Fuel preheater – with full power through the winter

DIESELTHERM Fuel heater – with full power through the winter

  • The solution for freezing problems with diesel and biofuels
  • Prevents clogged fuel filters due to fuel gelling in winter
  • Keeps fuel fluid at extremely low temperatures
  • Gentle engine warm-up – less fuel consumption
  • Economical and engine-friendly by eliminating diesel additives
  • Reduces exhaust emissions
  • Easy and quick installation with detailed instructions
  • Suitable for diesel vehicles and diesel engines of all kinds: Cars, SUVs, vans, trucks, buses, tractors, agricultural machinery, construction machinery, generators, etc.
  • Maintenance-free system
  • Proven technology – Made in Germany


The problem …

Diesel freezes at minus temperaturesDiesel 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 result: 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.

Also “Winter diesel” (formulated especially for winter usage) does not guarantee a smooth running engine. Winter diesel is laboratory tested to -20 °C. At lower temperatures and wind chill, it is unclear whether the engine will even run. In any case, the engine works unregularly, resulting in a increase of fuel consumption.

To prevent the fuel filter from waxing, only the supply of warmth can avoid the problem. Heat ensures a smooth engine operation and prevents the increased consumption in winter.


… The solution

The DIESELTHERM fuel heater is the effective and permanent solution to avoid cold problems with diesel and biofuels.

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

DIESELTHERM filter heating

DIESELTHERM filter heating

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.

DIESELTHERM switchTo prevent cold-flow problems or a loss of power due to a waxed fuel filter DIESELTHERM is activated for the winter operation by a rotary switch. The heating process is displayed by a pilot lamp and automatically regulated by a thermostat.


Installation and scope of delivery

DIESELTHERM is available as 12 and 24 Volt model in different versions:

DIESELTHERM screw/filter version DHScrew/filter version DH for filter inlet

The screw/filter version DH is installed instead of the existing banjo screw (thread M14x1.5 or thread M16x1.5) at the filters entrance. Alternative thread sizes are available on request.


DIESELTHERM universal version DHSUniversal version DHS for rubber hose

The universal version 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.


DIESELTHERM universal version DHSEUniversal version DHSE for plastic/metal pipe

The universal version DHSE is installed in the fuel line (inflexible polyamide/metal pipe) with 08, 10 or 12 mm outside diameter (OD) in front of the filters entrance by means of Ermeto compression fittings.


DIESELTHERM installation kitFollowing components are included in delivery of DIESELTHERM:

Electric continuous-flow heater (12 V, Pmax 200 W / 24 V, Pmax 300 W), temperature switch (regulates 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 active for more than 25 years in the field of fuel preheating. DIESELTHERM is for example used by: BayWa, Deutz, Faun, Fuchs, Hitachi, Honda, Iveco Magirus, Kaessbohrer, Kramer, Liaz, Liebherr, MAN, Mitsubishi Motors, Nissan, Toyota, Zeppelin.

“We have no more problems with clogged fuel filters. Because of this experience we will offer DIESELTHERM also in the next winter season.”
BayWa AG
“After careful examination of your diesel heating system we decided to equip our snow groomers with DIESELTHERM.”
Kaessbohrer Gelaendefahrzeug AG
“Meanwhile we installed DIESELTHERM 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 DIESELTHERM also to our customers.”
“At temperatures of -25 °C DIESELTHERM satisfied our requirements. We have no more cold-flow problems in our machinery.”
Anton Vihl construction machinery service
“With DIESELTHERM our vehicles 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
“Our planning department tested and released DIESELTHERM based on the last year’s experiences. It impresses by a very good price-proficiency-relation.”
Iveco Magirus AG
“We have no longer problems with fuel gelling at our passenger cars and trucks in the local and long-distance traffic by using DIESELTHERM.”
ATB Swiss
“With DIESELTHERM the fuel consumption dropped noticeable and the smoke formation was considerably lower.”
Auto-Klinik Hoffmann


FAQ – Frequently asked questions

Which DIESELTHERM version fits to my vehicle?
Where can I order DIESELTHERM?
Where can I have DIESELTHERM installed?
Is the electrical preheating of fuel generally allowed?
Is it possible to operate my vehicle with straight vegetable oil (SVO/PPO/WVO) after the installation of DIESELTHERM?