws combustion air, and emits exhaust, so it is much better suited to external use with controlled ducting.

Choosing A Safe Location

When selecting a position for the heater, choose a spot that is:

• Flat and stable
• Protected from direct rain 
• Well ventilated
• Away from foot traffic and trip hazards
• Away from children and pets
• Away from fuel cans, gas bottles, fabrics, and other flammable materials
• Far enough from the caravan that exhaust cannot re-enter windows or vents

Also make sure:

• The hot air outlet is not obstructed
• The air inlet has enough space around it to breathe
• The combustion air intake will not suck in dust, mud, or road spray
• The exhaust can be routed away safely

Installation Orientation

The heater should be installed and used in a horizontal position. Do not run it lying on its side or tipped over. Make sure all feet sit evenly and the body is stable before operation.

Hot Air Duct Installation

The hot air outlet is the part that sends warm air into your caravan or space.

Step By Step

1. Choose where the warm air will enter the caravan or space.
2. Measure the duct length needed and keep it as short and straight as possible.
3. Avoid unnecessary bends, crushed sections, or kinks.
4. Connect the duct securely to the hot air outlet.
5. Secure the other end where warm air is to be discharged.
6. Make sure the outlet is not aimed directly at bedding, pets, plastics, clothing, or anything heat-sensitive.

Important Tips

• Shorter ducting gives better heat and airflow.
• Long ducting and sharp bends reduce performance.
• If using a window or hatch entry, keep the opening neat and stable so the duct does not move around.
• If using a floor or wall entry, ensure edges are protected and sealed properly.

Air Inlet Considerations

The heater must also draw in air to heat. On many all-in-one units, this is through the front or side intake opening on the heater body.

• Do not block the air inlet
• Keep at least 20 cm of clear space around the intake where possible
• Do not place the inlet face directly against walls, storage boxes, canvas, or gear
• Keep the inlet free of dust, leaves, pet hair, and other debris

Combustion Air Intake And Exhaust Installation

The combustion air intake and exhaust are separate from the hot air ducting. These parts are directly related to the burner, not the cabin air.

Combustion Air Intake

• Install the combustion air intake securely facing sideways or slightly downward
• Add the air intake filter with provided clamps
• Keep it away from dirt, standing water, spray, and exhaust outlets
• Do not allow it to suck in fumes from the heater exhaust or from the vehicle’s exhaust

Exhaust

• Connect the exhaust pipe securely to the exhaust outlet, ideally on slight downward angle to avoid condensation (this may require raising the heater off the floor)
• Fit the silencer to the end of the exhaust pipe with provided clamps
• Route the exhaust so it points safely away from people and structures
• Keep it away from windows, doors, vents, awnings, annex walls, and underbody cavities where fumes may collect
• Make sure the exhaust does not discharge under the caravan floor in a way that could allow fumes back in
• Do not allow the exhaust pipe to contact plastics, wiring, fuel lines, or other heat-sensitive parts

The exhaust and silencer get very hot. Use care when choosing the route and location.

Fuel Tank, Fuel Line, Filter And Pump

Although the all-in-one heater has an integrated tank, the fuel still needs to travel correctly through the line and pump to reach the heater.

Fuel

• Use clean, fresh diesel
• Use fuel suitable for the season and ambient temperature
• Do not use contaminated or old fuel
• If fuel has been sitting exposed to heat for long periods, replace it with fresh diesel

Fuel Line

• Ensure the fuel line is fully connected and clamped where required
• Keep it away from hot exhaust parts
• Avoid kinks, crushing, rubbing points, or sharp bends
• Check that the line is properly seated into the filter and pump connections
• If your setup uses rigid white line, use the rubber joiners where required

Electrical Wiring

This is one of the most important sections.

The heater should be connected directly to a fully charged 12V battery. Stable voltage is essential. Poor wiring and battery chargers are among the most common causes of startup issues and error codes.

Important Rules

• Connect positive to positive and negative to negative
• Do not reverse polarity
• Do not use thin, undersized wiring
• Do not run the heater directly from a battery charger
• Do not test through unstable power supplies
• Ensure all plugs are fully seated
• Keep wiring away from hot parts, sharp edges, moving parts, and water

For Caravan Users

• Connect directly to the caravan battery where possible
• Do not use a battery charger simultaneously (charge the battery first)
• If possible, isolate solar input while diagnosing faults
• Turn off other heavy 12V loads during startup testing

If the heater is wired through poor connections, long light-gauge cable, shared circuits, or unstable charging systems, it may start the fan but fail to ignite properly.

Using The Portable Heater With A Tent

All-in-one diesel heaters can also be used with tents, as long as the unit remains outside and only the warm air is ducted inside.

• Always place the heater on stable ground outside the tent
• Run the hot air duct through a vent, door gap, or opening
• Keep the duct short and avoid sharp bends
• Ensure the exhaust is directed away from the tent and openings
• Keep the combustion air intake clear and away from dust or water
• Maintain some ventilation inside the tent
• Keep it under a cover, shelter or awning as shown in the image below.

This setup works well for canvas tents, awnings, and camping shelters, providing safe and effective heating when installed correctly.

First Start Procedure

The first startup may fail one or more times. This is normal because the fuel line may be empty and the pump needs time to draw diesel through.

Step By Step

1. Fill the tank with clean diesel.
2. Connect the heater to a fully charged 12V battery.
3. Check that the ducting, intake, and exhaust are connected properly.
4. Turn the heater on by pressing the power button on your LCD controller panel
5. Allow it to attempt startup.
6. If it stops, turn it off and try again.
7. Repeat a few times as needed until fuel reaches the heater and ignition succeeds.

A small amount of white smoke during first startup is normal while the system begins burning correctly and any residues burn off.

Manual Fuel Priming

Many of the standard 5-button black controllers used with these heaters support a hidden manual fuel injection mode.

How To Prime

1. Make sure the heater is turned off.
2. Press and hold the DOWN button.
3. While holding DOWN, press the OK / Confirm button.
4. The display should show H-OFF.
5. Release the OK button first, then release the DOWN button.
6. Press the UP button to start manual fuel injection.
7. The display should show H-ON and the pump should tick.
8. Stop priming once fuel has reached the heater.

Important

• Do not over-prime
• Too much fuel can flood the combustion chamber
• If the pump does not tick at all, the issue may be electrical rather than fuel-related

Normal Operation

Once running properly, the heater will warm the air continuously. When the target temperature is reached, these heaters usually throttle down rather than turning completely off.

This means:

• The fan speed may reduce
• The pump ticking may slow down
• The heater can continue to blow warm air at a lower rate

In small caravans or very well-insulated spaces, the area can still become quite warm even after the heater has reduced output. Slight ventilation may help in those situations.

Shutdown Procedure

Always turn the heater off using the controller. Do not disconnect the battery or pull the plug while it is running. The heater needs time to cool itself down properly during shutdown.

Maintenance

Regular maintenance will improve reliability and reduce carbon build-up.

Before Each Use

• Check the fuel level
• Inspect the fuel line for leaks or rubbing points
• Check the air inlet and outlet for blockages
• Inspect the exhaust routing
• Check that wiring is secure
• Make sure the unit is stable and level

Monthly Or Regular Use

• Run the heater on high for 10 to 15 minutes
• Inspect the pump mounting and angle
• Check the filter condition
• Clean dust from the air inlet and surrounding areas

After Dusty Or Outdoor Use

• Check the intake filter
• Inspect the exhaust and silencer
• Remove dirt, grass, leaves, and dust from the housing and openings

Long-Term Storage

• Store in a dry place
• Drain old fuel if it will sit for a long time
• Protect openings from insects and rodents
• Before using again, inspect all hoses, wiring, and intake/exhaust parts

Troubleshooting

The Heater Does Not Start

• Check that there is fuel in the tank
• Check that the battery is fully charged
• Check that the fuel pump is connected and ticking
• Check all wiring plugs
• Check the fuse
• Check that the exhaust and intake are not blocked
• Check that the fuel line is primed

The Fan Starts But The Heater Stops

• Fuel may not be reaching the heater yet
• The pump may not be ticking
• Voltage may be dropping during startup
• The heater may be connected to a charger instead of a stable battery

No Ticking From The Fuel Pump

• Check pump wiring
• Check controller and harness plugs
• Check battery voltage
• Check whether a charger is connected
• If there is still no ticking, the pump may be faulty

White Smoke At Startup

• A small amount can be normal, especially on first use
• Heavy or repeated smoke may indicate flooding, poor ignition, bad fuel, or low voltage

The Heater Starts Only On High Settings

• This can point to carbon build-up
• Dirty fuel may also contribute
• Check glow plug and combustion chamber if needed

Error Codes

Different controller versions may display errors slightly differently, but these are common meanings used with this style of heater:

• E03: Glow plug or ignition plug issue
• E04: Fuel pump failure
• E05: Overheating or sensor issue
• E06: Motor or fan issue
• E07: Wiring harness or connection issue
• E08: Flame out, often related to fuel delivery, combustion, air in line, or unstable voltage
• E09: Sensor failure
• E10: Ignition failure, often related to fuel blockage or poor fuel flow

Helpful Tips

• For quiet caravan use, place the unit on a stable surface outside and keep the duct short
• Mount the pump correctly to reduce ticking issues
• Fresh diesel is always better than old fuel that has been sitting in the sun for months
• If diagnosing an issue, test directly from a fully charged battery with no charger connected
• If the heater works on high but not low, maintenance may be needed
• Run the heater on high regularly to reduce carbon build-up

More Information

This all-in-one heater is a very practical option for caravans and other mobile or outdoor setups when installed correctly. The most important things are safe exhaust routing, clear airflow, correct pump angle, fresh fuel, and a stable 12V power supply.

If installed and maintained correctly, these units can provide reliable heat in caravans, camper trailers, vans, sheds, and other similar environments.

For more information, visit our Diesel Heater Information Pack for instructions guide, installation photos and tips, FAQs, LCD controller instructions and more.

Need Parts?

We stock all common diesel heater parts including glow plugs, mesh screens, fans, fuel lines, filters, and upgraded silencers. Check them out here:

ontrackoutdoor.com.au - Diesel Heater Parts

If you got questions or need help choosing parts,  get in touch with our team, we're here to help. You can contact us via info@ontrackoutdoor.com.au or Messenger.