Diesel Air Heater Installation in a DIY RV 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, 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…

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