The right choice depends on your travel season, destinations, insulation, and the layout of your build (which affects the total volume to be heated). For vans and vehicles with a living space of up to 12–14 cubic meters and for normal camping (not winter use), we generally recommend the 2kW heater, the Air 2D. (By the way, we always assume the heater and air intake are installed inside the vehicle.)

We advise against oversizing. Most people say they want to travel "occasionally" in colder months. In practice, this usually means that the main use is during the milder seasons—so the 2kW heater is typically the best choice. On the rare really cold days, you can separate the cab from the living area with a curtain or blanket—several kilowatts of heat can be lost through the windows alone.

It doesn’t make sense to size your heater for the absolute coldest extremes. If the heater runs mostly on low power, it will soot up, and there’s no warranty on sooted combustion chambers. The idea of "better get the bigger heater" isn’t always best—if the bigger heater is too powerful and makes it too warm even on the lowest setting, you’d have to open the windows and run the heater at full power every few weeks for at least 30 minutes to burn out the soot. Ideally, the heater should be sized so it runs mostly at medium or high power, which keeps the combustion chamber clean.

If you’re still unsure—if your vehicle size is borderline or if you’re planning to travel through all seasons—have a look at our Twin Kit.

Installation and operating manuals for heaters and control panels are available on the respective product pages. You can—and should—read them even before purchasing your heater.
If you’re missing our download portal with the "collected works" from our old shop, just click here ;-)

No—the room air intake (not to be confused with the combustion air intake) should always be taken from inside the space you want to heat, for several reasons. The most important: outside, you never really know what you’re pulling in or what you’re bringing into your vehicle. In the worst case, you could end up with your own heater exhaust if the wind shifts, or with a Moroccan sandstorm, or damp, chilly November fog. The heater is also much more efficient and quieter if it’s recirculating and reheating air that’s already warm, instead of constantly having to heat up cold outside air. For fresh air supply, it’s better to crack open a window or roof hatch a little—this also helps moisture and condensation escape.
Don’t worry: you’re not using up or burning oxygen from inside the vehicle this way. The combustion air for the heater’s burner comes from outside. Here, we’re just talking about recirculating the room air.

The intake side is where the fan is located. This is the same side as the cables and the fuel line. You’ll also find diagrams with arrows in the heater’s manual that show the exact locations.

In theory, yes—but in practice, **not yet**. Both the 2B and 4B already exist at the factory and have received the (e) certification mark. Unfortunately, production hasn’t started yet, and there is currently no date—not even an estimated one—for market launch or sales. As soon as there’s any news, you’ll hear about it on our social media channels or in our newsletter!

Only for the VW T5/T6 is the installation location set by the factory, so it’s always the same—and we have a dedicated T5/T6 installation kit for this. For all other vehicles, the installation location is individual, so there isn’t one single perfectly matching kit for Jumper, Ducato, and others.
With our 99% Camper Kit, we now offer a “carefree package” with various components that should fit 99% of most campervans. You’ll find more info, a comparison between different installation kits, and optional accessories in our online magazine(german language only by now, please use your translation tool).

Patience! When using the heater for the first time, this is required for several reasons.

1) Please note: the start-up process and preheating phase take a few minutes.

2) During initial use, several starts may be necessary until enough fuel has been pumped. Error 13 (insufficient fuel supply) may occur a few times.

3) A new heater will initially smell new or smell like rubber for a while. This is completely normal as the plastic parts gradually warm up. The heater also needs to be given some time until the smell dissipates after a few days of operation.

The heater has an E-mark and therefore does not require separate registration. The mark can be found on the heater itself. The Autoterm Air comes with a duplicate sticker on the heater, for attachment to a more accessible location if the heater is hidden.

First of all, the heaters are significantly quieter than other models or similar air heaters a few years ago. If they're still too loud for you, you have a few options.
For, or rather against excessive noise from the combustion engine outside, every heater comes with an exhaust silencer. Our Supersilent exhaust silencer is also available as an option.
However, more important to many is the noise level in the vehicle. They are therefore even considering installation underneath the vehicle, which we strongly advise against in most cases; see the topic "Underfloor Installation." The warm air has to reach the vehicle and be circulated there one way or another; there will always be some noise from the airflow. It is comparatively low, but the manufacturer does not provide a decibel rating. To reduce the noise of the interior air, we have our Schlafgut warm air silencers.
The pump also has to work if the heater is to do its job, and it can't do this completely silently. For sensitive users, Autoterm launched extra-quiet pumps at the end of 2018, which are now included in all heaters. To achieve this quietness, however, they must be vented vertically, as described in the installation instructions.
However, the noise level is also influenced by how and where the heater is installed and how well it is decoupled. For example, the pump should not be attached too tightly to the transmitting parts.

Since October and November 2018, the Autoterm 2D and 44D/4D air heaters have been equipped with an altitude kit, known as the "Ural Edition," as standard. Further information can be found in our online magazine.
Retrofitting the altitude kit is not possible for every air heater. Newer 2D and 44D/4D models should be convertible. The first step would be to check the serial number of the heater in question for convertibility, whether an altitude kit board is compatible, and whether a different glow plug might be required. The replacement is not complicated, but must be performed by a certified Autoterm installation partner if the warranty is to be maintained.
No altitude kits are currently available or planned for Binar/Flow and similar models.

Since November 2025, Autoterm has officially approved HVO100 fuel for its diesel heaters. Read more in our online magazine.

Insulation is necessary if the exhaust pipe passes through potentially fire-hazardous areas. However, the installation location should be chosen so that nothing poses a heat hazard.
Therefore, there is no absolute requirement for the operation of the heater itself, but insulation should be used if 1) it is routed along potentially fire-hazardous areas, as already mentioned, and 2) if the exhaust system is not installed at a downward slope. In the latter case, insulation can at least reduce the formation of condensation (often used on boats).
In vehicles, insulating the exhaust pipe is really only relevant for external heat protection.

According to the installation instructions, a condensate drain must be drilled into the included Autoterm exhaust silencer to prevent condensation from accumulating. This is especially necessary if the exhaust system is very long and/or the silencer is installed "downward." Shorter exhaust systems generally do not have this problem.

Yes and no. In heating mode, the fan speed is inevitably linked to the heating output. Therefore, if the heating output is reduced, the fan speed also decreases.
In fan-only mode, the fan speed can be controlled using the bar graph (PU27) or the rotary control (PU5).

The pump cable is not yet fitted with a connector to facilitate routing through the body; one is included. Polarity is irrelevant, as this is a magnetic pump.

All vehicles have openings of various sizes with rubber plugs in the body that can be used to route the pump cable. These openings are often located under the driver and/or passenger seat.

The 2D has a rated power of 29 watts at its highest setting and 10 watts at its lowest. This is comparable to a license plate light bulb.
Nevertheless, it is recommended to install a second battery to prevent the starter battery from being drained.
The 44D or Air 4D is specified with an output of 10-62 watts.

The fact that our heater descriptions do not mention the battery required for the heater is that many factors influence this calculation. Most users connect not only the heater to a second battery, but also other devices. In addition, there are many different battery types, and the ambient temperature also has a significant influence on the battery's usable capacity.
Let's consider the following example: We assume that a standard lead-acid battery is to be installed exclusively for the auxiliary heater. We also assume that a 2kW diesel heater will run at full power for 10 hours per night. The heater's maximum electrical power consumption is 29 watts. If we calculate with 12V, this results in a current of 30W / 12V = 2.5A. After 10 hours of nighttime operation, 25Ah will be consumed.
With a standard lead-acid battery, only 50% of its capacity is actually usable at room temperature anyway, and we also add a safety buffer of 30% on top. This means that with the heating usage mentioned above, we need at least 25Ah * 2 = 50Ah, and with our safety buffer, we end up with 50Ah * 1.3 = 65Ah of required battery capacity.
Note that this is at normal room temperature! If the battery is installed outdoors and is cold, its capacity can be much lower, for example, only 20% instead of 50%. That would already give you a required battery size of 160Ah! So, as a basic rule, you can already deduce: supply batteries belong in a heated interior!
For a more realistic calculation, let's assume 8 hours of sleep and 15W average power, and at room temperature, we arrive at a lead-acid battery of at least 26Ah for an 8-hour night.
With other battery types (especially lithium), things look better, because not just 50% but perhaps even 90% of the capacity is usable. Our "realistic" night above would probably be easily survivable with such a battery with 15Ah ;)

In addition to the general power consumption during operation, you also have to consider that the heater requires more power during the start-up phase. When the device starts up, the glow plug is operated for 2 minutes, which requires up to 11A at 12V. This is especially relevant if you want to operate your heater with a power box. In this case, you should make sure that the power box you want can deliver more than 10A at the DC output; otherwise, it will shut down with an overload warning, leaving the vehicle cold.

Unfortunately not. The heaters come in a sealed package. Kit components cannot be exchanged.
The SuperSilent exhaust silencer and similar components are optional accessories and are independent of the heater kit.

The Autoterm Comfort Control and the PU-27 OLED display have an integrated temperature sensor. A second one can be connected, but is not required. This is useful if you want to set up a second heating zone, such as in the retractable roof, and set the reference value for the heating temperature control there, for example, when going to bed. Or if the control panel is installed in a location where it cannot provide a good reading.
The PU-5 does not have a temperature sensor and operates in power mode. If you want to operate it in temperature mode, an external temperature sensor must be connected.
The external temperature sensor is not included in the heating set; it must be ordered separately if you want to operate the ACC or PU-27 with two zones or the PU-5 in temperature mode.

Temperatures inside the heater can reach up to 300 degrees Celsius. The warm air outlet can easily reach 80-100 degrees Celsius. The exhaust duct and the bolts on the underside also get very hot, so we recommend our mounting flange not only for easier installation but also for thermal decoupling.
The outside of the heater itself becomes lukewarm. According to the instructions, it should be installed with 6 cm of space all around, 5 cm in front of the intake and 15 cm at the outlet. However, please do not store heat-sensitive objects too close to the heater!

Many people are hesitant to insert the fuel extraction pipe into their vehicle's tank. However, this is the cleanest solution and intended by the manufacturer. Therefore, the fuel extraction pipe is included with every heater.
If the vehicle already has an auxiliary heater, or you are certain that the return or even the supply line is usable (please check thoroughly with a workshop or manufacturer's information!), a T-piece can be inserted into the fuel line. This is not included in the heater kit.
The question about the T-piece on the return line comes up again and again. However, this is usually a short-sighted solution unless you know for sure that the return line extends far enough into the tank (not the case with the Ducato, by the way). If the return line is too short or the cross-section of the return line is unsuitable, you will not be able to enjoy your heater with "Error 13" (insufficient fuel supply).
Auxiliary tanks are actually intended for the engine compartment of boats and are prohibited in vehicle interiors in Germany. Even when installing an additional tank at other locations, the local TÜV should be consulted in advance.

Better not! We strongly recommend installation in the vehicle, as the heater would be exposed to splash water and dirt underneath the car. There are only a few vehicle types for which underfloor installation makes sense (T5/T6). In many vehicles, installation in the bench seat or passenger seat console is a good option. This also avoids drilling two approximately 7cm holes in the underbody for the interior air intake and the warm air vent. This also results in valuable heat being lost through the warm air ducting. Please also be careful not to walk away from the heater at a 90-degree angle (heat buildup).

It is very important not to reduce the diameter of the warm air duct!
The 2D has a 60mm system.
The 44D and Air 4D use a 90mm system. However, different adapters are required if you want to install the warm air duct on the warm air side and/or on the intake. You can find everything in the Warm Air Distribution, 90mm category.
Note: The grille on the warm air inlet and/or outlet of the heater must be removed by gently twisting and pulling when working with the warm air duct.

If you can't or don't want to install it yourself, or don't have the tools, workshop, know-how, or time, our installation partners can be found here.

There are now countless videos on YouTube showing how Autoterm heaters are installed, operated, and used. However, caution is advised; not all of them demonstrate proper handling as intended by the manufacturer. A good basic knowledge of automotive technology, some prior experience, and a well-equipped workshop are essential for installation. Please read the installation instructions, which can be found, for example, in our download portal. Otherwise, one of our certified and trained installation partners should be consulted.
A selection of good YouTube videos can be found on our topic page.

With the Ural Edition, the heater algorithms have become more complex, which can make them react more sluggishly depending on the air pressure. Many people are too impatient when first using the heater and think their heater isn't regulating. This shouldn't be noticeable later on during normal heating operation.
Autoterm has since adjusted the temperature and thermostat modes slightly. We recommend not setting the hysteresis too tightly, thus giving the heater some leeway for temperature regulation, and, as just mentioned, not being too impatient.
Ideally, the heater should be dimensioned so that it doesn't have to shut down heating. This is more efficient and promotes longevity than (automatic or manual) restarts.

Yes, the bracket can be mounted facing upwards or to either side, giving you complete flexibility.

When using a heater with a 90° angled warm air outlet, you should keep in mind that this is a compromise to save space – despite the best possible flow optimization of the angled piece. Therefore, avoid using sophisticated warm air ducts; instead, keep the heat dissipation short and uncomplicated. This ensures that your heater functions perfectly and does not slow down or even shut down due to heat buildup. The standard straight warm air outlet, combined with the most straight path from the heater and only gentle bends in the warm air duct, is and remains the best installation option.