What I Used
My heater system is based around the Webasto Air Top STC. This heater comes in both a diesel or gasoline (petrol) version. Since my Promaster uses gasoline I used the gas version.
If you start shopping for this unit you’ll probably notice two things pretty quickly. One is that there are quite a few “knockoffs” of this heater available on eBay and other places that are considerably cheaper. I can’t speak to these in terms of quality and reliability. Secondly, you’re likely to run across a Russian company called Heaters4You that sells the genuine Webasto unit for about half the price of any North American distributor. The primary caveat that I’m aware of with the lower priced Russian imports is that they don’t come with a North American warranty. However, from what I can tell, warranty service on Webasto heaters in North America is pretty bad anyway. Also, you can literally buy two kits from Russia for the same amount as a single kit from a North American vendor.
I had read that at least a few people had successfully ordered from Heaters4You and had good experiences, so I decided to save about $500 and order from them as well. I figured that if I had any type of issue, ordering another brand-new kit was probably a faster and more reliable solution than trying to wrangle warranty service in North America for the same price.
I placed my order through the Heaters4You website on July 24th, 2019 and it arrived in Florida on August 1st!
To further complicate matters, some information on the interwebs suggested that the Webasto 2000 STC was not officially supported in North America at all and that only the, slightly older Webasto 2000 ST (no C at the end) was supported. I don’t know if this is still the case, but I suspect it’s not since I see that Sure Marine is selling the STC model on their website. If anyone knows the full story on this, or has other recommended vendors, I’d love to hear from you!
Below I have detailed two ways of obtaining the heater and the parts you might need. One from Amazon and another from Heaters4You with Amazon links for certain items when possible. Each list of parts represents as closely as I can what I bought and installed. Of course, you may need more or different parts.
Purchasing From Amazon
- 1x – Webasto Air Top 2000 STC gasoline/petrol heater. This Amazon-sold kit comes with the heater itself, a rubber gasket for the bottom of the heater, the basic (rheostat-style) controller, combustion intake and exhaust hoses with an intake silencer, fuel pump with fuel line fittings, mounting plate, 60mm ducting, air outlet grill and all the wiring. Amazon
- 1x – Webasto 60mm threaded outlett grille. Note this Amazon-sold kit comes with one of these, I used two so this is for the additional one. similar item on Amazon | Heaters4You
- 2x – Webasto 60mm “backing nuts” – Amazon | Heaters4You
- Dorman 800-123 Bundy fuel line connector (pack of 2) – Amazon
Purchasing From Heaters4You (With Amazon)
- 1x – Webasto Air Top 2000 STC gasoline/petrol heater. The Heaters4You “kit” comes with the heater itself, a rubber gasket for the bottom of the heater, the basic (rheostat-style) controller, combustion intake and exhaust hoses with an intake silencer, fuel pump with fuel line fittings and all the wiring. Heaters4You
- 1x – Webasto mounting plate – Amazon | Heaters4You
- 2x – Webasto 60mm threaded outlet grille – similar item on Amazon | Heaters4You
- 2x – Webasto 60mm “backing nuts” – Amazon | Heaters4You
- 1x meter of 60mm ducting – Amazon | Heaters4You
- Dorman 800-123 Bundy fuel line connector (pack of 2) – Amazon
Finally, one part that I did not buy and wish I had known about is the remote air temperature sensor. If you don’t have this remote sensor, the Webasto uses an air temperature sensor that is built into the fresh air intake. So, regardless if you use the “analog” (rheotat) controller,or the fancier, digital “multicontroller” with timer, neither is a “thermostat” in the same sense as what you might be used to in your home. They do “set” the desired temperature but the actual “sensor” is either in the heater itself or that remote sensor. Since hot air rises and the Webasto in generally installed at floor level, the air going into the built-in sensor is much cooler than the air at the height you might install your controller. So, I recommend adding the remote temperature sensor and locating it where it actually makes sense to “monitor” the air temperature.
Update October 2020. A reader of the blog named Spencer kindly wrote in and let me know that the current version of the Webasto STC 2000 does NOT support the remote air temperature sensor that I wrote about (and struck out) above. Heaters4You wrote to him and said “I must to inform you that Webasto heater Air Top remote temperature sensor is not compatible with Webasto Airtop 2000 STC. Webasto removed this function from new heaters Webasto Airtop 2000 STC. They also removed a connector for the remote temperature sensor from wiring.” From what I can tell, this means that the ONLY temperature sensor is the one that is built into the air inlet of the Webasto. Since hot air rises and the heater in generally installed at floor level, the air going into the built-in sensor is much cooler than the air at the height you might install your controller which is good to know about when setting the controller temp.
Note: you need the standard, rheostat-type “controller” to put the heater in “high altitude mode” which I recommend for everyone. More on that later in the post.
The Webasto is installed in the same place that I put my Propex heater in the first two builds – directly behind the driver seat on the floor.
The Webasto documentation (link to Webasto Air Top STC manual) makes it clear that there needs to be an airtight seal between the bottom of the heater and the surface it’s attached to. I wanted to install the heater directly on the metal van floor rather than the plywood subfloor. So, I cut out a section of the subfloor for the heater. However, the van floor is NOT flat in this area – there are the structural corrugations in that spot which is where the mounting plate comes in. In addition, the bolts that come with the Webasto to mount it to the surface are pretty short. Also, I wanted a way to remote the heater from inside the van with relative ease if (when) it needed service. So, I decided to fasten the heater to the mounting plate and then attach the mounting plate to 1″ tube steel that I painted black.
That assembly or “sandwich”, from top to bottom, is made up of the heater, the rubber gasket, the mounting plate and then the tube steel.
You can see that the mounting bolts for the Webasto are “below” the bottom of the tube steel. This allows the entire assembly to be fastened through the van floor with 4x screws that are placed on the far edges of each piece of tube steel. This means that, if (when) I need to pull out the heater, I can remove the clamps holding the heater’s combustion air hoses, disconnect wiring and the fuel line from below, remove the screws holding the assembly to the floor and then pull that entire thing up.
Inside The Van
Below is a photo of my installation from above. You’ll see the heater itself mounted on the metal van floor using the mounting plate (details above). Eventually, I would box this in so that it sort of lines up with my galley cabinetry.
Below The Van
Pictured below is what this all looks like from underneath the van. In this photo you can see the combustion air intake hose with it’s “silencer”, the combustion air exhaust hose and the fuel line and fuel pump for the heater.
Once I had the heater “assembly” (above) built, I attached the combustion air intake (plastic hose) and combustion exhaust (stainless steel hose) to their respective connections on the bottom of the heater.
There is some wiring that comes out from combustion air intake connection and a “slot” in that connector. This wiring connects to the fuel pump and the slot allows you to route the wire “outside” of the intake hose itself. It’s an odd setup.
Below is a photo of the connections on the bottom of the Webasto heater.
Next, I prepared to mount the heater “assembly” including the hoses to the floor. The Webasto comes with a paper template for locating where the holes should go including the combustion air intake and exhaust hoses, fuel line connector and the 4x mounting bolts. Since I was not using the 4x mounting bolts (heater was already mounted), I marked the locations for the holes which were the combustion intake and exhaust and fuel line. In addition, I marked another hole location for the wiring that would supply power to the fuel pump which I put directly adjacent to the combustion air inlet hole since this wire comes through it’s “slot” in that location.
Once marked, it’s a good idea to double check that the heater will fit in the spot you want to put it before you drill those holes! I also recommend drilling a small “pilot” hole in the center of one of the combustion hose locations so that you can go below the van and “see” where these hoses (and the other connections) will down there so that you can make sure there is adequate access. I confirmed all of this and then drilled each of these 4x holes in the van floor. This was difficult at times since a few of the hole locations “spanned” a floor rib.
With the floor holes drilled, I was able to push the combustion intake and exhaust hoses through the floor and drop the heater “assembly” into place on the metal van floor and screw down the entire assembly from above through the tube steel.
Next, I moved onto the gasoline fuel line. Very conveniently, there is a built-in auxiliary fuel pickup on Promaster vans! To access this port, you remove the floor panel that is between the seats in the cab. Underneath this panel you’ll see something like the following.
There is a sort of “cap” on the auxiliary pickup that comes off easily enough. From there it’s simple to “snap on” the Doorman Fuel Line Connector.
The Webasto kit that I ordered came with fuel hose and some slightly larger sections of hose that the smaller fuel hose can slide onto. These larger bits of hose act as “couplers” and one of these can be used to connect the outlet on the Doorman connector to the fuel line. The kit also included plenty of clamps. From there, the fuel hose curves around the front section of the fuel area and then down below the van toward the pump. This area is “open” to the elements so there is no need to drill any holes and the hose is rigid enough to simply poke through this area from the top and then be able to find that hose from below the van to pull it into the location where you’ll be installing your fuel pump. I ran the fuel hose inside blue, 3/8″ plastic tubing that I had leftover from another project which serves as a sort of conduit to protect the fuel hose itself.
At this point I spend some (more) time under the van!
First I chose a place for the fuel pump and installed it. The kit comes with a clamp for the pump and I used a #10 stainless steel self-tapping screw to fasten it to a support beam.
Then I routed the fuel line to the pump and also connected the pump’s outlet to the fuel inlet on the Webasto itself. I decided to “prime” the fuel line that ran from the van’s gas tank down to the Webasto pump. I did this by simply sucking on the fuel line until the gas flowed out. Try not to do that. Gasoline is a horrible thing to have in your mouth! I also routed the fuel pump’s electrical wires to the pump. All of the fuel lines and wires are protected in wire loom.
Next, I mounted the combustion air inlet “silencer” that was provided with the kit, cut the plastic hose to the correct length and connected it to the silencer.
Then I routed the stainless steel combustion exhaust hose away from the heater and to the driver side of the van. It is important that there are no low points or dips in the path of this hose where water from the exhaust vapor can collect. If there are low points, it’s recommended that you drill a 3/16″ hole at the bottom of the hose at each low point to let water escape. I tried to route my hose so that it sloped evenly down to the side of the van. You also want to create a downward bend in the hose where it meets the van sidewall as shown below.
Note: you should make sure that there is some distance between the combustion air intake hose and the combustion exhaust hose and that these face away from each other.
With all the hoses and wiring routed, I sealed up all of the holes from below the van. I sealed around the combustion exhaust with High Temperature RTV Silicone and the other holes with Loctite Marine Sealant. When the sealants were dry, I sprayed them with grey primer.
Back inside the van, I turned my attention to wiring up the heater. The gaggle of wires that come with the Webasto seem very confusing when you first encounter them. Or at least they did for me! However, once I began laying out the wires in the relative direction they were going to go (i.e.: toward the fuel pump, up toward the rheostat controller, etc.), the wiring harness started to make more sense and since each connector is unique it made it easier to determine which “lead” went to which device/part.
Once I had a sense of how the wiring harness worked, I removed the access panel from the top/front of the heater to connect up the main, 18-pin electrical connector to the corresponding connection inside the heater.
Then I connected the analog, rheostat-syle controller that came with my kit to the cable that extends from the wiring harness. The wiring for the controller is sufficiently long to place it pretty much wherever you’d like it. In my case, the controller was mounted just above the heater, behind the driver seat a bit forward of my galley area. None of that stuff was installed yet so, at this time, I just laid the controller on the driver seat.
Finally, I connected up 12VDC power wires to a temporary supply cable that I had run from by battery bank. On the Webasto wiring harness, the red wire is positive, brown is negative and it comes with a built-in fuse. To wrap things up, I also put on the plastic protective “screen” that covers the air inlet on the “back” side of the heater (opposite the hot air outlet).
Turning It On
Yay! The moment of truth! With everything seemingly ready, I turned the knob on the rheostat all the way to 11. It was summer in Florida (a million degrees) so I wasn’t sure it would turn on at all but it seems that the turning the knob up to 11 (all the way to the right/fully clockwise) forces the heater to turn on even if it is summer in Florida.
When first powered on, the Webasto turns on the fan at a slow speed and then, after about 30 seconds or a minute (never timed it), you can hear the pump engage (making a clicking sound) and shortly after that the heater should turn on with the fan increasing in speed once there is combustion. Notably, whenever the heater is “on” and regardless of where the controller’s rheostat knob is set, the fan will run at low speed constantly.
When I turned on the heater I heard the fan and eventually the pump engage but it did not start. So, I turned it off and then on again to repeat the sequence. I did this about three times and eventually it stopped running and the green LED on the controller knob started flashing indicating that there was a fault. Below is a screenshot from page 75 in the manual that details the various faults and how to read them. Basically, when there is a fault, that green LED on the rheostat-style controller will blink 5 times quickly and then will come on for a series of longer flashes. In my case there was one of these longer flashes which was the pattern for the “no start (no flame formation)” fault. That pretty much lined up with my theory that the gasoline wasn’t making its way to the heater. To “clear” a fault, according to the manual you, “briefly switch the heater on and off (at least 2 seconds) to reset fault lockout”. I did this and after another attempt, the heater actually fired up and hot air starting coming out!
Webasto Air Top 2000 STC Fault Codes
High Altitude Mode & Why I Recommend It For Everyone
Now that everything was installed and seemed to be working well, I wanted to enable “high altitude mode” on the Webasto heater while all the wiring was still accessible.
According to Webasto, heaters should be put into “high altitude mode” if you’re going to above 5000-6000 feet because as you get higher in altitude the fuel to air (oxygen) mixture being fed into the burner gets too “rich” which can lead to accumulation of carbon in the burner.
But, why would I do this when I’m in Florida at sea level? In my research I came across a lot of people (Far Out Ride in particular) that had many issues with carbon build up and their Webasto heater. By enabling “high altitude mode” you reduce the chances of carbon build up by forcing a “leaner” air to gasoline mixture and the only apparent downside is that you loose a tiny bit of the heating power (3-4% BTU).
So, here’s how to do it:
First, as I wrote above, you’ll need the basic, rheostat-style controller for this procedure.
In the main wiring harness, there is a wire that you need to “ground” in order to change the mode. It seems that Webasto changes the colors of their wires sometimes so, from the main wiring harness (that connects up to the heater), you should look for a two-wire “pigtail” with either a brown and green wire or a red and gray wire (mine was the brown/green combo). It’s pretty far down the wiring harness – far away from where the harness connects to the heater. Once you find that proceed with the steps below.
- First, you’ll want to connect the brown (or gray) wire to “ground”. For example, you’d take a length of cable that is temporarily spliced/connected to the brown (or gray) wire and connect the other end to either bare metal on the van (ground) or the ground terminal on your van or camper battery.
- Turn on the heater and set the knob on the controller to the 12:00 position.
- After a few moments, the green LED on the controller will begin to flash. At this point turn the controller knob to the 9:00 position.
- Keep the heater running with the controller knob set to 9:00 for 3 minutes.
- While the heater is running, remove the brown (or gray) wire from whichever “ground” you have it connected to.
How Does It Work?
For many months after I completed the van I was in Florida and it wasn’t cold enough to test.
But in early December, 2019, we left for a two-month trip from Florida to California and onward to Colorado. Of course, we took the “southern route” since it was winter but we encountered plenty of cold (for Floridians) nights along the way. So, we ended up running the heater most nights in most places.
Overall the heater performed awesome. It heated the van quickly and efficiently. Many people complain about how loud it is but I didn’t find it any louder than the Propex heaters I had used in the past. The one notable difference in sound is that, with the Webasto, you hear a “click, click, click” sound when the fuel pump is running whereas there is no need for a fuel pump with a propane heater. Both the Webasto and Propex have a fairly loud exhaust sound if you’re outside near that area of the van but, with my well-insulated van, I don’t hear that inside. However, it is something you should be aware of and “listen to” if you have these heaters to know how it might affect your camping neighbors. We camped at State Parks, National Parks, Walmarts, back roads, BLM land, urban streets and everything in between and never had an issue with the sounds inside or outside.
Toward the end of that trip, we drove from northern California to Colorado in late January 2020 where the bitter cold pushed the limits of the Webasto heater. Our coldest night was in Wyoming where the outside temperatures dipped to -15 degrees Fahrenheit. The heater ran constantly but it wasn’t enough to stay warm. During those really cold nights across the high plains, my experience was that the heater could make the inside of the van about 40-45 degrees Fahrenheit warmer than outside temperatures. So, even if it’s literally freezing outside (32 degrees Fahrenheit), that’s plenty to stay comfortable. But, when it’s ridiculously cold it couldn’t keep up.
For some context, my van has 3/8″ closed cell foam insulation on the floor and 3M Thinsulate throughout the walls and ceiling. So, it’s pretty well insulated. However, in addition to the cab windows, I have a CR Laurence T-Vent window in the slider door and 2x Motion windows in the rear doors. The cab windows have insulated covers but the other three windows only have roller shades. It’s well known that the greatest area of thermal loss in a camper van is the windows. So, with less windows or perhaps insulated window coverings for the slider and rear windows, the Webasto might have performed even better.
I was also impressed with the fuel efficiency! According to Webasto, the gasoline consumption is anywhere between .04 to .07 gallons per hour. That seemed to line up with my experience. Most nights we’d let the heater run at our desired temperature all night with no noticeable difference on the van’s fuel gauge in the morning. It’s great to fill up on gas and not have to worry about adding additional fuel like propane.
Overall, the installation process is somewhat complex, as you can tell from this post, but the heater works great and I would definitely recommend it for a van camper!