Installing an Espar Heater in a Sprinter Camper Van

Installing an Espar D2 heater in our Sprinter camper van was something we almost skipped. With 20/20 hindsight and many sub-freezing nights logged on this road trip, it is officially one of our favorite things in the van, with the fridge (perhaps) beating it out by a sliver. Except that I’m writing this post during a rare rainstorm in Joshua Tree and our heater is cranking away keeping my fingers warm while I look out at the desert, so the fridge is losing points fast! (For more background on our full build-out, check out the adventure mobile post.)

All in all, our Espar has been absolutely fabulous. We’ve run it about 50 150 hours so far without any issues whatsoever. One thing I’ve heard from blog readers is that the high altitude kit can be handy or else the unit will soot up and need to be serviced. That said, we’ve spent days and days above 6,000′ elevation and our Espar hasn’t required a cleaning yet. When it does, this is a handy resource for trouble shooting the unit, cleaning it out and hopefully fixing the problem.

Since I spent a fair number of hours dealing with the install and couldn’t find much except scattered and often incomplete forum posts on the InterWebs, I wrote up the following install process for how I put in our Espar D2 heater. (Installation of the Espar D4 heater is exactly the same, so far as I can tell.) I highly recommend doing it in a heated shop, or in the summer while drinking a cold beverage, rather than the November weather in Idaho that I experienced. Sleet, snow and rain are sub-optimal install partners…

Perfect Espar heater installation weather.

Perfect Espar heater installation weather.

Where to Buy It

I shopped around online and bought our heater from EsparParts.com. I also considered Snugger, a cheaper clone of the Espar, but there weren’t many reviews. (There are occasional deals on Ebay too, from what other readers have told me.) Either way, you’ll save a bundle versus buying from a dealership.  If you’re doing the install yourself, definitely buy online!

Deciding to do the install myself was a simple process after getting quotes of $1,000-$2,000 from the brain surgeons apparently needed to do the work. RIPOFF ALERT. The install may sound intimidating, but you can do it! And if you screw it up, hey, vans are cheap – buy another one. Your loving partner will understand, right? If not, you can sleep in your freezing-cold van…

Frankly, you can do this install. Dozens of blog readers have used my writeup to successful install a (working) Espar heater in their van. Grab fortune by the britches and get after it! (Yep, I just used britches in a sentence.)

Why I Bought an Espar D2 Heater versus D4

I went with an Espar heater because 1) it can run on diesel, which means I could tap into the main fuel tank for our van and avoid installing propane or other fuel sources and 2) everyone else did it and Sprinter Jedi Mind Control works on me.

I bought an Espar D2 heater, which is smaller than the D4, after reading that you want the heaters to run on “boost” (high power) in order to avoid fouling the combustion mechanism inside the unit.

Our van is insulated with anywhere from R-11 to R-14 on the walls and ceiling (none in the floor) and so far the heater has kept us warm down to about 22 degrees in the cold and damp redwood forests of the Northern California coast as well as the dry and freezing desert nights in SoCal.

Fuel economy on these things is amazing. Even at full boost mode, it burns just one gallon of gas in 20 hours (!), and it doesn’t run that high most of the time. (It’s apparently 50 hours per gallon at the lowest heat level.) For the heat output, it is quite an efficient unit and seems well worth the price.

In case you are considering not getting a heater: If your van is insulated and lacks an internal heat source, it will turn into an ice box. Some people may think body heat will warm up your van. From personal experience and testing this on numerous shorter trips prior to this one, I can say this… They. Are. Wrong. Put in a heater or your less cold-resistant partner is going to stay home while you road trip alone.

Install Tips

Set aside a weekend for the job. I did it in a day, but that doesn’t include the initial trip to auto parts store to get supplies.

Recruit people to help. An unsuspecting friend, or incredibly helpful father-in-law (thanks again Steve!), will make life 12x easier.

Getting the Sprinter up on blocks or a hoist to get more space under the van will make your life 1.2 million times easier. It can be done without it – I survived – but take my word for it. Your elbows and back will thank you. Especially if it’s sleeting and the ice water pools under the van on the tarp…just sayin’.

Sub-optimal working conditions... At least my father-in-law is under the van while I'm cramped in the bike garage.

Sub-optimal working conditions… At least my father-in-law is under the van while I’m cramped in the bike garage.

Something to watch out for: while the wires for the thermostat and heater power are 12’ long, the pump wire is only 7’ long…which can (did) create some issues depending where you place your heater. Why they don’t make the wires the same length, I have no idea.

-Strong recommendation: install a combination smoke/CO detector in your van. They’re small, cheap and can save your life.

If you have an ‘08 or newer Sprinter (the NCV3 or newer), you do NOT need the ~2′ fuel pickup pipe that comes with the unit. The helpful folks at Mercedes put a fuel tap on the front left side of the fuel tank that makes it quite easy to install the tubing without dropping the fuel tank and drilling a hole in the top. YES.

-Buy the $36 muffler from BunkHeaters.com. Our heater sounded like a rocket headed to Mars before I installed the muffler two months into our trip. Your neighbors in camp will appreciate it, trust me. It’s a super easy install.

Consider installing the high altitude kit if you are going to be camping at elevation (such as the Rockies). This avoids fouling the Espar (the elevation messes up the fuel/air mixture). I didn’t do it, but it is worth considering. (Update Jan 2017: For what it’s worth, we’ve spent many nights above 6,000′ with the heater running and have not had issues in three years.)

I read about some guy cutting off the “extra” wiring harness on the unit after he installed the thermostat and fuel pump wiring. That’s the diagnostic port! Leave it there.

The fuel pump wiring will not go through the same routing hole as the intake/combustion beneath the unit. You have to run it through the floor of the van somewhere else.

Connections You’ll Need to Hook Up

  1. Intake air for combustion from outside the vehicle – black flexible hose provided with the unit.

  2. Exhaust air from combustion to the outside of the vehicle – silver, heat-resistant ribbed metal hose provided with the unit.

  3. Fuel line from the main diesel tank under the van, routed through the fuel pump that comes with the heater (more below on that specific item).

  4. Thermostat control wiring – this stays internal to the van. Just follow the color-coded instructions on the wiring, it’s straight-forward.

  5. Power wiring – I ran this directly into a fuse in our 12v panel.

  6. Intake/Heating air ducts – I installed our heater so that the heating air snout for the heating unit pokes into the main living space, with the intake end of the unit in the bike garage. This has worked well and air circulates through the van without running a large amount of duct work, which I wanted to avoid. The air temp of the hot air isn’t too high, but I’d recommend at least 6-12″ of open space so you don’t roast your floor or other surface in the van. Installing under the front passenger seat seems like a popular option, but that’s where our subwoofer goes (priorities, right?) so I can’t speak to that personally.

Here is how I went about installing the heater in our 2013 Sprinter (same as 2008-2013). Please note this is the same process as 2007 and earlier models except that you’ll need to drop the fuel tank and install the fuel pickup that the Espar D2 or D4 heaters come with. Check out www.sprinter-source.com for information on that.

Install process

  1. Figure out where your heater is going to go and measure all wires, duct work, and fuel lines to make sure you have enough material. Then add 10-20% slop so you avoid stretching wires tight or running out of fuel line halfway. I ended up having to relocate the fuel pump and the shorter wire presented a headache.

  2. To attach the stock Mercedes Sprinter fuel tank to the Espar fuel line, read all the directions in the installation manual and then perhaps follow what I did:

    1. Buy a short (<12”) piece of 5/16” black flexible fuel line, two clamps to fit it and a metal male-male connector that is ¼”.

    2. The 5/16” fuel line slips over the fuel tap from the Mercedes tank. Then you insert the ¼” connector into that, which then inserts into the ~3/16” (5mm) fuel line that comes with the Espar D2. Make sure to clamp all connections.

    3. Clamped down, the fuel lines are snug around the connector and you can run the 5/16” fuel line directly to the fuel pump for the Espar heater. The instructions clearly give you max distances and orientation for everything.

      1/4" male-to-male adapter prior to putting on hose clamps.

      1/4″ male-to-male adapter prior to putting on hose clamps.

  3. The fun (scary!) part: cut a 4×6” rectangle in your wood floor. Note: you can cut all the way through the metal, but I don’t recommend it. Instead, just cut through the floor (a hole saw worked great for me) to get the clearance from the exhaust pipe and then drill smaller holes that allow the intake/combustion pipes to exit. There is a template provided with the heater that makes this easy. File down sharp edges on the holes and install heat-resistant muffler putty on the wood. I also folded up some aluminum foil and lined the inside of the wood just to reflect some heat back. Probably overkill, but it was easy.

    Paint to seal the cut, file and a hook blade to cut through the flooring.

    Paint to seal the cut, file and a hook blade to cut through the flooring.

    Two 4" hole saw cuts and holes drilled for the fuel line (center) and intake/exhaust.

    Two 4″ hole saw cuts and holes drilled for the fuel line (center) and intake/exhaust.

  4. The seal that comes with the heater will mash down on top of the floor and seal out grime and dirt. I don’t think it is necessary to cut a huge gaping hole in the metal when it just takes a couple holes.

    Holes cut and sealed with heat resistant putty behind the reflective foil.

    Holes cut and sealed with heat resistant putty behind the reflective foil.

  5. You’ve got your holes drilled. Before routing the intake/exhaust pipes, clamp them to the unit. Otherwise you’ll be doing it on your back and it will be impossible or make you hate life and any word starting with “Espa…” A little foresight here saved me some serious pain.

    Heater with piping clamped and ready to install.

    Heater with piping clamped and ready to install.

  6. Fuel line and intake/exhaust ducting run? Route any internal ducting, or at least think about where it is going to go. Perhaps reference step #1 again.

  7. Run your thermostat, power and fuel control wiring per the diagrams. (See how easy that was? Just one sentence that will take you a couple hours. Enjoy! )I think connecting to the house (not engine) battery is the best way to go since you don’t want to drain the battery that starts the engine.

    Test install for the heater. Flipped it 180 for the final go at it.

    First install for the heater…BACKWARD. *Slaps forehead* The finned silver end puts out the heat. Easy to flip around at least. Note to self: read instruction manual.

  8. FIRE UP THE BEAST. At first, all you’ll hear is a clicking of the fuel pump as it fills up the fuel line for the Espar. Do not despair if the unit “malfunctions” and says there isn’t enough fuel to start combustion. Reset it and do it again. It took three times through for ours to start. In the meantime, I cursed, kicked some stuff, and practiced other Zen methods of stress control. The manual doesn’t tell you to just let it run. I hopefully just saved you some frustration and early gray hairs.

That’s it! The details are in the the instruction manual and will cover most of it, yet I think a few little pointers like this could have saved me a considerable amount of time.

Drop me a line if you have any questions about your install. First question is free and then I demand Synergy kombucha drinks delivered cold to my van door after mountain bike rides! Cheers to staying warm on the road.

50 replies
    • Dakota
      Dakota says:

      Ha! Don’t be…that thing was a ton of hard work to get installed.

      Your propane heater (even if you don’t use it) still gives you backstop capability when the mercury really starts rattling in the bulb!

      Reply
  1. Hilary Bourassa
    Hilary Bourassa says:

    This was a tough post for me to get through with my laymen knowledge of installing stuff, but I am sure that there will be some super-stoked Sprinterites out there who are thankful that you took the time to post your experience!

    Reply
    • Dakota
      Dakota says:

      Ha, too funny. I had a disclaimer at the top so regular readers who are non-Sprinter owners would know not to read it. Thanks for caring enough to get through such a boring post! 🙂

      Reply
  2. P.
    P. says:

    I so appreciated this post as I have been researching putting a heater in my 2004/ 2500 sprinter.
    I just ordered one from BunkHeaters.com but when I asked them about the $36 muffler you mentioned they said they had no such product??!!??
    Wondering what’s up with this? I and they couldn’t see anything on the web page for muffler?
    Again.. We so appreciate your taking the time to post about your experience with this.
    P.
    Hood River, Oregon

    Reply
    • Dakota Gale
      Dakota Gale says:

      Yo yo P! Glad it helped out. That’s what I like to hear.

      Not sure what to say about the muffler. They had them when I bought mine about 9 months ago and I haven’t thought about it since. There must be other dealers out there that have them.

      What kind of conversion are you doing for your van? Toy hauler, road tripping mobile or…?

      Cheers!

      Reply
      • P.
        P. says:

        hmmm…. weird. I’ll check with them again about the muffler?
        My van has been converted (toys, joy and work … on site retreat catering) for a couple of years but I’m in it enough on the fringe months and am tired of being cold while I sleep and would like to be able to hang out with more comfort too. Been using a ‘mr. buddy’ unvented propane heater just to take the chill off but it is after all ‘unvented’…even though they say they are safe…
        Again.. thanks for the info. Waiting for it to arrive in the mail.
        P.

        Reply
        • Dave
          Dave says:

          Thanks for the guide. Going to tackle this project this weekend. “P” I bought the heater from bunk, but they said they didn’t stock the muffler but that it could order it. I ended up going with esparparts.com for the accessories (high alt fuel pump, muffler, and exhaust end cap)

          Reply
  3. kent
    kent says:

    So I have a 2007 and it is NCV3. Are you saying that the 07 NCV3 doesn’t have the special port on the fuel tank? Also, I have a 170″ wheel base sprinter would you still recommend the D2 vs D4? Thanks, Great write up.

    Reply
  4. Dakota
    Dakota says:

    Hey there Kent. So far as I know, the 2007 and newer vans do not have the port on the fuel tank. Definitely worth verifying online or just by crawling under the rig – it should be on the driver’s side near the front. It’s very easy to find (if it’s there).

    I would still recommend the D2 heater. The D4 is a far more robust heater and is designed for a big floor area. I’m sure there are people who would disagree with me, but I bet you’ll be in good shape with the D2. Worth checking around on the forums though!

    Glad the write-up helped and all the best with your rig. Where are you located and what kind of build are you doing?

    Reply
    • Kent
      Kent says:

      I am located in Portland and we use the van for weekend trips and road trips across the U.S. so far it is insulated with a bed, couch, vents, electrical(inverter, 12v outlets, 6 LED lights) I am hoping to add the heater and some cabinets. Maybe redo the floor.

      Reply
      • Dakota
        Dakota says:

        Sounds like a great rig! Perhaps we’ll run into you in Portland sometime when we’re back in town. Always fun seeing other builds that people have done and meeting up with fellow Sprinter owners. Cheers and Happy New Year to ya. Good luck with that Espar install!

        Reply
  5. Chris
    Chris says:

    Thanks for taking all the time to share your experience and lay out all this info!! How noisy is the heater with the muffler installed? Would someone who walks by the van obviously know that it is running? Also, how did the heater effect your stealth camping?

    Reply
    • Dakota
      Dakota says:

      Glad it helped! Someone walking by can definitely tell the heater is going. If you’re concerned about noise, the Espar isn’t a good choice.

      That said, we’ve never, not once, had anyone knock on our van and ask us to move, and we’ve run the heater in many cities. It was pretty cold outside when we ran it though, so there weren’t many people walking around!

      Reply
      • Dennis
        Dennis says:

        OK, one question: how did you secure the fuel line to the underside of the Sprinter? After all the work we’ve done on our Sprinter, the rest of the install seems almost straightforward…

        Reply
  6. Stumpjumper 29R
    Stumpjumper 29R says:

    Thanks for posting this. I have been on the fence about installing the Espar. After reading your post I have decided to go ahead and tackle this on my own.

    Reply
    • Dakota
      Dakota says:

      Do it! I’ve had at least a dozen people follow the the install I did and end up on the winning side (which is to say, with working heat and no inadvertent holes in the van). Good luck…and here’s to riding that Stumpjumper.

      Reply
  7. Martin Burzynski
    Martin Burzynski says:

    Thank you for the the Espar tutorial. We have a 2013 170 Sprinter “VANdal” built by out Outsidevan. Although the we have a generator and AC with reverse heat I want to add the espar heater as we are transitioning from 2-3 months long adventures to full time travel. Question: I would like to install the Espar in the steel box support under the passenger seat with the heat producing end facing aft and air intake facing front. Will that work or the will the heat buildup be too much under the seat? I was thinking of cutting out an opening in the back of the seat slightly bigger then the Espar heat producing end and covering it with a painted to mach the interior grill. Any advice will be greatly appreciated. And if you get a chance check out our blog LivingVANdal.com.

    Reply
    • Dakota
      Dakota says:

      Hey Martin, I think the Espar installation under the front seat is a great option. Other people have done it, including others that have emailed me, and I think it’s an excellent use of space. I put our subwoofer in there (priorities, ha!) so our heater had to go somewhere else, but otherwise I would have seriously considered that. So long as you have a few inches around the unit, I bet you’ll be fine. We love ours and I think it will be a great addition to your van.

      Reply
  8. Sarah
    Sarah says:

    Awesome tutorial! Thanks for sharing all of your hard work 🙂 I have one major question that’s been keeping me from making a final decision on what type of heater I’ll use: Does the Espar produce any water vapor from the combustion of the diesel? I mean, it has to, but I’m wondering if does enough for you to notice it? My Sprinter is my full-time home. The conversion materials are mostly wood, and I don’t want to have mold issues. Also, I’ll be taking it on ski trips this winter and don’t want a heater that’s only going to add to the wetness of my clothes, boots, etc. I’m leaning towards a wood/solid fuel stove for that reason. But diesel would be way easier and more convenient. Any insight? Thank you so much, again!!
    Sarah

    Reply
    • Dakota
      Dakota says:

      Hey Sarah! I think you’ll be fine. I don’t know how much vapor could be in there, but I suspect it’s not much given that the heat comes directly out of a red-hot combustion chamber. Relative to the moisture coming off your body, wet ski boots, and food, any vapor in the exhaust outlet should be extremely minimal.
      Also, I would go with the Espar for both convenience and for space. Wood stoves can take up a lot of room. Hope that helps!

      Reply
  9. spencer
    spencer says:

    i just bought a lightly used D2 to replace the military multi fuel heater that i installed just a couple of weeks ago the MF heater draws something like 300 watts and is very noisy. so the Espar should be a big improvement.

    the unit did not come with a controller and with just three wires to be connected to one. it was removed from a tractor so it was working as wired. i have read the manuals and the wiring diagrams bit it is not totally clear what wire does what and i would prefer to not burn up the electronics. two of the wires were cut in the previous intstallation but are still there if choose to use them for either a factory controller or just a switch etc. ideally i would like to duplicate the rheostat control but can not find specs on the rheostat resistance or what wires to connect to. the wires that are remaining are the brown/ white (sensor ground reference) the yellow (switch on signal) and the grey/red (set temperature value does the yellow get connected to +12 volts to turn the unit on and the other two leads get a variable resistance to set the temperature using the internal sensor on the cool air intake side? if so (or if it is something else all together) what value resistance is needed to cover the temperature range? most control circuits i have set up use a voltage for control with a potentiometer between + voltage and ground but this does not have enough wires to do that.
    spencer recently posted…Our CrewMy Profile

    Reply
  10. steve Ward
    steve Ward says:

    Hey I am trying to install an Espar D2 heater in my 2016 MB 4×4, is the diesel nipple you speak of a black capped tube on the driver side of the tank? Thanks!

    Steve in Durango

    Reply
    • Dakota
      Dakota says:

      Yep, sure is! Congrats on your new rig – that’s a sweet setup. I’d totally have gotten the 4×4 if it had been out when we got ours. And hell yeah to Durango – I loved my visit there last April!

      Reply
        • Dakota
          Dakota says:

          Hey Steve, feel free to add a pic to a comment over at the Adventure Mobile page if you’d like (Just click “our van” at the top of the page). I don’t have a forum or reader pics page set up because I’m a Blog Dictator. Nah, just haven’t wanted to deal with it.

          I checked out the circus that you created – super cool. See you in Durango sometime!

          Reply
  11. James Wong
    James Wong says:

    Dakota,
    Thanks so much for this very helpful and detailed D2 install guide. You’re right—it’s a challenging install, but certainly doable for the DIYer. I used your info and installed my D2 in my ’06 2500 140. The 2006 and earlier Sprinters don’t have a fuel pickup to tap into. Instead of hassling with dropping the fuel tank, I used a brass “T” barb to tap into the existing fuel line for the heater booster. I ran the wiring loom for the Espar fuel metering pump through the existing wiring bundle boot under the driver seat. Another real helpful tip is to pinch the van’s fuel line just before the fuel filter in the engine compartment. This keeps the fuel in the fuel lines while doing the tap in work underneath the van. Thanks again for sharing your build info!!!

    Reply
  12. Amanda Clifford
    Amanda Clifford says:

    I bought my van two weeks ago and am currently in the information overload phase. I’m in the to propane or not propane phase. I’ll be in the van full time and am afraid that a fridge will draw too much on the electrical system if I spend a few days not driving around. That being said propane seems like a good option. I’d run the furnace and fridge off propane, everything else off of the solar system. Any suggestions? Any reason you went with the Espar instead of a propane system?

    Reply
    • Dakota
      Dakota says:

      Welcome to the Van Info Fire Hose! You’ll sort it out. 🙂

      The Espar is an easy solution and I liked the way it plugged into a big fuel source (the main tank) instead of a propane tank. I didn’t want to deal with a big propane tank to keep our ground clearance solid and not have a big tank in the van. Still, many people have tanks mounted under their vans and do just fine. For full time, a 3-way fridge with a big propane tank and solar to supplement could be a great option!

      Reply
    • Paul
      Paul says:

      Propane creates moisture, and I like you have a van but I am not keen on carrying a 20ld propane bomb around . the only pro pane I use is for the cooktop and I use the 1lb green camping bottles they last a long time . my battery source is 220 amps run my engle fridge and spar just fine for 3 days boon docking a lot depends on your needs The espar is the the way to go on the heat source Camped last year in southern Colorado at -5 degrees van was 65degrees all night it is so efficient I run only kerosene keep it in a backpacking fuel bottle

      Reply
    • Dakota
      Dakota says:

      We use it to dry clothes and shoes all the time. It would be simple enough to have a piece of ductwork that would route into a box where you could really focus the heat!

      Reply
  13. Tim Lieberman
    Tim Lieberman says:

    Using this site as inspiration and looking for someone to tell me I could do this install, I took the plunge last weekend. I have a 2012 144 Sprinter in Seattle and chose to install an Espar D2 behind the 3 person bench seat (and I’ll box it in later, perhaps with a subwoofer). A CD rom came with the unit and the instructions were pretty straightforward. Cutting a hole in the floor is the scariest part, but just make sure to measure 8 or 9 times before taking the plunge…and it’ll work out…or at least it did for me. Running the fuel line, connecting the hoses, fashioning a nice plate of metal to mount the unit was all easy and fun. With the wiring I ran into two issues (one super simple). First, the fuel pump power in didn’t mate with the wiring harness (called a Loom in EU)…both had female adapters. I read the wiring diagram for quite some time to make sure I wasn’t missing something, and the wire colors matched…so I cut off one side and added the males. The other issue I had, which was more confusing, was with the 801 series thermostat. The optional outside temp sensor wiring confused me. I followed the directions and what was left was the brown neutral wire from the harness. Again, I consulted the wiring diagram trying to figure it out…and my conclusion was the brown wire isn’t needed. The grey wire from the thermostat is also not needed (b/c I didn’t install the optional outside temp sensor)…or at least this is what I’m going with! I fired up the unit and it took several cycles for the pump to pull diesel from the tank, but it worked and is a beautiful thing…heat without the van being on (I have a 100W PV system and 100ah battery). I find the unit to be quite quiet though it’s not boxed in yet and the jet engine sound from outside is not really audible inside the van (I’m fully insulated, but not on the floor). I can see how the muffler (they also make a cat converter) would be good if you’re planning to camp near other folks…the jet engine sound is real! Not too obnoxious if you don’t have one (I don’t yet)…Thanks for the great write up.

    Reply
  14. josh blumental
    josh blumental says:

    Silly question… I see your section about the barb and the fuel hose, but what exactly are you hooking into on the diesel tank? I have the cold weather package on mine and it has the coolant heater hooked up to the quick connect port of the tank? Is there a second port? Do you use a T or Y connector to that port? Do you have any images of that portion o the instal?

    Thank you

    Reply
    • Dakota
      Dakota says:

      Ah, good question! I think a T or Y connector could work, but I haven’t done that so I can’t speak to it from experience. I bet someone on the forums have written about it though. Worst case, you drop the tank, drill a hole and install the fuel tap into the diesel tank. Good luck!

      Reply
  15. Gareth
    Gareth says:

    Dakota, I have a more detailed question about your connection to the auxiliary fuel port. I noticed yesterday after filling my tank that I had a leak at the port and the fits compression fitting. Did you use a male to male connection at the auxiliary junction?

    Thanks,
    Gareth

    Reply

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