AUTOTERM
AUTOTERM Air 4D – 4 kW heater kit with installation kit
Choose greater heating capacity when the actual heat demand exceeds the 2 kW class.
- 1.0–4.0 kW of air heating for a suitably sized fixed installation.
- Heating away from shore power using diesel and a 12 or 24 V supply.
- Choose Comfort Control for thermostat control and timers; the controller supplied depends on the selected variant.
I can help check the heated space, insulation and air distribution before you choose. More kilowatts is not automatically a better match.
Does this product suit your needs?
How to use the size guidance
This is SejlStrøm’s suggested starting point for normal insulation, not a manufacturer guarantee or a calculation for year-round use. The area refers to the interior space to be heated. Boat length is only a rough way to narrow down the choice and cannot be converted directly to m². For freezing conditions, large glazed areas, multiple cabins or living aboard all year, I calculate the requirement for the specific installation.
AUTOTERM Air 4D – complete heater kit – steady heat for boats, motorhomes and specialist vehicles
The AUTOTERM Air 4D complete heater kit is a compact air heater for reliable heat without shore power. Its electronic control adjusts the output as needed, and the model can run on diesel and HVO100.
What is included
Heater, fuel pump, wiring harness and standard installation parts. A control panel is included only with variants where it is selected. Always check the specific variant before ordering.
Technical details
Your selected configuration: 12 V / Comfort Control
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 12 V |
| Controller | Comfort Control |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Installation and choosing accessories
Boat length alone does not determine the required size. Follow the manual for fuel, power, combustion air and gas-tight exhaust routing to the outside.
Installation and compatibility
The Air 4D uses a 90 mm warm air system as standard. For an existing installation, check the inlet, outlet, exhaust, fuel system and power supply. A 90 mm duct connection requires the correct AUTOTERM adapters.
💡 My advice before ordering
I recommend choosing the model based on actual heat loss and available installation space – not just maximum output. Send me the boat type, length, insulation details and a few photos of the mounting area, and I will help you choose the right variant and the necessary accessories.
Accessories compatible with the AUTOTERM Air 4D
Selected, optional accessories. Check what is included with the selected variant and what your installation requires before ordering extra parts. This list is not a complete bill of materials for every boat or camper.
- AUTOTERM Flexible mounting bracket for Air 2D and Air 4D — adaptable mounting
- AUTOTERM External temperature sensor, 5 m, for AUTOTERM Air — temperature measurement with a 5 m cable
Spare parts for the AUTOTERM Air 4D
For servicing and replacement – not mandatory additions to a new heater. This is a checked selection. Individual parts may already be included in a gasket kit, so do not order all the parts together without checking.
See the selected spare parts for the Air 4D
- AUTOTERM Gasket kit for Air 4D
- AUTOTERM Glow plug screen for Air 2D and Air 4D
- AUTOTERM Ceramic temperature sensor gasket – Air 2D, 4D, 8D
- AUTOTERM Housing clips for Air 2D and Air 4D
- AUTOTERM Outlet grille for Air 4D
- AUTOTERM Heater mounting seal for Air 4D
- AUTOTERM Temperature sensor washer – Air 2D, 4D, 8D
If your heater develops a fault, I can help identify the spare part from the model, serial number and symptoms. Parts restricted to certain serial numbers are not included as general add-ons.
Full product description
Select voltage and control panel
The kit includes the heater and standard installation parts. If selecting "Without panel", a control panel is not included. A compatible panel is required to operate the heater. If you choose a panel variant, the selected panel is included.
Hot air ducts, outlets, and boat-specific installation parts are selected based on the installation. See control panels and marine installation kits for Air 2D and Air 4D.
Quick choice – is this right for you?
Choose this if you want: a complete AUTOTERM Air 4D base solution for fixed installation, when the 2 kW class is too small and you want a more powerful solution with documentation and access to spare parts.
- Type: complete heater kit for fixed installation
- Output: 4 kW class
- Voltage: select the correct variant
- Good for: larger heated areas or higher heat loss than the Air 2D
Before ordering: size based on the actual heated area and winter use. Boat-specific hot air distribution, hull bushings, and individual installation parts still depend on the specific installation.
AUTOTERM Air 4D – 4 kW heater kit with installation kit – stable heat for boats, motorhomes, and special vehicles
The AUTOTERM Air 4D – 4 kW heater kit with installation kit is a compact air heater for those who want reliable heat without shore power. The electronic control adjusts the output as needed, and the model can be used with diesel and HVO100.
Guideline sizing
Heated area: 11–20 m²
Boat length: 31–40 feet
This is SejlStrøm's indicative first choice for normal insulation, not a manufacturer warranty or a calculation for year-round use. The area is the internal space to be heated. Boat length is only a rough sorting aid and cannot be directly converted to m². In case of frost, large glass areas, multiple cabins, or year-round living, I calculate the needs specifically.
⚡ Practical benefits
- 1.0–4.0 kW heat output with stepless regulation
- Low consumption and operation on 12 or 24 V depending on variant
- Original AUTOTERM solution with access to spare parts and documentation
- Complete starting point for a new installation
⛵ Suitable for
- Boats where the calculated heat loss matches the heater's output and ducting
- Larger motorhomes, vans, buses, and workspaces
- Installations with multiple hot air outlets
📊 Specifications
| Heat output | 1.0–4.0 kW |
|---|---|
| Air volume | 70–168 m³/h |
| Fuel consumption | 0.12–0.51 l/h |
| Voltage | 12 V or 24 V – selected as a variant |
| Dimensions | 402 × 157 × 188 mm |
| Max. operating altitude | Up to 4,200 m |
📦 Package contents
Heater, fuel pump, wiring harness, and standard installation parts. Control panel is only included in the variants where it is selected. Always check the specific variant before ordering.
🔧 Installation and compatibility
The Air 4D uses a 90 mm hot air system as standard. For an existing installation, check the intake, outlet, exhaust, fuel system, and power supply. 90 mm duct connection requires the correct AUTOTERM adapters.
📄 Manuals and documentation
- Official product information
- Official manual or document 1
- Official manual or document 2
- Official manual or document 3
- Official manual or document 4
💡 My advice before ordering
I recommend choosing a model based on the actual heat loss and installation space – not just maximum output. Feel free to send the boat type, length, insulation, and a few pictures of the mounting area, and I will help you choose the right variant and the necessary accessories.
Accessories compatible with the AUTOTERM Air 4D
Selected, optional accessories. Check the contents of the chosen variant and your installation needs before ordering extra parts. The list is not a complete list of materials for every boat or camper.
- AUTOTERM Flexible mounting bracket for Air 2D and Air 4D — for custom mounting
- AUTOTERM External temperature sensor, 5 m, for AUTOTERM Air — temperature measurement with 5 m cable
Spare parts for the AUTOTERM Air 4D
For service and replacement – not mandatory purchases for a new heater. This is a verified selection. Individual parts may already be included in a kit, so do not buy all parts indiscriminately together.
See selected spare parts for the Air 4D
- AUTOTERM Gasket set for Air 4D
- AUTOTERM Glow plug screen for Air 2D and Air 4D
- AUTOTERM Ceramic gasket for temperature sensor – Air 2D, 4D, 8D
- AUTOTERM Cabinet clips for Air 2D and Air 4D
- AUTOTERM Outlet grille for Air 4D
- AUTOTERM Mounting seal for Air 4D
- AUTOTERM Washer for temperature sensor – Air 2D, 4D, 8D
In case of heater faults, I help identify the spare part based on model, serial number, and symptoms. Parts with serial number restrictions are not included as general accessories.
Service and repair of your heater
Is your existing diesel heater acting up? I also provide service, troubleshooting, and repair by appointment. Read about service and describe the problem with your heater →
Your selected configuration: 12 V / Without panel
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 12 V |
| Controller | Without panel |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Your selected configuration: 12 V / Mini Control
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 12 V |
| Controller | Mini Control |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Your selected configuration: 12 V / Comfort Control
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 12 V |
| Controller | Comfort Control |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Your selected configuration: 12 V / Touch Control
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 12 V |
| Controller | Touch Control |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Your selected configuration: 24 V / Without panel
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 24 V |
| Controller | Without panel |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Your selected configuration: 24 V / Mini Control
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 24 V |
| Controller | Mini Control |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Your selected configuration: 24 V / Comfort Control
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 24 V |
| Controller | Comfort Control |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.
Your selected configuration: 24 V / Touch Control
| Model | AUTOTERM Air 4D |
|---|---|
| Heat output | 1.0–4.0 kW |
| Warm-air flow | 70–168 m³/hour |
| Fuel consumption | 0.12–0.51 litres/hour |
| Voltage | 24 V |
| Controller | Touch Control |
| Fuel | Diesel EN590 or HVO100 EN15940, according to the manufacturer. |
| Heater unit dimensions | 402 × 157 × 188 mm |
| Heater unit weight | 5.5 kg, excluding the installation kit. |
| Operating altitude | Up to 4,200 m with the manufacturer’s altitude-compensating control unit. |
Size the heater according to heat loss, insulation and air distribution. Multiple cabins and winter use require an assessment of the specific installation.
Check compatibility and limitations
Check model, voltage and variant before ordering.
Selected, documented parts for this heater model. Accessories are optional; spare parts are for servicing. Check the package contents before buying additional parts.
The accessories list is a selection of compatible options, not a complete installation list. Brackets and housings are different mounting options; buy only the solution that suits the installation. Always check the package contents. Spare parts are for servicing.