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 (learn more: Condensation and Moisture Control in a Van).

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 (Buy on Amazon).



Webasto AND Propex, are both really needed?!

If you look through our Build Journal, you’ll noticed that we have both a Webasto heater AND a Propex heater… 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 in 2016/2017 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 ūüôā The Webasto has been running fine since 2017!


Multicontrol HD: Only one active timer limitation

Yes, it is possible to create multiple timers (automatically turn ON/OFF the heater at a desired time) with the standard Multicontrol HD (the one included in the kits), BUT ONLY ONE timer can be active (the others won’t be enabled)… In other words, the standard Multicontrol HD has only one usable timer really, no more. Why? This has to do with legal requirements (for passenger vehicles); we forgot the exact details. That is quite annoying, but there is a workaround: you can get this one and all 21 timers can be active (enabled): amzn.to/3dEs4Ev. We upgraded in our van (no need to change the wiring harness or anything) and we confirm all timers can be active. It would be nice if the kit came with this one, but it is what it is…



We chose to install the Webasto 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!




DISCLOSURE: This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc), we will receive a commission fee. The price you pay remains the same, affiliate link or not.





  • One of the following heater:
    • GASOLINE Webasto Air Top 2000 STC with installation kit and MultiControl HD (7 Day Timer) (Buy on Amazon)
    • DIESEL Webasto Air Top 2000 STC RV with installation kit (Buy on Amazon)
      • Optional (but recommended!) MultiControl HD (Buy on Amazon)
      • The diesel model listed above 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 on Amazon)
  • Additional exhaust pipe, 22mm inner diameter (Buy on Amazon)
    • Most kit comes with only 0.5m length exhaust pipe. Warning: it is recommended not to exceed 2 meters of intake+exhaust pipe, as adding more length increases air restriction and this might create carbon buildup issues.
  • 1x Aluminum sheet 0.062″ thick, to make a flat surface (edit: some kits include a mounting plate).
  • 3x Cross Nut 1/4-20 (optional to avoid drilling new holes in the van structure) (Buy on Amazon)
  • 2x Bolt M8x1.25 30mm length (to use existing tapped hole in the van structure (Buy on 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 (¬ĺ” diameter would probably work) 36″ length (Buy on Amazon)
  • Primer
  • Kleen-Flo RustProof
  • Thinsulate (Buy on 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. Please note that the kits we listed in the material section above now come with a flat mounting plate (amzn.to/37bt3Hz); no need to fabricate it!

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 after having some issues with carbon buildup in ours, we decided to remove the silencer (but we kept the intake 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 installed 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!


WARNING: It is recommended not to exceed 2 meters of intake + exhaust length (total), because adding length increases flow restriction (eventually leading to carbon buildup issues).


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 on 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 (Buy on Amazon) 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 ‚Äď How To Install a New Burner Following Carbon Buildup


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



Noise. Here are the noise sources we identified:

  1. Fuel pump ‚Äúticking‚ÄĚ (or ‚Äúclicking‚ÄĚ)
    • 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‚Äôre Isabelle and Antoine ūüôā In 2017 we sold our house (and everything in it), quit our engineering careers and moved into our self built campervan. We‚Äôve been on the road since then and every day is an opportunity for a new adventure; we‚Äôre chasing our dreams and hopefully it inspires others to do the same!




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139 thoughts on “Webasto Air Top 2000 Heater Installation”

  1. Hi Antoine I’m installing Webasto 2ooo in my 2020 Ford transit and I would like to know where to get the hose from ford fuel port kit to webasto fuel line part # 1319718A having a hard time finding dealer. Any information would by great thanks. Clay

  2. Great blog! Silly question. The power connection for the fuel pump comes out THROUGH the combustion air intake port. How in the world do you route this wire through air filter? Thanks.

    • There is a “crack” in the metal portion of the air intake; the wire must be routed through this. In other words, the wire is NOT routed through the air intake flexible hose.

      Hope that makes sense!

  3. Antoine, I promise this is my last question for the heater. Thank you so much for your write up. My install went flawless. The only issue I have now is my 7 day multi control timer doesn’t appear to be working. Based on your notes, it would appear I need a new wiring harness. The Rheostat works perfect. Can you point me to the wiring harness that is needed?

  4. Thank you for your amazing website and information. I am trying to stay away from propane in van conversion(for water heater) and am considering the rixen system. Certainly pricey but would allow all gasoline for furnace and hot water. Have you had any exposure to this system yet in your travels? Have you heard of any major issues with the system? TIA

    • I’m lurking on their website, but it’s not clear what the product is… Are they just a re-seller/installer for Espar Hydronic System? I’m familiar with the Espar products, but any more info on Rixen products would be appreciated. Thanks.

      • From what I have gathered they are the first commercial product to use a heat exchanger to allow one system to power both water heater and furnace. From the espar furnace, it heats a liquid(?propylene glycol?) which circulates into the van through hot water heater. If wanted can tap into hydronic system of engine to heat water while driving or add on shore power if desired to heat water. The other benefit of using rixen is the customer support. From what Jim Rixen says, he is willing to be available for installation questions and fix product issues(one forum poster sent in faulty espar and had one day turn around). It comes at a hefty price, at least $4000 for entire system. I think Winnebago Revel is using this system. I like the idea of using one fuel for everything and have not seen anything else on the market similar to this. Youtuber humble road seems to be using a similar system in his new build but I think he is DIYing it. This pdf I found on their website has more technical info if you want to check it out. https://static1.squarespace.com/static/5b919721ee1759aa80ba33b1/t/5bb02d0508522984f2d4e366/1538272523779/MCS16v3-Installation-Manual.pdf


  5. Hey with only the rheostat controller do you or anybody know if there is a way to change between recirculation and fresh air mode? Or is it automatic? Thanks

    • Only heat-mode is available with the rheostat; no ventilation mode.
      And note that “ventilation-mode” isn’t fresh air; it’s air from inside the van (so recirculation). It’s the same with Webasto/Espar/Propex/etc.


  6. Hey Guys,

    I have me heater installed and everything is working just fine. Your carbon build-up issues have me concerned for good reason! Do you turn the heater on and just leave it set to ~55F, which would have the heater running in the ‘Low’ mode at somepoint? OR do manually turn it on and run it full blast for periods of time to minimize carbon buildup?

    I was hoping that the ‘Smart Controller’ would allow me to set a bunch of Timers throughout the day and then forget about it running the unit on HIGH for short bursts throughout the day. BUT to my anger, you can only have one timer active at a time (even though you can ‘program’ a bunch of timers), which requires you to activate the next one, defeating the purpose of the timers altogether?

    • Yeah unfortunately you can’t set multiple programs ūüôĀ

      We turn the heater off at night for a few hours (depending on how cold it is outside) and during the day when we’re out; therefore when we start it again, it has to run on “high” to catch up.
      I think it’s OK to let it run on “low” for a few hours, then “boost” it for 10 minutes or so before turning it off.

      It has work for us.

      Have a good one!

  7. Hi Antoine,

    Trying to think ahead for the heater (we won’t do it until fall), but how did you route the power and the thermostat? Did I seen the thermostat back in the middle of the van?? Seems you could come under the floor between the two sets or come down the passenger seat belt column.

    • It’s routed underneath the cabin carpet (there’s a small gap under the passenger seat base, wires can actually run through this). Power and thermostat are then routed in the driver-side wall up to our electrical cabinet (power) and up the wall near the bed (thermostat) (I recall we had to buy an extension https://amzn.to/2Y11KPN).

      Hope that helps!

      • Thanks Antoine.

        Hey, your new electrical write up is great!

        We leave for our first van trip in 2 weeks, 3 weeks from MI to CO,CA, OR, WA, and MT and back, and still, so undone. Quite now, we will be using the stock battery as we only need to power the lights, some power plugs and the lights.

        I will try to get you some pictures via email but it might not be until we are moving and I have time.

  8. Was wondering if you kept running the unit once per month during the non winter months?

    I was talking to a rep and he told me to run my unit 10 minutes per month in order to prevent buildup of materials in the tubes. Did you guys have to do that or was it run and done all the way until next winter?

  9. Still spring here and then summer comes, no need to heat yet, so this is a long way off.

    But. Did you ever consider using a separate tank for the Webasto? Next Q: how much gasoline does the Webasto use per month in the winter? A gallon or two? Or 10?

    Basically, not excited about moving my tank about to install and then always have to remember to keep it half full for the Webasto to work.


    • We can’t really measure the actual consumption, but I would describe it as “negligible”. From specs: 0.03 to 0.06 gal/h

      I think the main advantage of the Webasto is the fact that you don’t have a separate source of fuel… it’s easier to keep the tank above 1/3 than having to fill a separate tank in our opinion. But I guess it’s a personal thing.


  10. Received my Webasto STC Gas kit today, and sure enough it included a steel plate with the holes cut out! Super simple to install.

  11. 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.

  12. 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.

  13. 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?


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