Eberspacher heater OEM fitting


Well-known member
Does anyone on here have a factory fitted auxiliary (air) heater fitted?

I'm in the process of fitting an Eberspacher D4 under ours and would like to know the diameter of the heating air input end of the OEM heater. If my D4 is the same as the OEM one then I will be looking to use the factory fitting to the front door step.

When I've got all the brackets / part numbers / prices I will post it all on this thread.

Before I order the brackets. Does anyone know if an Eberspacher D4 fits in the OEM brackets or are they only designed for a D2?

I have enquired the price of the following...

MAN prices come out at least 30% cheaper than VW by what I have managed to find yet.
Right, as nobody has answered this question I have taken the bull by the horns and ordered the brackets from MAN.

However the next question is...

Eberspacher in OEM position after market fitment. I have not yet decided on the air ducting either in or outgoing. I have enquired the price of the connection between the heater and the drivers front step (VW Part No 2N0 819 219) but not yet received a price.

I would love to hear how others have tackled the ducting and outlet possibilities. My heater is a D4 Airtronic so has a 90mm inlet & outlet.
Now all parts are delivered except for item 11 (top picture) and I can answer my own question. Yes the D4 Airtronic does fit the brackets.

The missing item is just a thick rubber washer which I have a quantity of in my garage if only I could find them!

Moral of story with buying parts is to go to MAN not VW, these items were almost half the price from MAN than I was quoted from VW!

I've investigated the fitment of this assembly to the chassis of the vehicle and see that it all hangs from four either large self tapping bolts or maybe Rivnuts & setscrews, there are simply four holes at present which line up with the holes in the bracket which are for 6mm setscrews or self tappers. My aim is to fit Rivnuts in the chassis.

The ingoing air duct on the heater is 75mm diameter which, as far as I can ascertain is the same as the factory fitment that connects to the drivers door step so now a decision on either purchasing that at £100 plus or using flexible duct (which I have in stock) and a round fitment in the door step side.

The outgoing heated air outlet on my heater is the straight 90mm version, that cap is interchangeable with others that are commonly available. Current thoughts are to split the output beyond the heater and feed one up under the driver's seat and point rearwards. The other to extend back along the chassis and bring up under the rear seat with its outlet pointing towards the bed area.
I already have a Truma 4e (gas) mounted under the rear seat, the Eberspacher is to provide an alternative fuelled heating source.

Watch this space for progress as it happens!
I've just been prompted for an update on the parts and part numbers of the bracketry so here goes...


ItemVW NoMAN NoQty RequiredNotes
22N0 819 133A656194100061Bracket
34VW use pop rivets but I intend to fit 6mm Rivnuts in the chassis and use 6mm screws
42N0 819 134A656194100202Bracket
52Depending on version of Item 6 screw or pop rivet so I used 6mm screws and nylock nuts
62N0 819 379656194100081Bracket
74Part of Eberspacher kit
82I used used 6mm Rivnuts and 6mm screws
97E0 819 261656194000001Called a support but is actually a rubber washer.
107E0 819 137659303000111Bush
117E0 280 149Couldn't identify1I had a thick rubber washer acts as the silencing mounting of the bracket.
12N 906 666 040601019037618mm bolt with large washer attached, you may have these in your own stock.
132N0 819 487656194200021Plastic under shield
142 + 2With Items 4 & 8, Screws one side and 6mm nuts other.

As always don't trust my part numbers when ordering, double check with the dealer!!
April, May and part of June have passed by and now my Eberspacher D4 is installed as I envisaged in the OEM location and on the OEM brackets.

For those who don't know, I purchased a complete new un-opened Eberspacher D4 kit at what I considered to be a very reasonable price so any references to 'standard' Eberspacher parts would have been included in that kit but excluding come of the ducting.
The air ducting is all basic Eberspacher or Webasto parts with a couple of generic vents used where necessary. The ingoing air is fed via an 80mm flexible and 90 degree bend into the wall of the right front foot door step wall in a similar location to the factory fitment.

The outgoing hot air leaves the heater as a 90mm flex which bends inwards and up to a 90/60/60 fork, the vertical outlet enters the interior under the right front seat and bends to a standard 60mm Eberspacher rotatable outlet in the base of that seat frame. The fork outlet feeds an insulated 60mm tube to bring it up under the rear seat adjacent to the Truma heater (yes I have duplicate heating) to then duct rearwards towards the bed area.

The combustion side of the heater has been relatively simple, the exhaust is a very short bend of standard Eberspacher exhaust flex to join an again standard Eber silencer and then stainless stub pipe. This may prove to be too noisy and need further modification in the future. The inlet side is again standard Eber with the addition of a cheap silencer all tucked up above the heater on the brackets.

The fuel (diesel) feed begins with dropping the rear of the fuel tank as low as possible without disconnecting anything at the front of the tank. Then snipping the top off the blank tube that protrudes from the top of the tank sender unit and fitting the OEM connector and tube across the top of the tank (MAN 6561960012 £9.30 - VW 7C0 201 361C - dearer!). Somewhat more difficult is dropping the shield below the Adblue tank to mount the heater fuel pump, its mounting and it's associated pipes all of which came in the kit.
I fitted the pump in its rubber mounting bolted between the legs of the Adblue tank bracket with just one hole to drill. It seems remarkably quiet up to now, time will tell!
The fuel pipe between the pump and heater if threaded through the chassis cross member to retain it and shield it from the exhaust heat.

This subject frightens many but fifty years ago I was trained amongst thousands of wires not just four or five so I'm somewhat unperturbed by this.
The heater loom come complete in the kit, all that is required additionally is to be able to connect the 12v feed to your desired source, in my case the leisure battery. This I did with a unique cable from the leisure battery to below the left front seat.
The loom plugs into the heater on a single multi way connection then splits three ways, controller, power feed and pump. In my case the loom was fed through the floor under the right front seat before the split then the control section runs up the right 'B' post and into the roof line to the controller location. The power and pump sections are threaded with existing wiring to below the fuse location under the left front seat where the pump one goes down below the floor through a spare portion of the big rubber grommet out over the Adblue tank and to the fuel pump. The power feed connections are connected to the supplied fuse box all as per the supplied wiring diagrams.

The supplied item is a modern can-bus connected unit with just three wires plus an optional illumination feed. Simple to connect and reasonably simple to use once I'd grasped the meaning of the alternating symbols.
More on the controller and a modification to it later when we have used the heater in anger during four weeks holiday in Europe.
The four weeks holiday in Europe is well under way and unexpectedly the Eberspacher has been needed during the late evening and night time on a few nights. All in all it works just as hoped for and is now fitted with an experimental external temperature sensor.

As mentioned above these heaters now come with an Easystart Select controller which only senses the room temperature at the ingoing end of the heater and has no simple (cheap) way to fit an external temperature sensor. This proves to be problematic in two ways.
  1. The heater heats for a considerable time until the returning air is sensed to be at the required temperature (plus the hysteresis value)
  2. The heater never switches off entirely, it remains spinning to sample the ingoing air.
The solution to this is to fit an external temperature sensor BUT Eberspacher parts suppliers in the UK want in excess of £70 for one of these! There are suppliers on eBay who offer the same item for around £50 or there is a supplier in Czechia selling them for about 40€.
If an external sensor is used the heater switches on and off at the set temperature (plus the hysteresis value) just like a domestic heating system. For anyone who has used an Eberspacher with an 801 controller with the external (but fitted within the 801) sensor connected this is what is achieved with the Easystart Select fitted with a separate sensor.
However I am experimenting with a much simpler component that will do the same job at a fraction of the price, as usual, watch this space!

Maybe I should explain what I mean by the hysteresis value. When the heater switches on at the set temperature it needs to heat to above that value before switching off to allow the heater to cycle through its normal heating procedures. If it were to switch off immediately the set temperature was exceeded it would simply oscillate between on and off in a matter of a few minutes and not be able to run and burn correctly. From experience I have found that this value is about 5 degrees C, i.e. if set at 16 degrees the heater will switch on when the room temperature drops below that setting but not switch off completely until the room temperature at the sensor reaches 20 degrees.
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