We’ve been using our gasoline Webasto heater (Air Top 2000 STC) since 2017. It plays a CRITICAL role in our full-time Winter Vanlife snow-chasing adventures (faroutride.com/winter-vanlife) and has kept the van warm in temperatures as low as -31Ā°C (-23F). This article contains everything you need to know to build your knowledge (1- Theory), install the heater in your vanĀ (2- Installation), and get a real-world feedbackĀ (3- Review). Even if you choose a different brand (Espar instead of Webasto), different fuel (diesel instead of gasoline), or different van (Sprinter, ProMaster instead of the Transit), this should get you going. Follow the guide!
Table Of Content
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.
1- Theory
1.1- In a nutshell
Gasoline/diesel space heaters generate heat by fuel combustion. The fuel is typically sourced from the vehicle’s main tank, which is very convenient since there is no need to monitor and refill an auxiliary tank. So long as you have gas in the tank, you’ll never run out of heat. Nice! That being said, they also require a little bit of electrical energy to power the fuel pump, the “glow plug” (to ignite fuel during startup), the fan, and the controller. Here is the fuel and electrical power consumption for the Webasto Air Top 2000 STC (7,000 BTU/2 kW):
Fuel Consumption
- Low: 0.03 gal/h (0.11 L/h)
- Medium: 0.045 gal/h (0.17 L/h)
- High: 0.06 gal/h (0.22 L/h)
Current Draw
- Low: 1.25A
- Medium: 1.7A
- High: 2.45A
- Startup (under 2 minutes): 7.5A
When looking at the numbers above, keep in mind that the heater doesn't run all day. In cool temperatures (5Ā°C | 40F), you might only need to run it an hour or two in the morning/evening. The colder it gets, the longer it has to run during the day.
Note that you cannot choose between low/medium/high settings; you select the room temperature, and the heater automatically toggles between off/low/med/high to reach or maintain the selected temperature. It’s a bit like a cruise controls on a vehicle: you select the desired speed and the vehicle control how hard the engine works.
One of the major benefits of the Webasto/Espar heaters is that they generate dry heatĀ because they are vented heaters.
Vented Heater
In a vented heater, the air used for the combustion (outside air) is completely isolated from the air used to heat the cabin (inside air). The heat is transferred from one to another via a heat exchanger. As a result:
- Heating greatly lowers the relative humidity (RH) in the van.
- There is no risk for carbon monoxide poisoning.
Non-Vented Heater
In a non-vented heater, the air used for the combustion is the same air used to heat the cabin. As a result:
- Heating greatly increases the relative humidity (RH) in the van (water vapor is a product of propane combustion!).
- There is a high risk for carbon monoxide poisoning (a window or fan MUST be opened to vent the carbon monoxide)
Dry heat is a BIG DEAL because it helps prevent mold issues, which could ruin your van and your health. We have a LOT to say about moisture and condensation management, but that’s out-of-scope of this current article… we highly recommend reading this later though:
1.2- Choosing the right heater size (BTU)
Both Webasto and Espar offer a 7,000 BTU (2 kW) model or a 13,650 BTU (4 kW) model.
While you might naturally want to go for more BTU (more heat is better, right?), there is a catch: a more powerful heater will run on “LOW” much more often. And when they run on “LOW” for extended periods of time, this type of heater (Webasto/Espar/Planar/Unbranded Amazon Knockoffs/etc.) tend to develop carbon buildup issues (very hard soot deposit) in the combustion chamber and that phenomenon gets worse as you go up in altitude. Too much carbon buildup and the heater will stop working.Ā That being said, you can operate your heater for years without carbon buildup issues by choosing the right size, by following installation requirements, and by operating the heater correctly. To learn more about the issues we had with carbon buildup and how we successfully “fixed it”, scroll down to section: “Carbon Buildup/Sooting Issues“.
We won’t lie, it is difficult to come up with specific guidelines for choosing the right heater size as it involves many variables:
Insulation Type
The heater must compensate for the heat loss. The more a van allows heat loss (poor insulation), the more the heater has to work.
Carbon Buildup Prevention
Oversizing your heater might sound like a good idea to make sure you get enough heat; unfortunately, this can lead to carbon buildup issues. This variable alone makes our choice much more complicated because getting the right size heater is critical.
Insulated Window Covers
Windows are a MAJOR contributor to heat loss. Having proper insulated window covers is essential for winter vanlife; they minimize heat loss but also make the living area more comfortable (otherwise it's very cold near the windows).
Location
We spent some time in the Arizona desert in winter, and, yes, it gets quite cold at night. We used our heater in the mornings and evenings. On the other hand, we spent an entire winter in Canada (and near the border of Alaska), and that is on a whole different level. It is not unusual to have -30Ā°C (-22F) for days or weeks, day or night. Having a reliable source of heat is critical for safety when it's that cold!
Interior Layout
A van with a "garage" setup like ours requires less BTU, because the garage is not heated as much. And with our living space being in front of the van, having the Webasto installed under the passenger seat is ideal for us. In addition, heat rises, so our "elevated" bedroom area is always nice and warm. On the other hand, installing the heater under the passenger seat might not be ideal for a layout where the living space is in the back.
The combination of all the variables above makes it hard to provide clear guidelines… That being said, after spending two winters full-time in our van in the USA and Canada, here is our opinion on which size heater to get:
7,000 BTU
(2 kW)
Best all-around solution for winter vanlife down to 10F (-12Ā°C). It'll still be enough to maintain your van warm in colder temperatures, but it'll take longer to warm up a completely frozen van (left alone without heating for a long time). That's what we have in our van and it kept us nice, and warm in temperatures as cold as -22F (-31Ā°C) during two full time winter vanlife adventures.
13,650 BTU
(4 kW)
It is worth considering for a van layout without a permanent garage under the bed (which means more space to heat). It is also worth considering (for any van layout) if you expect frequently to be in temperatures below 10F (-12Ā°C) because it has more power to warm up a completely frozen van (left alone without heating) faster.
Again, that’s our opinion, and we don’t pretend that’s the absolute truth. Ask around and you will get all kinds of recommendations. When getting a recommendation from someone else, ask how long they’ve been using their setup, in which conditions, and if they’ve had any issues. Most reviews come from people that just finished their installation and are very excited to share it…Ā Ā
1.3- What brand/model of heater should I buy?
The two original players in the gasoline/diesel heaters are Webasto and Espar. They both offer high-quality products backed by customer support via a network of dealers (Webasto Dealer Locator | Espar Dealer Locator). If you’ve been following us for a while, you know that we invest in quality components; that’s a philosophy we used for our entire build, and it has paid off. For this reason, we highly recommend one brand or the other.
Gasoline
13,650 BTU (4 kW)
Espar M2-B4L
| Item | Buy Link |
| Ford Transit Kit with EasyStart Pro controller | EsparParts.com |
| ProMaster Kit with EasyStart Pro controller | EsparParts.com |
Diesel
13,650 BTU (4 kW)
Espar M2-D4L
| Item | Buy Link |
| Universal Kit | EsparParts.com |
| EasyStart Pro controller | EsparParts.com |
*EsparParts.com is located in the US.
As you can see, we now recommend Espar almost all across the board, except for the 7,000 BTU gasoline model; we still prefer the Air Top 2000 STC over the older Espar B1LC. In 2019, Espar updated their lineup with the new S2 and M2 models: these are pre-wired (greatly simplifying the installation), they feature a built-in automatic altitude adjustment module (nice!), and they come with the EasyStart Pro controller (which has an integrated room temperature sensor). Looks like Espar listened to their customers!
Interesting fact: The footprint dimensions (floor cutouts) are all the same for the Webasto Air Top 2000, Espar S2 or Espar M2; it’s the dimensions of the heater itself that are slightly different:
Webasto Air Top 2000 Dimensions
Espar S2-D2L Dimensions
Espar M2-D4L/B4L Dimensions
1.4- Where to install a Webasto/Espar in a van?
The location of the heater plays a role in heat distribution and hence, your comfort. The ideal placement of your Webasto/Espar depends on your interior layout.Ā
Forward, under the passenger seat
In most vans (Transit, Sprinter, ProMaster), the passenger seat base has plenty of room for a heater (even if you add a swivel); therefore, it’s the most common place to install a Webasto/Espar. It works great with the “raised bed/garage” interior layout because heat distribution is quite uniform. That’s exactly the setup we have in our van:
Cold air is sucked in from the passenger feet area (that’s the coldest place in the van), warmed up, and then expelled at floor level towards the kitchen. As a result, the floor, the living room (swivel seats area), and the kitchen are nice and warm:
Hot air rises, so the bedroom area is nice and warm as well. Shutting the curtain minimizes the heat transfer between the kitchen and the garage; in other words there’s no need to heat the garage. BUT when it’s very cold outside (like below -15Ā°C), heating the garage is necessary so it doesn’t freeze and to control the relative humidity (prevent condensation). So we open the curtain as needed. Therefore, if you are building a winter van, we don’t recommend completely closing the garage in order to allow some heat transfer.
Centered or at the back
Another popular layout features a galley that runs through the entire length of the van, with a table that can convert to a bed in the back of the van. With this interior layout, there is more square feet to heat, and the heat distribution is not as uniform. So if the heat source is installed at one extremity (e.g. under the passenger seat), the other extremity might not be comfortable. We would consider installing the heater in the center (with 2 hot outlets apart from each other, maybe?) if we had this layout.
1.5- Installation Requirements
The Webasto/Espar heaters are very sensitive to inadequate installation!
We. really. mean. it. We met many people down the road that initially had issues with their heater (including us); there’s nothing more frustrating than having heater problems in the middle of the night when it’s -30Ā°C outside (true story). We initially developed a strong love/hate relationship with our heater until we tweaked a few things from our installation (and how we operate the Webasto). Since then, we NEVER use our Propex (our backup heat source) as we much prefer the Webasto. We’ve been using our Webasto without any maintenance since October 2017; we love it.
Here is the secret to an adequate installation: READ THE MANUAL. It’s a long, not-user-friendly, confusing read; so take your time and read it multiple times to ensure you fully meet the installation requirements. We’re here to help, and we like to think you can learn from our mistakes, so below is an attempt at summarizing the installation requirements. It is NOT a complete list, so it does NOT replace reading the manual; it’s more like a list of the common mistakes:
Combustion Pipes Length
- The combustion intake + exhaust length should be less than 2 meters.
- More length increases air restriction, which can result in carbon buildup issues.
- The manual mentions 5m without silencer, 2m with exhaust silencer. However, Tech Webasto still recommended we keep it below 2m, silencer or not.
Combustion Pipes Bending
- Smallest bending radius is 50mm and total bend is 270Ā°.
- Each bend increases air restriction, so does a sharp bend.
- In other words, a straight line is better!
Exhaust silencer
- A silencer adds quite a lot of air restriction. Personally, we decided not to install an exhaust silencer. But many people have them and they're fine...
Exhaust Dumping
- Exhaust must not be dumped under the vehicle; the exhaust pipe must end outside the vehicle edge.
- Carbon monoxide is lighter than air and will pool under the floor, eventually making its way inside the van. Exhaust gas could also re-circulate into the intake and therefore create a rich gas/oxygen mixture, promoting carbon buildup.
Exhaust constant downward slope
- Try to route the exhaust in a constant downward slope.
- Otherwise it creates low points where water can accumulate and increase air restriction.
- Water vapor is a product of combustion (see next requirement).
Exhaust drain hole(s)
- Try to avoid low points. If it cannot be avoided, drill a drain hole (3/16") at each low point in the exhaust pipe.
- Otherwise water will accumulate in each low point and increase air restriction.
- Water vapor is a product of combustion! Not convinced? Look at the photo we took after a night of heating (around -20Ā°C outside). Without drain holes, all this water would clog the pipe.
Fuel Pump Location
- Install the fuel pump as close as possible to the fuel tank.
- To ensure the pump can prime the line and operate as it should.
Fuel Pump Orientation
- Install the fuel pump oriented per owner's manual.
- The following picture is an extract of the Webasto manual, consult the Espar manual if applicable.
Clamps for fuel line
- Use fuel hose clamps only.
- Worm gear clamps do not provide uniform sealing pressure, and as a result air bubbles might form on the low-pressure side (between the fuel tank and the pump).
As we mentioned, this is not an exhaustive list. Please proceed and read the manual! Don’t have time to waste and read a manual? Then you should reconsider installing the heater yourself (or building a van yourself) because requirements are critical for any system to work properly and safely (electrical, plumbing, propane, etc.) šĀ
1.6- Noise Reduction
One of the downsides of the gasoline/diesel heaters is the noise they make:
1- Fuel Pump Clicking (heard outside & inside)
- PROBLEM: Webasto/Espar uses a diaphragm pump; each click sends a specific amount of fuel. The fuel dosage is controlled by increasing/reducing the click frequency. This clicking noise is transferred to the body of the van and can be heard/felt inside the van.
- SOLUTION: The official recommendation is to install 2 x 90Ā° elbow (Webasto Part Number: 65201A) at both sides of the pump. We personally tried that and didn't notice much difference.
- HACK: Installing the pump with a Quick Fist (amzn.to/37gMBfE) reduces tremendously the clicking noise; after doing this, we stopped hearing the noise inside the van.
2- Combustion Exhaust Noise (heard outside)
- PROBLEM: The fuel combustion generates noise; it's like a small jet taking off. This noise is heard mostly outside, not inside.
- SOLUTION: Installing an exhaust silencer (Webasto | Espar: included with the kit we propose) reduces the noise quite a lot.
- NOTE: A exhaust silencer adds air restriction. Because we initially had carbon buildup issues, we removed the silencer, and we have not re-installed it to this day. That being said, we know plenty of people with a silencer that don't have any issues.
3- Combustion Intake Noise (heard outside)
- PROBLEM: Some of the noise from the combustion can also be heard from the intake.
- SOLUTION: Installing an intake silencer (included with Webasto kit) definitely helps reduce the noise. It also acts as an air filter.
- NOTE: The intake silencer doesn't add much air restriction, and we personally have it installed in our Webasto system.
4- Cabin Fan (heard inside)
- PROBLEM: The cabin fan is quite noisy.
- SOLUTION: Not much to do here!
- NOTE: The cabin fan noise is constant (white noise) and even if it's quite loud, we honestly don't really mind it. This is the SOUND OF HEAT, so you'll learn to enjoy it š The powerful fan expels the hot air with a lot of velocity, increasing air circulation in the van and drying your ski boots really fast.
1.7- Carbon Buildup/Sooting Issues
Any gasoline/diesel heater (Webasto, Espar, etc.) is subject to producing soot if the combustion conditions are not ideal. The soot can either be a fine powder or a super hard material that deposits on the surface of the combustion chamber (carbon buildup). Too much soot or carbon buildup will eventually clog the heater, and it will stop working.
Air-fuel ratio is critical for a complete combustion reaction. The perfect theoretical air-fuel ratio is referred to as the “stoichiometric combustion reaction” (Google it!), and in this condition all the fuel is burned completely, thus minimizing the rate at which secondary byproduct (soot) is produced. But we don’t live in a perfect theoretical world, so the actual combustion reaction will either be lean (less fuel in the air-fuel mix) or rich (more fuel in the air-fuel mix).
Lean Burn
(lean air-fuel ratio = too much oxygen)
- A lean combustion (not enough fuel in the air-fuel mix) happens when the heater is used at a lower altitude than it is programmed for.
- According to Tech Webasto, a lean combustion does not damage the heater, but it results in slightly less heat.
- A lean burn is kind of hard to identify actually, it's similar to a clean burn.
Clean Burn
(adequate air-fuel ratio)
- A clean combustion (perfect mix of air VS fuel) happens when the heater is used at the altitude it is programmed for.
- A clean burn is the best compromise between the amount of heat produced and the pollutants (soot) generated. A heater that burns cleanly requires less maintenance.
- A clean burn produces a minimal amount of white fumes coming out of the exhaust.
Rich Burn
(rich air-fuel ratio = too much fuel)
- A rich combustion (too much fuel in the air-fuel mix) happens when the heater is used at a higher altitude than it is programmed for. It can also happen when there is too much air restriction in the exhaust (exhaust too long, no drain holes, too many bends, silencer, etc).
- A rich combustion produces soot. The soot deposits in the combustion chamber and in the exhaust and can become extremely hard (a.k.a. carbon buildup).
- A rich burn produces dense, darker fumes coming out of the exhaust. A very rich burn condition will sometimes produce small explosions (that's the extra, unburned fuel suddenly igniting).
So a rich burn is the condition that promotes soot and carbon buildup. Okay, but how can we avoid it? This page contains all the information to prevent it, but here is a recap of the most common causes:
Installation
- Exhaust too long.
- No drain holes on low point.
- Sharp bend or too many bends.
- No constant downward slope.
Operation
- Heater fired up for less than 10-15 minutes.
- Heater running on "Low" for too long.
- Frequent ON/OFF cycling (without running on HIGH).
- Before shut down, "boost" it for 10 minutes.
Altitude
- Adjust your heater for high altitude and leave it there at all time.
- If your heater has automatic altitude compensation, you have no adjustment to perform.
- At very high altitude (let's say 7,000ft and up), try not to let your heater run on "low" (even if it's adjusted for high altitude).
So let’s be real. In most cases, carbon buildup issues could have been prevented.
When we had issues, we immediately sent our heater back saying it was problematic. After inspection, they found no issues with it. How could that be? We re-installed the heater (after it was completely cleaned by the Webasto crew), and the problems came back. It was hard to digest, but we were left with no other choice than thinking we might be responsible for this. So we completely revisited our installation and the way we operate that thing (keep reading!). Because we changed many variables at once, we can’t tell exactly which one solved our issue. But we can tell that our issues are definitely gone because of these changes. We learned the hard way, and hopefully you can learn from us and prevent problems (instead of fixing them)!
If your heater suddenly stops working for no reason or if it doesn’t want to start, there is a pretty good chance that it’s clogged with soot or carbon buildup. There is no specific fault code for that; you’ll get a bunch of different codes. At this point, you most likely have to change your burner assembly (combustion chamber). We did it in the past and we documented it here:
1.8- Effect of altitude (and how to mitigate it)
The concentration of oxygen lowers with altitude. This has a huge effect on combustion engines or anything that burns fuel really. Indeed, the correct air-fuel ratio is critical for the combustion reaction to be complete (to burn all the fuel).
Gas/diesel heaters are designed to work at sea level. At this altitude, the air-fuel ratio is ideal and the heater burns “clean”. But as soon as you go up a hill with your van and gain altitude, the air-fuel ratio starts to change: there is less oxygen and the heater burns “rich” in fuel (as described in section: “Carbon Buildup/Sooting Issues“). If you spend most of your time at lower altitudes, the amount of pollutants generated is small, and the heater should be able to “clean itself” when it runs very hot (HIGH). If you spend most of your time at higher altitudes, the amount of pollutants is such that the heater can’t clean itself, and it will eventually clog with soot/carbon. As a general rule, 1,500m (5,000ft) is considered high altitude and you might have to take action if you spend an extended period (a few days) above that altitude:
- Santuario El Rosario, Mexico.
- 10,000 feet.
- At this altitude, even in Mexico, it gets COLD. We had to start the heater that night...
Automatic Altitude Adjustment
The following heater models feature an automatic altitude adjustment (no action needed!):
- Webato Air Top Evo 40: Up to 2,200m (7,200ft)
- Espar S2/M2 (new model released in 2019): Up to 3,000m (9,850ft)
- Espar D2/D4/B4: Up to 3,000m (9,850ft) with installation of High Altitude Kit
Manual Altitude Adjustment
The following heater models must be adjusted manually:
- Webato Air Top 2000 STC RV: The diesel "RV" version can be adjusted on-the-fly with the High Altitude Switch
- Webasto Air Top 2000 ST/STC: Must be manually adjusted (see procedure below)
Webasto Air Top 2000 ST/STC High Altitude Adjustment Procedure
The high-altitude adjustment can be performed by a Webasto dealer; they have access to specialized tools that analyze the exhaust gas to validate that the air-fuel ratio is correct at the altitude where the adjustment is performed. Or you can actually perform the adjustment yourself, like we did. To do so, you will need the rheostat controller:
Preps
- At this point, your heater should be connected (electrical, fuel, etc.) and ready to use. The rheostat should be connected to the pigtail labeled as "User Potentiometer" (ours was located near the heater itself). If you're using the MultiControl HD, disconnect it. OK let's do this!
1- Connect the CO2 calibration wire with the ground
- Using any electrical wire, connect the CO2 calibration wire to your system ground. This can be, for example, your negative bus bar.
- Depending on your heater/controller model, the CO2 calibration wire is either brown (look for a 2-wire pigtail; there should be one brown wire and one green wire) or is either grey/red (look for a pigtail with only 1 wire; itās close to the āDiagnose/Thermocall/Telestartā pigtail). It should be located near the extremity of the harness (far from the heater unit itself).
2- Turn the control knob to 12:00
- Or turn it up to 1:00 for very high altitude (around 10,000ft).
- This will fire up the heater. Wait a few minutes. The LED on the rheostat will eventually begin to flash. Go to the next step.
3- Turn the control knob to 9:00
- Or 8:00 for very high altitude adjustment (around 10,000ft).
- Keep the heater running for 3 minutes.
4- While the heater is still running, disconnect the CO2 calibration wire from the ground
- The procedure is over! Let the heater run for an extra 10 minutes (this is just so it reaches a high temperature and stays clean) then turn it off.
5- Did it actually work?
- At this point, a Webasto dealer would analyze the exhaust gas to make sure the air-fuel ratio adjustment is correct... In our case, there is no way to tell if the procedure was successful or not. Gotta have faith! Time will tell!
6- Driving back to sea level
- According to Tech Webasto, a lean combustion does not damage the heater, so there is no need to change the adjustment back to sea level. A lean combustion will not damage the heater but will, however, reduce the heat output by approximately 100-200 BTU/h which is almost negligible.
- We made the high altitude adjustment in 2017, and since then we have been running our heater adjusted for high altitude at all times (even at sea level). We didn't notice the reduced output, and we believe that a leaner combustion actually helps prevent carbon buildup (as discussed with Tech Webasto).
high altitude adjustment is permanent
- It means that if the Webasto is unplugged, or if the main power is turned off, the high altitude adjustment is not lost.
- The high altitude adjustment remains until it is manually adjusted back to sea level altitude.Ā
Adjusting the Webasto Air Top 2000 ST/STC back to sea level altitude
- Connect theĀ CO2 calibration wireĀ to ground.
- Turn the heater control knob to 9:00. Wait a few minutes.
- When the LED on the rheostat begins to flash, turn the control to 12:00, and keep the heater running for 3 minutes.
- While the heater is running, remove theĀ CO2 calibration wireĀ from ground.
1.9- How to operate properly
Heating your van with a Webasto/Espar requires a little bit more proactivity than heating your house. In a house, you simply set the desired temperature, and you can forget about it. With the gasoline/diesel van heater, doing the same might eventually lead to carbon buildup issues in the long run.
True story: when we were initially rookies and naĆÆve, we would set our Webasto to 20Ā°C when in the van and to 5Ā°C when going skiing all day. It didn’t take too long for our heater to clog with soot and completely stop working… (note that we also made little mistakes in our installation, as described in “installation requirements” section above)
Lesson learned: If the heater is left at 5Ā°C all day (to prevent the van from freezing) when it’s not so cold outside (around 0Ā°C and -10Ā°C), the heater might run at LOW for an extended period of time, and it might also cycle (ON/OFF) frequently (depending on the outside temperature). As we now know, this can lead to carbon buildup issues.
Corrective actions: To prevent carbon buildup, we now operate our Webasto Air Top 2000 as follows:
- Instead of running it constantly all day/all night, we take advantage of the Multicontrol HD timers, and we run the heater in short bursts. For example, we set a timer so the heater stops an hour after we go to bed, then runs for an hour in the middle of the night, and then starts again an hour before we wake up. This minimizes the cycling and the duration that the heater spends on LOW.
- Note that the bursts frequency/duration varyĀ a lot with the outside temperature; there is no secret recipe, experience will teach you.
- Remember that higher elevation makes the carbon buildup problem worse. So at 8,000 feet we would not let the Webasto run at LOW at all, while at sea level we’ll let it run at LOW for a few hours without being concerned.
- Before turning the heater OFF, we took the habit of running it at HIGH for about 10 minutes. The idea is to “clean” it before it cools down (in other words, to clean it before soot hardens). Note that we sometime forget and we don’t go crazy with this.
- Do not use your heater for less than 15-20 minutes. This is to let the heater reach a high temperature and clean itself.
Conclusion: Operating a gasoline/diesel heater as described above might sound irritating, but for us it is part of the Vanlife; we got used to it. And to be honest, the way we operate it might be a bit over the top… With a proper installation and at sea level, all of that might not be necessary. But we haven’t had any issues since 2017, so maybe it has something to do with the way we operate it?
1.10- Remote Room Temperature Sensor
The temperature sensor of the Webasto/Espar is located in the heater cold air intake, not in the controller (except for the Espar S2/M2 with EasyStart Pro controller)! This is important to know, as many people believe their heater is wayyyy out of adjustment when they first use it.Ā
Take the case where the heater is installed under the passenger seat: ambient air under the seat is much colder than ambient air in the living space. So setting the temperature of 20Ā°C on the controller is equivalent to setting the temperature to 20Ā°C under the seat; as a result, ambient air in the living space will be much higher than 20Ā°C! It’s not a major issue, but it’s a bit irritating.
Fortunately, there is a way around it. It is possible to install a remoteĀ room temperature sensor. Once installed, the heater will use this sensor instead of the built-in sensor at the cold air intake. We personally installed our remote room temperature sensor near the MultiControl HD, approximately at shoulder height in the middle of the living space (further away from the hot air exhaust). This way, choosing 20Ā°C on the controller means the living space will actually be 20Ā°C!
Temperature sensors are best located at shoulder height in a central location:
Webasto, SensorPush (faroutride.com/sensorpush-review) and Simarine (faroutride.com/simarine-pico) temperature sensors:
EasyStart Pro Controller for (new) Espar S2/M2 models
The controller includes an integrated room temperature sensor. Nice!
1.11- How to activate all timers on the Webasto MultiControl HD
The MultiControl HD is advertised as having 21 timers, and it does. But there is a catch: only one timer can be active, meaning you can’t actually pre-program your heater for multiple ON/OFF cycles. This is due to legal requirements for passenger vehicles.
Fortunately, there is a way to re-program the MultiControl HD to unlock all 21 timers. After this procedure, you will be able to make all of them active simultaneously:
1- Remove the back cover of the MultiControl HD
- Use a small flat bit to pry the back of the MultiControl HD away (pry all around).
2- Connect the brown wire to the second tab of the diagnostic access connector
- The MultiControl HD will reboot. Don't let go! You have to keep the connection until the end of the procedure or you'll have to start over (that's the hardest part!).
3- Select "Service" menu and choose the number of active timers
- Don't be shy, select all 21 of them!
Note: The "Service" menu also has a bunch of other options
- So be careful not to mess with them unless you know what you are doing!
- Change heater
- Adjust min-max duration
- Permanent mode
- Cancel ventilation
- Temperature range
- Show room temperature (a cool feature)
- Unibox set
- Undervoltage shutdown
- Unlock heater (careful with that one)
- Base configuration
Thanks to Marc B. for providing these instructions!
2- Installation
We installed a Webasto Air Top 2000 STC in our Ford Transit van. The procedure will be slightly different if you've got a different van (Sprinter, ProMaster, etc) or a different heater (Espar), of course, but the general principles remain the same.
2.1- Overview
Time Spent
25 hours
We had a lot to figure out at the time, but we hope this guide helps you finish the job faster than us!
Material
| Item | Description | Quantity | Link |
| Heater Kit of you choice | See recommended kit in section 1.3: “What Heater Should I Buy” | 1 | Section 1.3 |
| Mount Plate | *If your kit doesn’t already include one. | 1 | Amazon |
| Ford Transit Auxiliary Fuel Port Kit (per Bulletin Q-228) | Part Number: CK4Z-9B210-A (gasoline Transit) | 1 | eBay |
| Part Number: CK4Z-9B210-B (diesel Transit) | 1 | eBay | |
| Webasto Fuel Line Reducer (7.5mm to 4.5mm) | To connect to the Transit aux. fuel port | 1 | vmacs.net |
| Heat Shield Sleeve 3 feet length | Radiant Heat Barrier for fuel line | 1 | Amazon |
| 3M Undercoating Spray (Rust Proofing) | To seal and protect cut/drilled metal against corrosion | 1 | Amazon |
| 3M SM600L Thinsulate | To insulate the seat pedestal area (you most likely have leftovers from insulating your van!) | 1 | TheSwivelShop |
2.2- Install the Webasto/Espar Under The Passenger Seat
2.2.1- Remove the passenger seat
Remove the 2 screws in the front:
Remove the 2 screws in the back:
Disconnect the wiring harness. The seat is free to go!
2.2.2- Remove the jack and trim the bolt
Take the jack out of the way (it can be re-fitted here afterwards). We had to trim on of the jack's bolt to make room for the heater:
2.2.3- Locate where to install the heater
Good to know
Mount Plate
It is critical to install the heater on a flat surface. This way, the gasket (the large rubber thingy under the heater) can seal effectively and prevent fumes (and carbon monoxide) from entering the cabin. Most likely, your van’s floor is not perfectly flat. That’s why using a mount plate is so important.
The heater must be located so it doesn't clash with the seat base (black structure with the bar code sticker in the photo below), but also so the combustion exhaust/intake, the fuel line, and the installation bolts are accessible under the floor... it's more difficult than it looks because space under the floor is VERY tight!
Looking on top:
Under the floor (this is an "after" photo):
If we had to start over
As you can see, we drilled a hole for each component (intake, exhaust, fuel line, mount bolts). This makes the installation / removal of the heater a real struggle because it is SO HARD to work from under the van (because of the very tight space). If we had to do it again, we would probably do it like this:
- Cut a single “large” cutout in the van’s floor.
- Install the heater on the mount plate (exhaust, intake, fuel line and bolts).
- Secure the mount plate to the van’s floor and seal it.Ā
This way, the installation / removal can be performed from ABOVE the floor (instead of under the floor), which makes things MUCH easier!
Good to know
Rust Prevention
Paint adds pretty finish and colors, but it also plays a critical role: paint prevents metal from rusting. When trimming a cutout (e.g. roof fan opening), drilling a hole, or even when screwing a self-tapping screw in the van (we recommend using cross nuts instead), metal is left bare around the edge and eventually initiate rust. The best way to prevent rust is to restore the finish on the bare metal by applying a layer of primer, paint, and clear coat (your local Auto Parts Store can provide this, and they can match your van’s color). Each layer must be allowed to dry, so this is really time consuming… Second best way to prevent rust is to apply a layer of rust proof undercoating (see “Material” section above) on the edges where bare metal is exposed. This is quicker, but not as effective as restoring the finish; it’s definitely better than doing nothing though.
2.3- Install the Combustion Exhaust
Good to know
Installation Requirements
To prevent carbon buildup / sooting issues, follow all the installation requirements from the manual (as reiterated in our “Installation Requirements” section above)
Following all the installation requirements (length, slope, bends, etc.) left us with little choice: our exhaust is routed near the passenger-side rear wheel. People often point out that installing the exhaust near the passenger door can let the gas get inside the van… But in reality, the doors and windows are always closed when we use our heater; remember it’s cold outside š So we don’t get anything inside the van. Using the door to enter/exit is not problematic either.
2.4- Install the Combustion Intake
We made a mud-deflector-3000 from an old plastic bucket, and it’s zip-tied to the van. Then we attached the intake to it. As simple as that:
2.5- Install the Webasto / Espar Fuel Pump and Fuel Line
2.5.1- Fuel Line
We routed the fuel line (and the fuel pump’s electrical wire) under our Ford Transit as follows:
2.5.2- Fuel Pump
We initially installed the fuel pump using a cross nut and the clamp provided with the Webasto installation kit (not shown in the photo, a small piece of foam as an attempt to dampen the clicking noise):
However, we recently tried to mount the pump with a Quick Fist (amzn.to/39VWWQZ), and the clicking noise reduction is HUGE – to the point where we don’t really hear the pump inside the van anymore. The quick-fist is zip-tied to the tank attachment strap:
2.5.3- Tapping into the fuel tank
Heads Up!
The Transit’s auxiliary fuel port inner diameter is 6mm, which is much larger than what Espar & Webasto recommend (2mm). That’s more volume of fuel to pump and as a result the heater may have more difficulty to start (especially at high elevations) and the fuel line may not stay primed. It may also increases risk of carbon buildup.
We used the auxiliary fuel port for years and it worked (and still works), as described below, but we did have some carbon buildup issues at first and we noticed the heater would loose it’s prime after 24 hours or so.
From now on, we recommend using Espar & Webasto provided fuel standpipe instead of the Transit aux. fuel port. This is per Espar of Michigan‘s recommandation, following an investigation they performed on the Transit.
You will have to completely remove the fuel tank, which is a bit more involving. We don’t have the instructions yet because we still haven’t install the heater on our new van, so for now you can refer to the following threads:
The Transit fuel tank features an auxiliary fuel port and pick up straw; no need to drill! That being said, the auxiliary fuel port comes with a plug; you need to purchase and install the aux fuel pump kit (purchase link under “Material” section in this page).
To connect the Webasto fuel line to the Transit aux. fuel port, we initially made our own reducer out of 5/16" and 1/4" rubber fuel line:
HOWEVER, we later found this Webasto reducer and we would recommend it instead (it minimize the formation of bubbles, that's what we have on our van now):
To install the auxiliary fuel port, the tank must be lowered. So first things first, make sure that the fuel tank is almost empty before lowering it.
Remove the 6 bolts securing the tank and lower it. The tank is surprisingly light weight if emptied. No need to unplug anything, but it won't go all the way to the ground, so use about just anything to keep it higher:
This is how it looks after putting it back together. We protected the Webasto fuel line inside a rubber fuel hose, but looking back many years later, it seems that might be unnecessary as we didn't observe any damage from rocks or any flying object.
2.5.4- Fuel Pump Electrical Connection
The fuel pump has no polarity. In other words, it doesn’t matter which wires you connect together.
2.6- Cabin Exhaust (Hot Air Duct)
We used a holesaw (2-3/8") to create a cutout in the seat pedestal (and restored the finish on the bare edge):
We installed the Webasto outlet on the seat pedestal and we used the provided clamps to secure the duct:
2.7- Cabin Intake (Cold Air)
Simply snap the protective screen on the Webasto intake (sorry no photo, but you'll figure it out!).
2.8- Electrical Wiring
Connect the wiring harness to the Webasto. We routed our harness between the seat pedestal and the floor and then in the driver-side wall all the way to our electrical system cabinet.
Connect your controller to the harness (the rheostat is connected to the pigtail labeled as "Potentiometer", or the MultiControl HD to the pigtail labeled as "Telestart"):
Connect the wiring harness to your 12V distribution (fuse block). Red wire is positive, brown wire is negative. We've got a diagram & tutorial for you if you're still at the stage of figuring things out š
2.9- Remote Room Temperature Sensor (Optional)
We mentioned in the “Theory” section that the temperature sensor of the Webasto is located at the cold air intake of the heater. As a result, there is always a mismatch between the temperature obtained in the living space compared to the temperature selected on the MultiControl HD (the living space is warmer than selected). The solution is to install a remote room temperature sensor in the living space (near the controller): once installed, the Webasto heater will use this sensor instead of the one in the cold air intake. Then the living space temperature will match with the one selected on the MultiControl HD! Here is how to install the remote room temperature sensor on the Webasto Air Top 2000 STC:
There is a resistor hidden somewhere in the wiring harness. The goal is to replace the resistor with the remote room temperature sensor instead:
Here is what the resistor looks like (after we trimmed it). Expect it to be hidden in the wiring harness under black tape, so you'll have to search for it:
We found the resistor near the Webasto heater itself. The remote room temperature sensor is 5 meters long, that was more than enough to route it towards the back of the van:
We installed the remote room temperature sensor near the MultiControl HD, and, since then, the temperature of our living space matches with the temperature we select on the MultiControl HD!
2.10- Starting The Webasto for the First Time
You made it! Ready to fire up!
- Not so fast… we emptied the fuel tank in order to lower it, right? Remember to refill it š On the Ford Transit, the tank must be above 1/3 full or otherwise the pump will only suck air.
- If you’re doing the installation during summer, you should know that the maximum outside temperature (for combustion air) allowed is 20Ā°C. Above 20Ā°C the heater might not want to start or might automatically shut down.
- The fuel pump on the Webasto/Espar is self-priming. There is no need to manually fill the fuel line. However, expect around 2 to 4 false starts before the fuel line is primed (before the fuel reaches the Webasto heater). The longer the fuel run between the fuel tank and the Webasto, the longer it takes for priming.
- A “false start” is when the heater does not detect fire and aborts the startup sequence. It takes about 2 minutes for the abort sequence to kick in. Once it kicks in, the heater stops pumping fuel, and the combustion fan goes full speed to evacuate the excess unburnt gas from the combustion chamber. Let it do its thing. After a false start, the controller flashes to indicate an error; it has to be reset before it can be fired up again.
- Once it successfully starts, let it run at max power for at least 15 minutes. As you know (you read the “Theory” section, right?), once started, the Webasto/Espar should always be allowed to reach its maximum temperature to keep it clean.
3- Review
3.1- Recap of Events and Issues we had
2016
- Installation (July).
- Carbon buildup issues. Heater won't start (December).
2017
- Heater is sent for inspection and cleanup. It's working again.
- Full time Vanlife (August)
- Issues come back (October).
- New burner install (see our detailed How-to). It's working like new. Exhaust silencer is removed, drain holes are added, better downward slope. We adjust the heater for high altitude. From now on we operate our heater as described in "Theory" section.
- A Propex HS2000 propane heater is added as a backup in prevision of winter (we're still nervous about our Webasto). Unless we have issues with the Webasto, we don't use the Propex.
2018
- No issues at all.
2019
- No issues at all.
- Remote room temperature is added.
- We activate all 21 timers on the MultiControl HD.
2020
- Still no issues! It's fair to say our corrective actions from 2017 solved the issues.
2021
- Still no issues! But as winter is coming, we decided to install a new combustion chamber as preventive maintenance.
3.2- What we like / don't like about our Webasto Air Top 2000 STC
- We absolutely LOVE that it's using the fuel from the van tank. This is a MAJOR benefit as we don't have to fill an auxiliary tank (e.g. propane tank).
- It's DRY heat, which is critical in a van. Using the heater lowers the humidity, and we can easily keep it below 40-50% RH in winter.
- The hot air fan is powerful; it dries our gear (ski boots & clothes) super fast.
- The fact that it can be programmed to start/stop automatically is neat.
- Low fuel and electrical consumption.
- It pushed way more heat than the Propex HS2000.
- Gas/Diesel heaters are more finicky than a propane equivalent. They're sensitive to a proper installation and usage.
- The pickup straw will "unprime" if the tank is lower than 1/2 and we go for a drive (the pickup straw is emptied when it's not in contact with fuel). This means it sometimes takes 2 startup attempts the next time to re-prime it.
- More noise than a propane heater.
3.3- If we had to start over
We’ve been living full time in our van since 2017, and we’ve been through a lot, so it’s fair to say we know what works and what doesn’t work for us. SO, if we had to build another van, what heater would we choose? We would go for a gasoline/diesel heater again over a propane heater. We did have issues at first, but we learned a lot an we’re confident we can get it right the next time.
This page (theory & installation) is UP-TO-DATE with everything we learned along the way. That’s how we would do things next time š
3.4- Related Guides
That’s it, you reached the end… but there’s more! We also prepared the following guides, which are very related to the heater topic:
A helpful article. A micro furnace like Webasto/Espar etc are excellent ways to heat.
A strong word of advise or caution ā¦ Always ensure you have a functional carbon monoxide detector. A fuel burning heater is a source of CO and it operates while youāre sleeping. Make sure you have a CO alarm in case thereās a malfunction or problem that causes CO to enter the van cabin while sleeping. This could save your life!
Can I buy a pdf of the information on the heater?
Unfortunately we don’t have a PDF version. You can export this page as PDF with your internet browser (Print -> save as PDF).
Hope this helps, antoine
When you chose the Air heater did you consider hydronic as an option? I enjoy reading your sections where you talk about different options you evaluated and would be interested in your thoughts on hydronic vs. air gas heaters?
Does the combustion intake need to be outside the vehicle. Looking at drawing combustion air from inside vessel cabin but exhaust out side. Do you see any issue with this? Cheers
I wouldn’t do that:
1- Potential for CO2 poisoning.
2- Gas smell will most likely enter the cabin.
3- Loud noise from combustion.
4- Pressure difference between inside/outside may mess up with the combustion.
I’m no expert, but I really think it should NOT be done.
Cheers, antoine
Hallo,
In my Sprinter van, I have an Airtop 200STC with SmarTemp 2.0 control.
Is there a way to adjust for altitudes above 1500M?
Many thanks.
Andrea
My understanding is that the adjustment can only be made with the rheostat (https://amzn.to/3ZxYPu0) per the procedure listed here: https://faroutride.com/air-heater-installation/#altitude.
A Webasto dealer will be able to help though.
Good luck!
antoine
I am on the road now without a heater and was hoping to find someone who could install a heater for me in the next week or so. Iām currently in Tampa but headed towards Atlanta and sc before moving on to Indianapolis where itās really cold right now. Any suggestions?
Hi Antoine, I have just read your article and watched the Rich Built you tube video. He recommended looking at your details.
Before I install my Esbar in 2 weeks time, I wondered if I could drop a new rigid 2mm pick up pipe down the Ford Aux 6mm pick up pipe so I wouldn’t have to remove the whole unit from the tank?
Thanks
I honestly don’t know if this can be done. Not sure if the 2mm pipe will fit in the 6mm… Someone has to try š Please report back if you give it a try!
I had the same question and would love to learn about any results. I had also considered finding some way of reducing the factory pipe and was curious what others came up with. Waiting on delivery of my transit so Iām still working on theory and design so I have no way to get hands on and dig in yet.
Greetings! Thank you for your wonderfully informative site. Readers – make your purchases through this site to support Isabelle and Antoine and the fabulous content they post!
I’m interested in your thoughts re. Greg and Andrew’s earlier questions, especially related to attaching the mount plate to the van floor:
“Can you expand on your āIf we had to start overā section in which you talk about cutting a large hole for the fuel and intake and exhaust pipes. I donāt understand your comment on āsecure the mount plate to the vanās floor and seal itā. Would removal consist of removing the mounting plate and the furnace.? How would the mounting plate be secured to the floor?”
Hello! I have been following your build journal rather religiously. I see that you have the installation of the Webasto listed rather far ahead of the electrical system setup, but then say the electric system is a pre-requisite for the Webasto install. I am a bit confused. Help?
Question….
I was able to get Multicontrol into service mode but I think it may be stuck there now and quick start button is always lit? Anyone else run into this?
Just to be clear. Do you use plus nuts in the floor of the van to mount the mounting plate to, so that you can remove the heater along with the air exhaust, supply and fuel lines, from above?
Thanks
We did not, we have to access everything from below, which is a pain. Next time I’d make it so we can access from above!
Hi Antoine. Sorry to bother such a quiet board. And I couldnt find how to start a new message with you, so I am replying to maybe a relevent question.
I am curious if you feel that ethanol fuel gives you any issues with the heater. I have a gas E-350, and I am debating to get a gas powered air heater and tie it to my tank, which is often filled up with 10% max ethanol, or if I should opt for a diesel and get a small gallon (or smaller) tank to keep inside the van (similar to what you see on all the cheap China heaters).
To solve your un-priming issue below 1/3 tank and to resolve high altitude start issues caused by low vapor pressure of gasoline install a 2mm pickup straw in your tank instead of the 6mm factory auxiliary fuel straw. A straw can be fit through the cap of the fuel level sending unit without having to drill the tank. This solves all Espar un-priming and high altitude start issues. You can also put the straw lower in the tank if you wish to be able to run the tank to lower fuel levels.
In your or Webasto’s view, does the use of high octane gas help reduce carbon/soot buildup? Thanks, Howard
I don’t know this but I did trade gasoline for a bit of my career and I think the ethanol in the fuel is part of the issue. Which doesn’t change based on octane rating. Ethanol tends to gum up smaller engines like lawn mowers, weed eaters, etc. so it could be causing some of the same issues here. Having said that, I would think a higher octane rated gasoline could help alleviate some of the issues too.