Webasto Air Top 2000 Heater Installation

Van Conversion Webasto Air Heater, Final

Webasto Air Top 2000 Heater Installation

The Webasto Air Top 2000 heater, thermal insulation & Maxxair Fan are the key elements to make our DIY camper van conversion comfortable during winter. The van will be used as a winter splitboarding basecamp, therefore heat & humidity control is critical.

The Webasto Air Top 2000 ST/STC is fueled from the main vehicle tank. Fuel consumption is low (0.03 to 0.06 gal/h), electricity consumption is low as well (1.25A to 2.45A on average, more during startup) and there is no humidity added in the van resulting from the combustion as opposed to propane heaters such as the popular Mr. Heater Big Buddy (http://amzn.to/2ggdPq0).



Webasto AND Propex, are both really needed?!

We didn’t add the Propex heater (faroutride.com/propex-install) because we needed more heat (more BTU); we added the Propex because we had some issues with our Webasto and we wanted a SOLID backup plan in case the Webasto fails again. Since then, we took some corrective actions on the Webasto (faroutride.com/webasto-install-new-burner) and our issues are gone; we’re in love with our Webasto again and highly recommend it 🙂



We chose to install the unit under the passenger seat.

Van Conversion Webasto Air Heater, Final

Van Conversion Webasto Air Heater, Final
Final result: Webasto Air Heater installed under the passenger seat



TIME SPENT ON THE JOB: 20-24 hours* (!!)

* Note on the time: The Webasto installation is not rocket science; this is probably doable in 8 hours (some have claim to have done it in about 4 hours). Despite a good planning, the installation process was painful… We do not have a lot of tool and hardware in hand, so we had to make several trips to Home Depot and the Auto Parts store. In addition, we spent at least 4 hours just planning the routing: since we installed our unit under the passenger seat, we had to go across the van exhaust which is a very hot area and it made the routing more challenging. Another contributor to the long hours was the fact that there is not much space under the passenger seat (under the van), so we had to make sure the hole pattern would not fall into a frame. And since the access under the seat is so bad, the installation of the 4 screws, air intake, air exhaust and fuel line was VERY time consuming. That being said, the installation is solid and clean; we’re very satisfied with the final result!





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  • One of the following heater:
    • GASOLINE Webasto Air Top 2000 STC with installation kit and Rheostat Control (Buy from Amazon)
    • DIESEL Webasto Air Top 2000 STC RV with installation kit (Buy from Amazon)
      • Optional (but recommended!) MultiControl HD (Buy from Amazon)
      • This is the “RV” model: It can be switched to high-altitude mode on the MultiControl HD (neat!), comes with silencers and no “special” harness is required to connect the MultiControl HD to it.
    • DIESEL Espar D2 with installation kit (Buy from Amazon)
  • 1x Aluminum sheet 0.062″ thick (to make a flat surface) (free if you get it from a friend)
  • 3x Cross Nut 1/4-20 (optional to avoid drilling new holes in the van structure) (Buy from Amazon)
  • 2x Bolt M8x1.25 30mm length (to use existing tapped hole in the van structure (Buy from Amazon)
  • 1x Ford Gasoline Auxiliary Fuel Port Kit (10$)
  • 3/8″ I.D. Fuel Line 8′-10′ length (check your installation for adequate length) (15$)
  • 5/16″ I.D. Fuel Line 1′ length (connect from Auxiliary Fuel Port to 1/4″ fuel line) (3$)
  • 1x Heat Shield Sleeve 1″ diameter (¾” diameter would probably work) 36″ length (Buy from Amazon)
  • Primer
  • Kleen-Flo RustProof
  • Thinsulate (Buy from Amazon)
  • We learned the Webasto creates a lot of noise! We strongly suggest to also get the material to reduce that noise. Look at THIS POST (Air Heater Noise Reduction) to learn more!
Van Conversion Webasto Air Heater, Material
Well, this is a bit intimidating



  • Drill
    •  2-3/8″ hole saw to cut the hole for the hot air vent
    • 7/8″ hole saw to cut the holes for combustion air intake/exhaust
  • Jigsaw (if you need to fabricate a flat doubler)





*Disclaimer: we’re good, but not that much. Use these instructions at your own risks!


First things first, there are a lot’s of do’s and don’ts so make sure to read the manual that comes with the unit (see “Resources” links above).


1- Fit the Webasto Air Heater unit to the van

The seat was removed.

Van Conversion Swivel, remove front screws

Van Conversion Swivel, rear screws


The jack will be relocated somewhere else. The bolt holding the jack was trimmed flush.

Van Conversion Webasto Air Heater, jack bolt trim flush


We located the Air Heater unit: it must be positioned so it does not interfere with seat base and with the structure under the floor. There is not much room under the van… we used existing fasteners and holes to help us make the correspondence between above/below floor location.

Van Conversion Webasto Air Heater, under the van
Viewing from under the van. Not much room here… (this photo was taken after unit’s holes were drilled)


The surface on which the unit is installed must be perfectly flat for the gasket to work; we had to fabricate an aluminum plate to fulfill this requirement.

Van Conversion Webasto Air Heater, aluminum plate


There are drilling templates provided in the manual, use them! Do not use the rubber gasket as a template, it is not accurate…

(see template in previous picture)


We tripled-checked the location of the unit and proceeded with drilling. Before drilling, we punched the holes center so the drill bit would not slide off center. As usual, we coated the bare surfaces with primer/paint/clearcoat for corrosion protection.

Van Conversion Webasto Air Heater, drilling holes


We then sealed the holes/aluminum doubler with Silicone. This is important to prevent gas fumes from entering inside the van.


The unit is fastened with 4 lock-washers and nuts under the floor. The access is VERY limited, so we had to use a gear wrench:

Gear Wrench
Gear wrench on Amazon. Needs as little as 5 degrees to move fastener VS 30 degrees for standard box end wrenches


After securing the 4 nuts, we applied Silicone under the floor.


2- Route the combustion air-exhaust

We routed it toward the rear of the van near the passenger side tire.


1- We couldn’t avoid a “low-point” in the exhaust routing, so we drilled 3/16″ hole to drain the water formed by condensation (this is per manual. Condensation water trapped in the exhaust will restrict the air flow and the heater will most likely experience carbon buildup in a short period of time). So make sure to add a drain hole wherever there is a low point!

It took less than 48 hours at -5F (-20C) to form these beautiful stalagmites!


2- About silencers: they increase flow restriction in the exhaust and having some issues with carbon buildup in our unit, we decided to remove the silencer.

The exhaust is routed so the gas are dumped OUTSIDE the van edge. This is to avoid carbon monoxide from pooling under the van AND to ensure the exhaust gas does not get sucked back into the intake! We install a silencer at the intake, this will act as a dust filter so that the combustion chamber does not block.


3- Route the combustion air-intake

See picture just above!


4- Route the fuel line and the fuel pump electrical wire

We used 3/8” rubber fuel line to protect the Webasto fuel line and an additional Heat Shield Sleeve (Buy from Amazon) near the van muffler.

The fuel pump electrical wire is routed along with the fuel line.

Van Conversion Webasto Air Heater, fuel line routing

Van Conversion Webasto Air Heater, fuel line shield


We located the fuel pump near the fuel tank (as stated in the manual). The fuel pump was attached using a Cross Nut fitted in an existing hole

Van Conversion Webasto Air Heater, Cross Nut Fuel Pump
Fitting the Cross Nut in the existing hole


Cross Nut: get some, they will be handy throughout the whole conversion (this is what we used to secure the interior cabinets and stuff). The 1\4-20 .280 grip prebulbed type will fit in the existing Transit factory holes found everywhere inside the cargo area. We made a specific post about Cross Nut here (selection chart, how to install & tips).

PlusNut, Pre-Bulbed
1\4-20 .280 grip prebulbed Cross Nut on Amazon.com




Van Conversion Webasto Air Heater, fuel pump


To gain access to the auxiliary fuel port, the tank must be lowered.

We drove the van until about 10 miles to empty (the tank is surprisingly lightweight at this point). Then we put a toolbox under the tank and removed the 6 screws holding the tank. No need to detach the fuel lines (they are flexible). We lowered the tank until we were able to detach the protective fuel cap on the auxiliary fuel port.

Van Conversion Webasto Air Heater, lower the fuel tank
The (emply) fuel tank is fairly light weight


The Ford Fuel Port Kit can be purchased from a Ford Dealer, it’s about 10$.

The fitting was pre-fitted with 5/16” fuel line, then 1/4”, then the Webasto fuel line



Update 2018: 

The arrangement above (5/16″ to 1/4″) could create fuel delivery issues (air bubbles) and the gasoline model is quite sensitive to that (resulting in carbon buildup maybe?). Therefore, we recommend getting a proper fuel line reducer from Webasto:

Molded Hose With Reduction, Webasto Part Number 1319718A


Thanks to Andrew for the tip!


Then we installed the fitting on the tank and connected it to the fuel pump


Van Conversion Webasto Air Heater, fuel pump


Then, we connected the fuel pump electrical wires to the Webasto unit (the wires that are hanging out from the Webasto unit combustion air intake). The fuel pump has no polarity! In other words, there is no positive or negative to follow when connecting the electrical wires.


5- Secure the combustion air-exhaust, combustion air-intake and the fuel line to the unit using the provided clamps

Van Conversion Webasto
Yes, it is possible to attach everything despite the tight space!


6- Route the cabin hot-air duct and install the fitting


Van Conversion Webasto Air Heater, duct fitting hole


7- Install the provided protective screen to the cabin cold-air intake (as stated in the manual)


8- Connect the electrical harness to the air heater unit

Van Conversion Webasto Air Heater, electrical harness connection


EDIT: Before re-installing the seat, we recommend to add Thinsulate (http://amzn.to/2xvx0cY) all around the seat base. We found that it helps reducing the fan noise (don’t expect it to completely go away) and it helps with thermal insulation. If you do, MAKE SURE NOT COVER THE INTAKE OF THE WEBASTO!


9- Connect the Rotary Rheostat (or any Webasto controller) to the harness*

*Different controllers requires different harness! Ensure you have the appropriate one or it will not work…

Webasto MultiController vs Rheostat
Webasto Rotary Rheostat and MultiControl (7 days timer)


10- Connect the harness to the power supply (red wire is positive, brown is negative)


11- Before testing the setup, the van fuel tank must be filled or the air heater fuel pump will only pump air…


12- Turn it on!

The unit requires 3-4 starts for the fuel to get pumped all the way to the unit, so we got 3 faulty starts before it actually worked. Also, when ambient air temperature is above 77F, the unit starts then shutoff immediately for self-protection…


If using the MultiControl 7 Days Timer, the device must be programmed first following these instructions.


That’s it! In your face, winter.


Van Conversion Webasto Air Heater, Final

Van Conversion Webasto Air Heater, Final


STC vs ST model

The following is the result of our own research (with some help). It is not official information, but good luck finding official information…

Availability and technical support:

  • ST: Worldwide
  • STC: Not in North-America… (for now, but it’s coming)

What’s different? Found here:

“This product is the further development of the Webasto Air Top 2000 ST and has the same dimensions and technical characteristics. It also runs under the same legal operating licence as the Webasto Air Top 2000 ST. It uses the standard fuel pump DP42 as used in the Webasto Air Top Evo 40/55 heaters. A change of the applications when using the new heater is not required except for using ta different metering pump ad harness. The Webasto Air Top 2000 STC will ensure full W-Bus compatibility and full operation with the NEW SmartControl and MultiControl without using the Unibox. Can be used in conjunctions with the Webasto ThermoCall TC4, this Can also be purchased on our online shop.”

STC: Features and Benefits

The STC can be controlled with the new MultiControl.




  • On second thought, we would still install the heater ourselves BUT we would buy the ST over the STC to get technical support (until the STC is supported in North-America)…


  • February 1st 2017 update: Our heater had carbon buildup, which caused the malfunction. Carbon buildup after only 200 hours of use is not normal. We had our heater checked by Mellor Online and, after cleaning the carbon, it is supposed to be 100% functional. So there must be something wrong with our installation. Now let’s see what are the possible causes for carbon buildup:
    1. Incomplete combustion caused by Fuel/Oxygen mix ratio too rich (not enough oxygen).
    2. Combustion intake dust ingestion.
    3. Voltage issue.
    4. Dirty fuel.
    5. Fuel pump installed at incorrect angle.
    6. Short run cycles (It is recommended to run the heater for at least 15 minutes before shutting down).

    What’s our plan for each points above?

    1. Re-route exhaust so it dumps the gas outside the van limits, further away. We think that the intake was sucking the exhaust gas back in (therefore there was a lack of oxygen).
    2. Add an intake silencer (acting as dust filter).
    3. Voltage was checked by Mellor Online and is suppose to be fine. Nothing to do here.
    4. Add the Webasto fuel filter just before the pump.
    5. Our pump is installed per manual. Nothing to do here.
    6. We did that already.

    Hopefully this solves the issue.

    We will report back with long term results.


  • October 2017 Update: Carbon buildup issues came back. This time we installed a new burner insert and adjusted the heater for high-altitude. Full write-up here:

Webasto Air Top 2000 – How To Install a New Burner Following Carbon Buildup


  • 2017/2018 Update: No issues! Yay, heater worked just fine all winter! 🙂
  • February 2019: Still running fine, no issues!



Noise. Here are the noise sources we identified:

  1. Fuel pump “ticking” (or “clicking”)
    • Heard mostly outside, but also inside the van
    • irregular frequency, so this is quite disturbing
  2. Exhaust pipe
    • Heard mostly outside the van
  3. Intake pipe
    • Heard mostly outside the van
  4. Fan
    • Heard inside the van
    • Regular noise, does not bother us

Fortunately, there are ways to reduce the noise to a more acceptable level. We cover the modifications in this post here:

Webasto Air Heater Noise Reduction


If using the Webasto / Espar at high altitudes (approx. 5000 feet and more), there are some modifications to perform in order to prevent malfunction or lost of performance. See our post here:

Webasto / Espar: High Altitudes Usage






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Hello! We’re Isabelle and Antoine 🙂 In 2017 we sold our house (and everything in it), quit our engineering careers and moved into our self built campervan. We’ve been on the road since then and every day is an opportunity for a new adventure; we’re chasing our dreams and hopefully it inspires others to do the same!




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107 thoughts on “Webasto Air Top 2000 Heater Installation”

  1. Thanks for the VERY informative site! As far as the Webasto fan noise, I was thinking that perhaps instead of the Thinsulate that you could try the self adhesive sound deadening mat, aka Butyl Automotive Sound Deadener (Noico is one brand).. same as is often recommended for van walls as a 1st layer to deaden noise.

  2. Do you know if the STC model is supported in North America now? I was considering installing the webasto in my ford transit build. However, I’ve only been able to find the STC model readily available online.

  3. Your write up has been super helpful, thank you for posting it. I have a dumb question- the wires for the fuel pump are sticking out of the air intake hole on my heater, and there is a slot in that tube, which makes me think that it’s how it was designed, but I don’t see anything in the manual (or online) to confirm this. Is that how they are supposed to run? Out of the side of that tube?

  4. Hi Antoine,
    To Follow up on my comment on July 18, I was able to get the part from Webasto through a dealer in Missoula and…
    it worked! It is a 90 that goes from the aux port size to the tiny fuel line size. I was skeptical. Second try it worked. No need to drill tank! It was a 23$ part but a huge headache. The part like you made wouldn’t work for me due to the cavitation (my guess) because of the different sizes of hoses getting reduced in size. I will email you a copy of the photo of it and you can post it.
    Thanks again for all the help!

  5. Hi Isabelle and Antoine!
    Super fast question; you mentioned (in some post) that you have been in places with -25C degrees, and I was wondering: for the gas line (if I’m not mistaken, your ST is Diesel, correct?) no issues with the low temperature? I was wondering mainly because I have some issues with the car during winter (-10C) and when I see that little line under the VAN..
    Let me know! 🙂
    PS: I loved your site! will help me a lot to build my VAN! (some day..)

    • Hey!
      We have the gasoline model. I believe gasoline and diesel have additives to prevent freezing in the winter; we had no issue with gas freezing.

      Have a good one!

  6. Your link to the Ford auxiliary fuel port kit doesn’t work. Do you have a part number? Is using the auxiliary fuel port still the best way to do it?

    • Just fixed the link. Thanks for letting me know.
      Using the aux port is the easiest way for sure; I’m guessing using the Webasto fuel port would be better but the tank would have to be drilled.


  7. Are you still running the STC or did you switch to the ST? I think you were running the STC, and that’s why the US technicians couldn’t diagnose the issue? Was your fix to redirect the exhaust to the side away from the intake?

  8. Thanks! Webasto tech help here in the U.S. has their own parts listed for the aux. port connection for Transits. They seem to think that is the problem, since with a gas can I can get the heater to work. Sounds like the gas versions are sensitive to any small air gaps. They list the part numbers but I have to order through a large truck dealer here in town I hope! Luckily, it’s about 90 here and I don’t need it yet but trying to work the kinks out before the winter sets in. I will repost as I get this worked out as your site has been so very helpful. Cheers and if you two end up in Missoula, MT, the riding is fantastic and craft beers are wonderful. We own a house and you are welcome to visit.

    • Thanks for the follow-up. I would really appreciate if you could snap a few pictures of the installation with a short description on how to install the Webasto aux port. I’m guessing you will have to drill to tank? Just curious. Thanks! 🙂

  9. Hi there. I’ve used nearly the exact same parts as you have but I cannot get fuel to ignite the heater. I’ve dropped the tank again to re-check and tighten fittings and still no fuel to the output side of the heater. Is there any way to help prime the lines? Your site has been awesome and so helpful!

    • It takes 3 or 4 consecutive starts to prime the line. Reset the error code and try again 3 or 4 times.
      If it doesn’t work, I suggest to disconnect the fuel line from the pump (on the side of the heater, not the gas tank) and attempt to start; is there fuel pumping? Yes? Then disconnect the fuel line from the heater and attempt to start; is there fuel coming out of the line? If yes, the problem is probably from the ignition…

      Hope that helps!

  10. For the connection fitting, did you run the fuel line all the way through until the bottom of the tank? Or is the ford aux connection point enough, and you do not need to run a fuel iine into the tank?

    • We used the Ford aux port; the factory straw runs until about the 1/3 of the tank. In other words, if your tank is below 1/3 full your webasto will suck air. But that’s fine with us.


      • Oh wow thats useful to know. I just did the same thing with the aux port, it was such a pain to get off! The button you need to press is wedged between this plastic bar so you cant use pliers.

        It was such a long process to install, but your guide helped so much! Thanks again for your help.

      • One more thing, since it will be spring time soon, and there is no need for a heater, how often do I need to run it to ensure that it doesn’t break for 8 months of non usage? I figured since you guys have had it for about a year now you would know.

  11. Hey Antoine,
    How did you manage to secure the aluminum template to the floor? Even after you do that, due to the divets and the valleys in the metal, there will still be gaps. Did you use silicone to cover that V shaped valley?

    Also why do you say the plastic seal template is no good? I lined it up to the bottom of my unit and it looks like it matches. But using the paper template could work too, its just that I dont want to make mistakes with the measurements

    • If I recall correctly, the aluminum template is sandwiched between the heater and the floor (the template is not secured itself). There is a gap between the floor and the template; I used some silicone but I didn’t totally filled the V.

      You will get better results using the paper template; as opposed to the rubber gasket, it’s not elastic so it’s more accurate.

      Good luck!

      • Thank you, makes sense! The hardest part for me so far has been drilling the holes into the van. Ford makes some sturdy cars lol

  12. Thanks. What size barb is it from the 1/4 to webasto line? Did u use barbs on the connections from the pump to the webasto line?

    • Hang on, I didn’t get you right. I meant to say we used Fuel Hose Clamps, not barb. You just push the webasto fuel line into the 1/4 fuel hose and then put a hose clamp.

      Sorry for the confusion.


  13. Antoine..in your picture with the ford fuel connection do you have a barb from the 5/16 hose to the 1/4 hose then another barb from the 1/4 to the Webasto hose or are the hoses just pushed inside each other?

    • There is a barb at each connection; if not, fuel could leak or/and air bubbles make their way into the fuel line:
      No barb, just fuel hose clamps at each connection:
      fuel line webasto

  14. Yeah I’ve seen that switch but I am actually talking about a setting to enable it in the multicontrol controller. If you go into settings on the multi control there is an option called altitude correction. You can simply turn it on and off via the mult control.

    I should get by webasto stc in a few weeks so I hope this setting is enabled in my controller.

  15. Did your multi control have an option for altitude correction? I was looking at the multi control manual below and it has an setting option to turn on altitude correction on page 21. I ordered a STC with multi control and am crossing my fingers mine is enabled.


    • It’s possible to order a stand-alone switch for altitude mode, so I inquired about that. I was told the only model that is compatible with that switch is the DIESEL “RV” model… so i’m guessing that unless you ordered that model, the altitude mode won’t work; but please prove me wrong 🙂

      Let us know!

  16. I’m having never-ending battles with what seem like the most basic tasks…. How did you attach the resilient and un-compressable intake and exhaust tubes to the underside of the heater unit? I’ve tried hose clamps. Those blow out before there’s remotely enough pressure to hold the pipe in place.

    • We attached them with … hose clamp. I’m pretty sure the clamps were included in the installation kit. If I remember correctly, they looked more heavy-duty than regular clamps. Maybe an Auto Part Shop would have them?

      Good luck!

  17. This has been quite the adventure.
    I have the heater installed, and spliced the electrical wires to extend them so they were long enough to reach the fuel pump. I’m still not able to get the unit to start though.

    If I disconnect the fuel hose between the pump and the burner I don’t see visible dripping, but I do get diesel on my finger if I touch the nozzle (so there is a small amount of fuel going through from tank to pump). I haven’t had any success getting the burner to start yet though.

    • You should definitely see drips of diesel.
      Have you try 3-5 times to start it? It takes a few consecutive attempts to prime the line.
      Also, sorry to ask, are you sure your fuel tank is above 1/3 full? If not, the pump will suck air not fuel…

      Good luck.

      • Yeah, the tank is completely full. I wish it was something that simple.
        Today I took a sipon bulb and tried to pre prime the line.

        Through process of elimination I worked back to where the fuel line inserts into the tank. I.e. I’m not getting gas when I try to prime it from there fuel line between there and the pump.. looks like I’ll need to drop the tank again and investigate.

  18. I have the diesel version (of both the heater and the van) and am attempting to replicate your installation here.

    The electrical wires for the fuel pump are significantly shorter than the fuel lines though (only 2-3 feet) so I don’t imagine I’ll be able to place the fuel pump close to the tank and connect it to them.

    Am I missing something?
    I’m considering splicing and extending them as well.

    • Do you mean the electrical wires are 2-3 feet shorter, or 2-3 feet total length?

      If I recall correctly, we did not have to splice the wires they were long enough… but I’m pretty sure it can be done if needed.

      Good luck,

      • The wires are 2 to 3 feet total length. They have the special connector on the end, so I’ll need to cut them and splice them.

  19. I have a gas promaster and looking to to add a heater. Sounds like you and many others have had piles of problems with the gas version of the webasto. Would you buy it again? Think espar is better?

    • The jury’s not out yet. We replaced our combustion chamber and time will tell if the issues comes back or not. If the issues come back, I would not buy it again! I would probably install a diesel model with a small aux. diesel tank…
      I don’t know if the Espar is better than the Webasto, sorry I looked around but didn’t find any feedback.

      Good day,

  20. Awesome that you guys keep all this info updated! I did eventually find the fuel pump in their schematic. I missed it at first because they provide more detail than most would care about.

    Anyways, almost finished he install last night after 2 days of work. Cold and rainy. Should have done this a month ago!

    Two last questions if you have a minute. 1) How did you mount the intake silencer? The plastic clip it came with seems pretty useless. 2) How far back did you run the exhaust line on rev2? I have 2x 1m lines and the muffler in the middle. Not sure I want to make it any longer but it’s right at the back end of the door which I’m not overly happy about.

    • 1) Yeah, we used the plastic clip but it fell off. We wanted to fixed it somehow, but it’s been hanging from the unit for like 2 months (we have a leech so we don’t loose it). Sorry we’re not much help here 🙂

      2) We have 2 meters exhaust length, so the exhaust end dump outside the van “edge” just in front of the rear wheel. It’s at the back end of the sliding door, but when the heater runs, it’s because it’s cold outside so the door stay closed!

      3) Do you have the gasoline model? I would not suggest adding an exhaust muffler (too much air restriction), but maybe we were just unlucky (i’m referring to this: https://faroutride.com/webasto-install-new-burner). Let us know if it works in the long run!

      Good day!

      • I ended up finding an extended clamp that worked really well for the intake mount. I have some pics and part numbers if you want I can email them to you. You’re welcome to try it and/or post info here.

        That’s where the good news ends though. Fired the heater up this weekend and got repeated F94 faults. That’s a temp sensor failure. Seems strange. I also don’t hear the fuel pump click at all. Not sure what the root cause is. Fuel pump problem causing no heat and temp failure. Or temp sensor problem not letting the fuel pump turn on. Planning to call wevasto shortly.

        One quick question I’m unsure about. Did you have to add a hose to the Ford aux to the inside the tank. I assumed there must be a channel to the top port that it draws from and it’s jus that small adapter but I can’t find much info about it.


          • Problem fixed. Heater is running great!

            Luckily, it turned out to be something quite simple. I didn’t insert the wiring harness fully into the heater. Turns out, it is a really tight fit and needs to be inserted until it clicks.

            I think the error came about simply because one (or both) of the temp sensor pins weren’t making good contact.

            I got the F94 code on my MultiControl unit.

            I’ll let you know how things go long-term. Fingers crossed for no Carbon buildup!

  21. Hey, going through the install right now and can’t find any information on the fuel pump wiring. Do you recall if the fuel pump has any polarity?

  22. Hey Antoine, I just ordered the same Webasto heater for my Transit this weekend and I’m trying to prep for the work and make sure I have the right supplies. You mentioned this regarding the fuel line:

    “The fitting was pre-fitted with 5/16” fuel line, then 1/4”, then the Webasto fuel line.”

    How did you connect the different fuel lines together? Is there some sort of fuel line reducing coupling or hose adapter that I need to buy? Thanks!

    • They will fit one into the other, interference-fit. Then use FUEL-CLAMP to tighten them (you can buy them from Auto part shop. don’t use worm-clamp as it will let air inside the line). Refer to the picture above with the aux fuel tank port. Good luck!!

      • Okay thanks. It sounds like I’ll just need to see the parts in person. I feel there may be many trips to the auto parts store in my future like you guys. 🙂

  23. Thank you. I was told by a Webasto dealer in the UK that the “wire to ground, etc.” procedure does not do anything unless the unit has the optional “RV ECU”. And the RV ECU is only available with diesel heaters, not our petrol/gas. I’m in the same predicament as you – I sure hope Webasto come out with a fix for the petrol heaters.
    BTW I extended out my (silencer-less) exhaust to 3 meters so as to minimize exhaust air being sucked into the intake. It terminates just in front of the right, rear wheel and is angled out and away from the vehicle underside. I am also going to lag the exhaust to try and minimize cooling of the exhaust gases.

    • Wow, is anyone is having luck with the Petrol heater??
      I don’t think webasto agree that there is an issue with their petrol heater…

      According to TechWebasto, the procedure should work with the petrol too, but who knows.

      Let’s keep in touch,

  24. Antoine, how did you adjust the STC for high altitude? Did you connect the wire to ground, etc., as discussed in https://faroutride.com/webasto-espar-high-altitudes/ and does this procedure work for the 2000STC (I have the rheostat)? My supplier in the UK (and Webasto UK) did not seem to know anything about this procedure and said it would not work with UK heaters. I purchased my heater from the UK. Thank you.

  25. We also inatalled the stc model and have had multiple issues. We were told that its carbon buildup on the filter plate and that his unit does nkt function properly at elevation (they are assembled at sea level we were told). All in all itis not reliable and we are thinking of eventually replacing it with a diesel version which is supposed to be much better.

    • Yeah, I just opened the unit and there was indeed hard carbon on the combustion chamber; I installed a new chamber and adjusted the unit for high-altitude. We used the heater for 10-20 hours since then so it’s too soon to draw any conclusion. But it’s working great so far! We’ll see!

  26. What’s up,I log on to your blog named “Webasto Air Heater Installation | FarOutRide” daily.Your story-telling style is awesome, keep doing what you’re doing! And you can look our website about اغانى 2018.

  27. Well.. I was just reviewing your install before installing our STC unit that arrived. I guess I should have looked again before ordering the STC and stayed with the ST unit. Oh well..

  28. Hey Antoine. Thanks for the overall build writeups and website, great stuff!

    The webasto seems like one of the more complicated installs of the whole build, and not an inexpensive component either. I was wondering just how warm it keeps the van when in use? I saw in your insulation article that you tested the insulation on a 37 degree night with the heater running and kept the van at 55 degrees. Was that by choice, with the heater running on low? Or was it maxed out? Just curious if it can keep the van at more regular temps (around 70), and if so, how hard is it working to do that?


    • Hi Andrew!
      We keep the van at around 55F at night just because we think it’s fine, not because the Webasto is maxed out.
      The Webasto is able to maintain 70F inside the van when it’s -15F outside. This is the “worst” case we encountered. In that case, the Webasto was running on high constantly. If it’s around 32F outside, the Webasto runs on LOW.
      Raising the temps is a different story (from let’s say 15F to 70F); we will sometime use the van engine as a boost to shorten the time required.

      Obviously, your insulation will have a big impact on that.

      To make a long story short, we feel the Webasto Air Top 2000 is sufficient. I believe some people have installed the Webasto EVO unit (more BTU).

      Thanks for stopping by!

  29. Great build, you need to keep the exhaust hose shorter than 6ft any added angles to the hose, 90 degree bend will reduce hose length by a foot. The silencer would also create back pressure creating carbon build up. Run unit twice a month throughout the year for at least 15min.

  30. Ordered an STC through ButlerTecnick before seeing your comments. I can’t find anywhere the difference between ST and STC. Is it just in the lack of North American technical support? Haven’t installed it yet, but am mapping everything out and wondering if it is a deal-breaker. Can you elaborate on your findings/recommendations? Incredibly helpful site BTW- you all are doing it beautifully.

    • Hey,
      The STC seems to be the “evolution” of the ST model. Same physical parts except for the fuel pump, control unit and harness. We were told the STC uses different running parameters. With the release of the STC, they also introduced the new MultiControl (the one we use). Our guess is that it is not available (or supported) yet in North America, but hopefully it will be eventually. Until the STC is supported here, we would buy the ST over the STC.
      Check these out:
      STC features and benefits
      STC vs ST

  31. Hello! Just discovered your awesome site!!
    We are doing a Promaster build, wondered how to heat it, then found your page.
    We love the ideal of the gasoline burning Webasto, especially with under passenger seat placement.
    Bottom line, would you use Webasto again?
    I noticed you had an ST vs STC issue in N.America.
    Thanks again for all the time and effort you’ve put into this site, it really really helps.

    • Hi Rober,
      we are still waiting for the Webasto diagnostic, but they are normally suppose to be reliable. We would use it again, but we would definitely buy the ST over the STC just to get technical support in North America.
      Glad you like the site 🙂

  32. Thanks you two for the blog post. I just installed mine and I don’t know how long it would have taken me to figure out without your advice. Some tips I discovered along the way and some comments:

    – I mounted the heater in the same location and routed the lines the same way as they did. The fuel line routing seemed perfect but the exhaust leaks directly into the van when I open the sliding door. There is a light smell even with the door closed, and I’m not sure if this is normal or maybe some exhaust is seeping through the seems of the slider. I’m going to either extend the exhaust pipe or route it to the left side of the van.

    – The position of the heater unit (if under the passenger seat) needs to be very precise. There’s only a small area you can access easily from underneath, and the position shown is it. I made the mistake of mounting it slightly too close to the passenger door, and when I went to lower it in one side hit the frame of the seat. I had to re-drill.

    – The jack I was able to mount left of the heater. I used one of the existing bolts directly, and was able to wedge the jack holder in between the seat frame and directly up against another one of the bolts. I just used a nut and washer on the second bolt to indirectly hold down the other side. It just happened to fit perfectly. See a photo here: http://imgur.com/a/4jet8

    – On starting the heater for the first time, I had to restart over 10 times to get hot air to blow. It blew only cold at first. I did here the fuel pump click so that was a good sign. Had me pretty worried, but working well now.

    Hope these tips further help future installs!

    And thanks again!

    • Thanks for the tips!
      We will eventually put the jack back under the passenger seat; we’ve been procrastinating… thanks for sharing your install.

      We don’t get any exhaust smell when all doors are closed. Feel free to share where you re-routed yours. Do you have a silencer? Exhaust length is restricted to only 2m with a silencer 🙁

      Enjoy the heat!

      • Curious as to why your restricted to 2m with the use of the silencer? Can you not add another length of exhaust to the exhaust-port of the silencer hence an overall further distance from the (potential) door situation?

        • The Webasto manual state that the exhaust length is restricted to 5 meters without silencer or 2 meters with silencer. Adding pipe length increase the pressure drop; those heater are sensitive to it. It could affect the combustion. That’s why I installed my exhaust near the sliding door. I always try to follow the manufacturer recommendations…

  33. What did you do to reduce the noise? I’m thinking some plywood lining around, under the seat and some insulation as well. Thoughts?

    • Oh, I see that we’ve been procrastinating with the Noise Reduction Post… here is a spoiler!

      – Fuel pump (outside but mostly inside the van): we inserted a closed-cell foam between the P-clamp holding the pump and between the van structure. We followed these recommendations as well: (click here).
      – Exhaust (outside the van): we installed this silencer: (click here)
      – Intake (outside the van): there is also a silencer available, but we missed it when we did our order… (click here)
      – Fan (inside the van): we did nothing so far, because the fan makes a constant noise and we don’t really care about that.

      Does it make a difference? Yes, but not THAT much. We think it is worth doing the modifications above as it helped to reduce the noise, but don’t expect to completely suppress the noise!

      Maybe someone out there has better solution?

  34. “New 2016 Harness and Fuel Pump” for Webasto Air Top 2016. Question: I got a Webasto Air Top 2000 ST (second hand) fitted into my campervan a couple of years ago. It worked ok in the beginning, but the postioning of the heater hot air blow pipe made the floor vinyl hot and smell of burning. So I moved heater flexible pipe exit away from that area. But the heater still had an odour similar to something that had burnt out (or was about to burn out). It was not an overwhelming odour but you would know the heater was turned on. So I have bought a replacement for this old Webasto Air Top 2000 ST, one which was advertised on ebay recently for just over £400 (heater only). This heater is the “2016 STC” that has apparently replaced the “ST”. I have only bought the heater unit alone and was hoping to switch it with my existing system(harness,fuel pump,basic controller ect) that cost me quite a lot for parts & to get fitted originally. Will it work ok ?

    • Hi Andy,

      I’m afraid this question is beyond my knowledge 🙁

      What I do know is, the Webasto products line is difficult to understand! There are many variations of the products and we could not find clear information about them. This is one of the reason we bought a complete installation KIT; to ensure everything would fit together!

      I suggest you to write to competent distributors/technicians such as Mellor Online or ButlerTechnik to find out. And send them pictures of your hardware with part numbers.

      Good luck!

      P.S. Could the smell comes from the exhaust fumes? I heard some people had to relocate their exhaust so the fumes do not exit directly under the van. And I would definitely install a CO detector (it it is not already installed), you never know!

  35. Well, I got it installed! 20 hours, would have been at least double without these instructions to follow, thanks so much. I used 10ft of the 5/16 fuel-line to protect the skinny Webasto fuel-line. 3/4 heat shield worked just fine (as you suspected). Used 1/8 aluminum as the backing plate and a piece 7″x4″ was big enough to completely cover the indentation (rib) in the van floor, making sealing it easier. Used dicor lap sealant around the perimeter. Jack was relocated a couple of inches towards driver’s seat using 2 more riv-nuts and i can still remove it through the large center hole in the seat swivel plate. Supplied harness does not work with Multi-control, just as you warned, thanks again.

      • Thanks. Mine is for 4-season camping also (Road/MT Biking, Kitesurfing, Backcountry-Skiing). I’ve completed: Maxxair, Thinsulate, 3″ insulated floor sandwich, 305w MPPT solar, 90% of electrics (200Ah Lithium, 2/0 cabling), 8020 framing (incl. slide-out 2-bike 8020 tray under bed), non-pressurized plumbing system (incl. internal gray-water tank, solenoid discharge valve), 7g electric hot water with centrifugal pump, digital thermostat and tank-level sensor (12v/700w, used as solar dump-load), ARB on slide-out under platform bed, 3rd (removable, Transit) seat canter-levered over rear of sliding door step (this took forever to engineer), swivel seat, and the Webasto. Currently working on a one-piece stainless shower pan and enclosure (behind drivers seat), replacing temporary wood panels with finish wood panels and a dining table between 2nd and 3rd seats. This sure has been a lot of work, but very satisfying.

  36. That heater looks like a great solution. The fact that it uses on board fuel is a big plus. My question is how are these heaters as it relates to trouble free operation, what parts are likely to fail and how expensive are replacement part? Are they DIY serviceable?

    Thanks, this is an inspiration!

    • Hey Martin,

      These heaters are pretty common in transport trucks i believe, so i would expect replacement parts to be available from local dealership (there are 2 or 3 in my city) or online (https://www.butlertechnik.com/, heatso.com, etc). I’ve seen a few DIY on youtube; it seems to be serviceable, but i have not look much into it since our unit is new and it should run trouble-free for a while. Hopefully!

      I’m afraid i cannot really answer your questions for now, in a few years we will be able to tell!


  37. One more quick question: did you install the fuel filter before the pump? Did not see it in any picture. And, finally, is there anything you would do differently if you were doing it again? Thank you

    • The Webasto installation manual states that the fuel filter is not necessary if using “clean” fuel; so we did not install the fuel filter.
      We now have spent 5-6 night at around 32F outside temperature and the Webasto keeps us nice and warm, we’re happy with the installation!

  38. Hi, thanks for great write-up. Will be installing mine next week. Just curious about the large cabin-hot-air outlet duct: why did you make it S-shaped and have the outlet on LHS rear of seat, rather than just going straight back to RHS of seat (hence a much shorter run)? Thanks again,

  39. Not relevant to the heater, but:
    1) 3.73 or 4.11 rear? and;
    2) do you wish you had the other gearset?
    3 got limited slip differential?
    3) could you have gotten a dual-slider? and;
    4) any benefit you see?
    5) happy with the heater? Noise under seat vs. boxed?
    6) you guys from the NE? Couldn’t find if you stated.
    7) to be continued…
    Hack Saw

    • 1) 4.11 (no other option with the Extended Length)
      2) Can’t compare, so I cannot answer that. We’re getting 16 MPEG on average.
      3) Yes. Did not try in snow yet.
      3) not sure about that.
      4) no, we would loose usable space inside (for cabinets and overhead storage).
      5) Yes! There is some noise inside from the fan, but it’s regular so we get use to it. There is also noise from the fuel pump (pulsations) which is annoying. Outside, it is quite noisy so we just installed a silencer and it helped.
      6) Close enough! We’re just north of Montreal in Quebec. But we spend most of our vacation in NE (New-England, right?) for BEER & BIKE 🙂

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