Diesel Air Heater Installation in a DIY RV Camper Van

Diesel Parking Air Heater Install in our Promaster Van:

There are three major energy users in most RVs. These are cooking, heating water, and heating the interior air. Our DIY RV Promaster van needs to do all three of these tasks. We have already tackled our water heater solution. This blog post will cover how we accomplished heating the interior air of our van.

Our DIY RV design is electric only – no propane system will be installed. Most RVs have a propane water heater and propane furnace to heat the interior. We opted for a small, diesel powered parking heater to heat our interior space. These diesel parking heaters (brand names include Propex, Espar, Eberspächer, and Webasto) can be expensive. However, there are many generic diesel parking heater options for under $150. The designs are all very similar and fairly basic, so we opted for one of the Chinese diesel parking heaters for our Promaster RV van.

Electric space heaters use battery capacity very quickly, but the diesel parking air heater turns out to be quite efficient. We will elaborate later, so let’s jump into the heater details and the installation process.

Diesel parking air heater components for our DIY RV Promaster Van
Diesel parking air heater components for our DIY RV Promaster Van

The image above shows the typical components in a diesel parking heater kit. Our kit had one long air outlet pipe which we cut to size. The filter (for the intake) was too restrictive, so we replaced it with a model that was more open but had a screen. The 10 liter tank is thin but large in the other dimensions, so we replaced that with a shoebox size 5.5 liter fuel tank.

The location of the heater is one of the first goals. The heater needs to be able to pull air into the unit and exhaust hot air out. These are on the bottom of the diesel parking heater. We decided to install our heater on the floor of the Promaster van. In order to allow the hot exhaust pipe to maintain a good air gap from our flooring material, we cut two 3 inch holes to create an oblong void under the heater.

Diesel air parking heater hole through the van floor.

We lined our cutout with aluminum flashing and caulked with high temperature RTV sealant. The kit included a flat metal mounting plate to mount the heater to the van flooring. We trimmed this plate so that it would fit better under the edge of our wet bath shower pan. It is much easier to connect the exhaust, intake, and fuel lines to the bottom side of the heater body before installing into the van. The photo below shows this completed. The heater is ready to install onto the floor. The intake is the lighter weight black tubing on the left. The middle clear tube is the hard fuel line. The right silver tubing is the stainless steel exhaust. All are attached with hose clamps after the flat mounting plate is attached to the bottom of the heater.

Diesel parking air heater exhaust and intake.

The picture below shows the underneath side of the van after the heater has been mounted to the floor. The intake tube was turned and run about 18 inches towards the front of the van. The better screened intake filter can be seen clamped to the bottom side of the metal van floor. The wiring and fuel line to the fuel pump were wrapped in split loom wire tubing and attached with zip ties along the framing member. The exhaust runs toward the back of the van. The muffler or silencer was installed pointed slightly downward at the end of the exhaust tubing.

Diesel parking heater underneath the DIY RV van
Diesel parking heater exhaust and intake detailed.
Diesel parking heater exhaust (circled in blue), and intake (circled in blue)
Diesel parking heater replacement fuel tank.
Diesel parking heater replacement fuel tank.

The image above shows our replacement fuel tank on the right. The tank that was included in our kit was not practical due to its size. We purchased a 5.5 liter fuel tank and mounted it under the hood next to the driver side headlight housing. The fuel line then is routed through a fuel filter and along our water heater hoses to the fuel pump under the van near the heater. It is best if the fuel tank can be located higher than the parking heater. The fuel pump should be closer to the heater with a slight upward tilt (15 to 45 degrees).

Diesel parking heater LED controller.
Diesel parking heater LED controller.

Our diesel parking air heater came with the LED controller shown above. This is a very nice controller that can display a good amount of information. The animated icons indicate if the fan is running, if the glow plug is on, if the fuel pump is on, six levels of internal temperature, the current air temperature in Celsius and the desired air temperature in Celsius. The display is always on, so we installed the power switch (shown above the display), to be able to fully power the unit and display off. The black plastic panel to house the on/off switch is 1/8″ thick ABS plastic. This Install Bay ABS Plastic Panel material is very useful for panels for switches and other controls. It is 1/8 inch thick with a texture coating on the finished side. Note that the heater should only be shutdown using the controller. Powered should never be suddenly removed from the unit when it is running. The controller will put the unit through a shutdown and cool down sequence when it is turned off. Not allowing this shut down to properly happen will overheat and damage the unit’s electronics.

Diesel parking heater location in our Promaster RV van.
Our air heater is located under the wet bath.

We are very pleased with the performance of the diesel parking heater. It allows us to heat the interior without a propane system. We chose a diesel heater rather than gasoline for the perceived safety of diesel along with the lower cost of the unit. We can easily top off the diesel fuel tank for the heater when we stop for fuel as we travel. The combustion uses outside air and exhausts all combustion gases outside as well.

Our experience has been that 1 liter of fuel will last about 8 hours or during the night with temperatures in the low 40s to upper 30s, which is when we primarily would run the heater. Our 5.5 liter fuel tank will last about 5 nights when used during the coldest night hours. Electricity usage is minimal as well. The unit pulls about 8 amps when the glow plug is on to start combustion when the unit is first started. After about 3 to 5 minutes, combustion is established and the glow plug is no longer needed and turned off. The fuel pump and fan then only draw 0.5 to 1.5 amps depending on how fast the blower is needed.

Products and Tools used in this project:

Diesel Air HeaterDiesel Parking Heater Kit
5.5 Liter Fuel TankAlternate fuel tank, better size to mount under the Promaster hood
Install Bay ABS Plastic Panel12 x 12 inch plastic material, 1/8 inch thick, nice textured finish for creating any size panel for switches, https://www.dhiverse.org.uk/cheap-kamagra/ dimmers, and knobs
Round Button Toggle SwitchOn / Off switch, about an inch in diameter, used to fully power off the diesel heater and controller
DrillCordless drill to drill pilot holes and larger holes
Drill Bit SetDrill bit set for pilot holes and mounting plate screw holes
3 inch Hole Saw3 inch hole saw for creating an opening in my flooring plywood and insulation
2.25 inch Hole Saw2 1/4 inch hole saw to drill holes in the metal van floor for the exhaust and intake
Painters TapePainter tape, helpful to mark locations on the top of the floor to indicate obstacles below
Wire Split LoomSplit wire wrap to protect wiring and fuel line running under the van
Zip TiesZip ties with a screw hole attachment to secure wiring and fuel line
Galvanized StrapStrap to secure hoses, tanks, fuel lines, etc.
High Temp RTV SealantSealant to seal around metal mounting plate and aluminum flashing inside floor opening

We also have produced a YouTube video detailing the Promaster RV diesel parking air heater install that provides more detail. Click the image below to view the video.

Diesel parking heater YouTube video.

Happy Trails…

Update: We had some questions about our diesel fuel tank mounting, so here are some pictures with more details… Pardon the dirt, these were taken after about 10,000 miles were put on the van after the initial heater install.

Diesel heater fuel tank top view.
Diesel heater fuel tank side view.
Diesel heater fuel tank front view.

10 thoughts on “Diesel Air Heater Installation in a DIY RV Camper Van”

  1. Do you have any other photos that showed how you set up the plastic tank under the hood for the fuel? I see you’ve a block of foam that a piece of plywood (that is secured with a bracket) is resting on that is the base for the plastic fuel tank, and then there is a system to strap the tank in securely — that’s all very inventive! Anyway, if you have any other photos or video of how you did all that, I’d sure appreciate it. Also, did the plastic fuel tank you ordered come with a vented cap? Apparently, a vented cap is recommended, so that as the fuel is spent and the pressure changes in the tank, the cap can draw in air to balance out the pressure in the tank.

    • I used a piece of closed cell foam on the bottom of the 1/2″ plywood to cushion the tank over the items below. The plywood is sealed and painted black. I used a metal strap attached to the bottom of the plywood and then secured to the one bolt near the hood support arm. A large metal band clamp holds the tank to the plywood base, and it did use some closed cell foam to prevent the strap from rubbing or cutting into the plastic tank. My cap does have a tiny hole for a vent. It has all worked very well. NOTE: I added some photos to the bottom of this blog post that show more detail on the tank mounting under the hood. Thanks for asking!

  2. Well I’m curious how your heater is working? Are you totally happy with your install? Any issues/problems so far? Etc. I am particularly intrigued with how you put the gas tank under the hood — how’s that working out? I notice that a lot of people put their heater under the passenger seat, but you chose a location that’s different — are you happy with that?


    • Yes, totally happy with it. No issues that we have seen. The tank under the hood is great. It is efficient enough that I don’t have to fuel too often, and under the hood keeps it protected and outside the interior space. I do like our location under the side of the shower pan. It was extra space for us anyway, and it is located closer to the rear bed, which makes it nice when I turn it on about an hour before we get up in the morning. I kept the jack under the passenger seat and added other tools to that case, so I would hate to lose that storage anyway. Hope that helps you!

      • Thanks, yes, that helps. I think your placement of the fuel tank under the hood is ingenious, and I hope to do the same thing. I ordered the plastic tank with the link you provided, and finally received it, but was disappointed at how cheap it seems — but as you report no problems with it, it must be fine, right?

        • I don’t know if they get different batches of plastic tanks, but mine has held up fine. No leaks, no problems. It is fairly well protected under the hood, so I am not too worried. Good luck with your install.

  3. Really appreciate the details on this work. The link for the 5.5 fuel tank seems dead. Do you have dimensions? I’ve found some other ones that look similar but want to be sure they fit.

    • Since it is diesel fuel, more like oil than gasoline, it will not explode. I had some of the same concerns, but after talking to some other people, it did not seem to be a serious safety issue.


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