ATG Alternative Technology Group GmbH Alternative Technology Group GmbHGerman

Fuel Preheater

The Solution for Freezing Problems with Diesel or Biofuels!


  • Suitable for Diesel, Biodiesel and Straight Vegetable Oil (SVO/PPO/WVO)

  • Prevents clogged fuel filters due to fuel gelling in winter

  • Keeps fuel fluid at extremely low temperatures

  • High efficiency by heating directly

  • Gentle engine heating - less fuel consumption

  • Economical and engine-friendly by eliminating diesel additives

  • Reduces exhaust emissions

  • TUV (German Technical Inspection Authority) approved

  • Simple and quick installation with detailed instructions

  • Suitable for diesel vehicles and engines of all kind: Automobiles, SUVs, Vans, Trucks, Buses, Tractors, Tows, Agricultural Machinery, Construction Machinery, Generators, etc.

  • Maintenance-free system

  • Proven technology - Made in Germany

The Problem ...

Diesel fuel and biofuels gel at temperatures below freezing. Paraffin crystals form in the fuel, making it gelly-like and flaky. As these suspended flakes pass through the filter, they gum up its microporous surface. Within a short period of time, the fuel will no longer flow through the filter to the injection system. The results: the engine loses power and stops running.

Adding gasoline or additives to prevent fuel gelling offers no real solution but only seem to help on a limited basis. They can have a negative effect on the engine´s performance and life cycle, not to mention, they must already be added before it turns cold.

"Winter diesel" (formulated especially for winter usage) does not guarantee a smooth running engine. Winter diesel is laboratory tested to -20 °C / -4 °F. At still lower temperatures and freezing winds, it is unclear whether the engine will even run. In any case, the engine works unregularly, resulting in a greater amount of fuel being consumed.

Once the fuel filter is clogged, only the supply of warmth can solve the problem quickly. By heating, the engine is protected when running on any fuel at any temperature and prevents greater fuel consumption.

... The Solution

The Diesel-Therm fuel preheater is a effective and permanent solution for cold problems with diesel or biofuels.

Diesel-Therm prevents the filter´s pores from clogging up at very low temperatures by warming the fuel with a small heating system, which is mounted in front of the filter. In a matter of seconds, the energy-rich paraffin crystals will dissolve and the fuel passes through the filter as if it would be summer.

Diesel-Therm - filter heater

clogged fuel filter

open fuel filter

By controlled preheating of the fuel temperature-related operating problems will be effectively eliminated from the critical part of the fuel system and fuel additives are not required anymore.

To prevent cold problems or a loss of power due to a plugged fuel filter Diesel-Therm is activated by the driver with a On-/Off-switch. The heating process is displayed by a pilot lamp and automatically regulated by a thermostat. The heating of the fuel remains as long as the heating device is deactivated over the switch.

Alternative to the fuel filter Diesel-Therm can also be installed in front of fuel pumps, solenoid valves, etc. to preheat the fuel.


Diesel-Therm is as 12 and 24 Volt model in different versions available:

Screw-/Filterversion DH for filter inlet
Diesel-Therm Screw-/Filterversion DH The Screw-/Filterversion DH is installed instead of the existing banjo screw (thread M14x1.5 or M16x1.5) at the filters entrance.

Universalversion DHS for rubber hose

Diesel-Therm Universalversion DHS
The Universalversion DHS is installed in the fuel line (flexible rubber hose) with 08, 10 or 13 mm inside diameter (ID) in front of the filters entrance.

Prices and Order

Diesel-Therm - Installation Kit
Diesel-Therm is directly from ATG available.

Following components are included in delivery: electric continuous-flow heater (12V approx. 200 W / 24V approx. 300 W), temperature switch (regulates the temperature), rotary switch with pilot lamp, relay, cable loom with connectors, fuse and protective caps, miscellaneous materials, detailed installation instructions


The company ATG has been operating in the field of fuel heating for more than 20 years. Diesel-Therm is for example used by: Atlas Weyhausen, Deutz, Faun, Honda, Iveco Magirus, Kaessbohrer Gelaendefahrzeuge, Liaz, Liebherr, MAN, Mitsubishi Motors, Nissan, Toyota.

... after careful examination of your diesel heating system we decided to equip all our ski-run rollers with Diesel-Therm.

Kaessbohrer Gelaendefahrzeug AG

Kaessbohrer Flexmobil

Meanwhile we installed Diesel-Therm in our own vehicle fleet and recognized that your product improves the operation with biodiesel noticeable at extreme coldness. It's in our interest to offer Diesel-Therm also to our customers.
Company Petrotec AG, Borken

... no more problems with freezing. Because of this experience we will offer Diesel-Therm also in the next winter season.
Company Claus Laackmann, agricultural machinery and motor vehicles

... we installed and tested several fuel heating systems. We decided to use Diesel-Therm. It is a very safe system, the heating is effective already after a short period of time. Within approximately 1 minute the troublesome smoke, which comes out of the exhaust pipe, vanishes. This is also a contribution to the environmental protection.
Company Adolf Soehner KG, Daimler-Benz Representative

... successful use of Diesel-Therm, the busses have always been ready for use, even at very low temperatures and after parking in winter sport locations, without using any flow improvement additives.
Town Council Kirchweihtal

... no longer problems with fuel gelling at our passenger cars and trucks in the local and long-distance traffic by using Diesel-Therm.
Forwarding Agency Bungenberg GmbH

Our planning department tested and released Diesel-Therm based on the last year’s experiences. It impresses by a very good price-proficiency-relation.
Iveco Magirus AG

... with Diesel-Therm the fuel consumption dropped to 3-5 liters per 100 km, the smoke formation was considerably lower.
P. Hoffmann, hauling company

... temperatures of -25° C / -13° F and your diesel heating system satisfied our requirements. We like to equip all our busses and vehicles in the bus and freight traffic with Diesel-Therm for the upcoming winter season.
Company Ludwig Ganserer, bus and short-distance haulage

FAQ - Frequently Asked Questions

Which Diesel-Therm-Version fits to my vehicle?

Due to the vast number of vehicles or engines on the market, it is almost impossible to make a type-specific statement. In case of doubt we recommend the purchase over a specialist company. Our sales team supports you in any question.

Where can I order Diesel-Therm?

Diesel-Therm can be ordered directly from ATG.

Where can I have Diesel-Therm installed?

The installation ca be performed by any reputable garage/mechanic.  Craftmanship and an understanding of diesel engines provided, a DIY (do-it-yourself) installation with the included installation notes is also possible.

Is the electrical preheating of fuel generally allowed?

For your own protection, please check with the appropriate authorities in your country. This is also to be done for any changes on the vehicle.

Is it possible to operate my vehicle with straight vegetable oil (SVO/PPO/WVO) after the installation of Diesel-Therm?

Diesel-Therm is used for preheating diesel and biofuels to prevent flow problems through clogged or plugged fuel filters. For heating-up straight vegetable oil to combustion relevant temperatures Diesel-Therm alone is insufficient. To operate diesel vehicles and motors with straight vegetable oil (SVO/PPO/WVO) our Vegetable Oil Conversion Kits are necessary.


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