Autoterm auxiliary heaters are known for their reliability, even under harsh conditions. Still, especially on long trips, a problem can come up now and then; no manufacturer’s products are immune to that.
One clear advantage of Autoterm, though, is that the simple technology is extremely repair-friendly, so even a layperson can get it running again in an emergency.
This article explains when you should equip yourself with spare parts, which ones they are, how to go about it and what to keep in mind.
Do I Need to Carry Spare Parts?
First of all: don’t worry. Your auxiliary heater doesn’t fail “just like that”. Still, certain circumstances acting over a longer period on the road can of course take their toll on any technology, including an auxiliary heater.
The Autoterm service network is better established worldwide than is often assumed. But say you’re traveling through Kazakhstan and Mongolia or through Alaska – there you find not only extremely cold nights, but also an awful lot of “nothing”. Even with the best service partner network, the nearest specialist workshop is probably several days’ travel away.
If you’re planning a bigger trip, it therefore makes sense to carry spare parts for technology that is sometimes vital for survival – this applies especially to keeping the vehicle roadworthy, but also to the auxiliary heater that has to keep you warm in freezing cold.
A decisive plus of Autoterm auxiliary heaters is therefore first of all the availability of all spare parts. Second, repairs can usually be carried out without problems even by non-professionals with some manual skill. True, the warranty lapses if you open the heater as a layperson and repair it on your own, but on nights with -35°C in the Altai Mountains you will probably give the unit working a higher priority.
How Do I Get Spare Parts?
Even though an Autoterm auxiliary heater can be repaired by a layperson in an emergency, the work still has to be done properly so that the heater works safely.
That means you should inform yourself thoroughly beforehand, have the relevant repair instructions at hand and not open the unit prematurely.
For this reason, certain spare parts in our shop are initially visible only to specialist workshops and trained installation partners. In principle, however, we carry all spare parts for Autoterm auxiliary heaters and sell them to end consumers as well.
So if you urgently need something or want to carry parts as a precaution for a planned trip, just contact our support. We will then also provide you with the necessary documents and repair manuals!
The Most Important Spare Parts for Overlanders
Below you’ll find an overview of the most common spare parts for the Autoterm Air auxiliary heaters. We would definitely recommend these for long trips:
- Gasket set
- Glow screen
- Spare glow plug
- Spare fuel pump
Additional spare parts are listed below. They are needed less often, though, so whether to take them is up to you.
Replacing and Maintaining Spare Parts
This chapter covers the most common reasons why certain components fail and the most important repair notes. We are happy to provide detailed repair documents and parts overviews on request.
Fuel Pump
The fuel pump can fail because of contaminated fuel (see our article: How to Make Your Autoterm Auxiliary Heater Ready for Overland Travel & Offroading), but also through wear and aging.
To prevent the pump’s moving parts from getting gummed up by viscous deposits and the pump failing because of it, run the heater at the highest level for 20 minutes once a month. Don’t forget this maintenance step in summer in particular: if it’s warm enough that the heater stays off altogether, the diesel sitting in the pump has especially much time to gum up the delicate moving parts.
But now it has happened and you no longer hear the typical clicking? And no fault or damage can be found in the wiring? In that case, the pump often has to be replaced.
When installing the new pump, with the extra-quiet Th11 pumps in particular, make sure to bleed them vertically before mounting.
If not all air bubbles are removed, the extra-quiet pump is as loud as a normal one. Heating output can also be negatively affected by air bubbles.
How bleeding works is described in detail on page 20 of the heater installation manual.
If there are stubborn small bubbles that just won’t go away, the pump can be triggered manually. We explain how that works here:
Combustion Chamber
The combustion chamber is rarely defective, but it can be sooted up. You notice this when the heating output keeps dropping and the heater eventually doesn’t start at all anymore.
The damage occurs when the heater has mostly been run at a low power level or at high altitude without being burned clean – like in the photo below with our workshop tiger Lukas, who is raising his finger in warning for good reason!
Running the heater at full load for half an hour at least every 14 days and thereby burning it clean is the most important maintenance tip for your heater. By far the most malfunctions are caused by sooted combustion chambers.
Cleaning requires taking the heater apart. A well-stocked toolbox is enough for that, but the gasket set 37489 should be ready, since the main gasket is often damaged.
The cleaning itself is straightforward, if a real mess: brush out the combustion chamber with an old toothbrush and then clean it with brake cleaner.
Glow Screen
The glow screen is a typical wear part and essential for the heater to work.
To replace it, pull it out of the glow plug tower with needle-nose pliers – this will inevitably destroy it.
The new screen is put into position with a special tool or a 5 mm socket.
Make sure it is not pressed too deep into the socket and that the side holes sit rotated by 45° relative to the holes of the glow plug tower.
Glow Plug
The glow plug is largely wear-free. Still, the contact point of the electrical connection can break. This can happen especially on rough offroad tours or washboard roads. The heater responds to this problem with an immediate Error 9.
In addition, with poor fuel quality or combustion, a film can form on the glow pin and prevent it from glowing. The plug then has to be cleaned. That is quite easy, because you can pull the deposits off the glow pin like a thimble.
Careful when choosing the glow plug: the operating voltage has changed depending on the heater’s year of manufacture, so we recommend contacting us with the serial number of the heater. We will then find the matching glow plug for you.
Additional Control Panel
If the control panel fails, the heaters have an emergency start that lets you start and stop them even without a control panel. It uses the white and brown wire on the heater’s wiring harness (see manual page 38). The wiring diagrams for the electrics can be found there.
Via the emergency switch input, however, the heater runs only at full load. Good enough not to freeze, but not very comfortable if it takes a while until you can receive a package from us or get to an Autoterm service partner.
For longer tours to remote regions, we recommend taking a simple, inexpensive Simple Control as a replacement.
Circuit Board
The circuit board of an Autoterm auxiliary heater usually only needs to be replaced when there is a serious defect that can’t be fixed by simpler repairs. Typical reasons for replacing the board can be:
- water damage,
- electronic defects (age-related failure of central components such as resistors, capacitors or microcontrollers)
- overvoltage caused by faults in the vehicle electrics.
If you have a very old Autoterm heater that may even still be called Planar, please check the serial number when contacting our support. On heaters built before 2018, the board has to be swapped for one with the altitude kit. We also sell this spare part after consultation.
Carrying the board as a spare part only makes sense on real long-term trips.
Conclusion
All spare parts for Autoterm auxiliary heaters are available in our shop, after consultation where applicable, and can generally be fitted well even by laypeople.
With the most important parts on board, nothing can go wrong on the road even on a long-term trip, and with an Autoterm auxiliary heater you will be spared cold nights caused by unavailable spare parts, missing instructions or repairs that can only be carried out in a specialist workshop.
Our technical support is happy to help with questions and individual advice.
That way you’re well equipped to travel warm and safe even in the remotest corners of the world.
Did these tips on carrying spare parts help you? Then feel free to share them with other travelers who will surely be grateful, too:
