Van Diesel Heater Install

Updated on September 29th, 2020

As summer turned into fall, and quickly to winter here in New Hampshire, we realized that if we wanted to keep using the van in the winter we would need some sort of heater.  We wanted to keep using the van, so we started researching options and landed on doing a diesel heater install.

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Diesel Heater Install Materials:

• The Diesel Heater
• Plywood
• Zip Ties
• 3M 5200
• Fiberglass Cloth
• Plastic Wrap
• Epoxy Resin
• Hose Clamps

Diesel Heater Install Tools:

• Ratcheting Crimping Tool
• Wire Cutter/Stripper
• Drill
• Oscillating Tool

How Did We Decide on a Diesel Heater?

There are three types of heater commonly used in camper vans: electric, ventless (propane) and vented (diesel or gasoline) heaters.

Electric Heaters

Electric Heaters are very simple and easy to use, but due to the amount of electricity they use they almost always need to be used with shore power. They are portable, don’t produce exhaust and provide dry heat. We use electric heat when shore power is available, especially if we aren’t paying.

Ventless

These are typically a catalyst type of heater that runs off propane. Unfortunately, since the combustion gases are not vented outside, moisture and carbon dioxide build-up can be a problem.  Ventless heaters can be a good option to “take the chill off” in mild climates where you don’t need it to run all night. Just be sure to crack a window when it is in use. 

Vented

These include pretty much any heater that has flue or exhaust pipe to the outside which include wood stoves and forced air heaters (diesel, propane, gasoline). Since these heaters are not introducing any moisture or carbon dioxide into the air they are suitable for continuous 24-7 use.  Their installation can be more complicated and they are typically more expensive than the other two options but in the long run ,we think it’s worth it.

Type of Heater	Pro	Con
Electric	Inexpensive Easy Installation Dry Heat Portable	Power Hungry Requires Shore Power
Ventless	Portable Easy Installation Powerful	Moisture Build Up Carbon Dioxide Build Up Not Recommended to Us While Sleeping Can Be Expensive to Operate
Vented	Dry Heat Minimal CO Danger Low Power Usage Fuel-Efficient	Some Models are Expensive Complicated Installation

We decided to go with a Chinese copy of the Espar forced-air diesel heater for a number of reasons:

• Automatic thermostatic control.  No getting up in the middle of the night to light or stoke a fire.–Also Andy’s not great at making fires.
• Exhaust vents outside
• Diesel is inexpensive, readily available, and has a low flash point. Don’t believe check out some of the videos on youtube of people throwing matches in cups of diesel.
• Low Cost. At about a tenth the cost of an Espar
• Very large support group on Facebook 

Bench Testing

We highly recommend testing the heater outside the van before you install it. If there are any oils leftover from the manufacturing process, they can be burned off without stinking up the inside of your van.

Additionally, we had heard that quite a few of these units have some issues right out of the box and ours was no exception. The blower motor was rubbing on the control box which prevented it from turning.  It appeared that the fan was pushed too far onto the motor shaft and about ¼” of the shaft was protruding from the fan. I was able to get the fan to slide back out so it was flush with the end of the motor shaft and it rotated freely.  I’m not sure if was pushed too far on at the factory or it was bumped during shipping. 

After fixing the fan and purging air from the pump, it fired up and ran nicely.

Finding a Mounting Location

These heaters, when installed in a vehicle, are designed to be mounted through the floor. This set up leaves the majority of the heater on the inside with just the combustion air intake, exhaust, and fuel pipes sticking through the floor.  

We had several locations in mind as possibilities when we ordered the heater: behind the driver’s seat, under the bed on the driver’s side and just behind the side doors on the passenger side. There are a few things to take into consideration when finding a location to mount the heater.

• Location of floor support channels, frame rails, body mounts, wiring, fuel tanks, brake and fuel lines, etc. All that stuff on the outside.
• The spot should be protected from road debris and tire spray from wet or snowy roads.
• Furniture and cabinets on the inside of the van.
• How will the exhaust from the heater will be run?
• Is there a spot for the pump to be mounted?

After lots of trips under the van on the mechanics creeper, measuring and remeasuring, I settled on just behind the side doors on the passenger side.  This spot was wide open underneath, protected from road debris and tire spray. The only downside? It wasn’t hidden under a bed or in a cabinet and would require some sort of enclosure on the inside to hide and protect the heater.

Diesel Heater Install

Cutting the hole 

Since the heater is designed to sit directly on the steel floor of the van I had to cut away a section of the plywood subfloor. We made this opening 1/4in larger than the mounting plate in each direction. 

Before cutting the large square hole in the floor to accommodate the mounting plate, we first drilled a small hole to triple check the location. When I was satisfied with that I traced the four mounting holes from outside of the plate onto the metal floor of the van.  Then I drew a rectangle on the floor about ¾ of an inch inside of those four holes. When I cut out the rectangle, we end up with around an inch of overlap between the mounting plate and floor. 

When we were satisfied with the layout, we drilled a hole in each corner of the rectangle to make a starting point for cutting the hole. We started out using the jigsaw and a fine metal blade. Later, we switched to the oscillating tool because the jigsaw blade was a bit too short.

Afterward, we used a file to remove any jagged edges from the hole and dry-fit the mounting plate and heater.

Electrical

The supplied wire harness for the diesel heater only has three connectors, a fused power, and ground wire.  We connected the ground and power to our fuse block and opted to remove the inline fuse holder that came with the unit. We recommend adding a switch to the positive wire that you can turn off when the heater is not in use. For some reason the display stays on all the time regardless of the heater is on or off.  We have just been pulling the fuse when it’s not in use. 

The two-pin locking connector is for the fuel pump, this gets routed through the slot in the mounting plate and under the van where the fuel pump will be eventually mounted.

The triangular connector hooks to the control unit. We chose to mount it on the pillar near the door where we have our light switches mounted.  The control unit has a built-in thermostat so you will want to mount it somewhere it will get an accurate measurement of the interior. 

Finally, the rectangular connector plugs into the main diesel heater unit itself. 

Fuel Pump

Mounting the fuel pump takes a little extra consideration since it needs to be mounted at a 45-degree angle and with the outlet on top and the inlet on the bottom. Additionally, it makes a ticking noise when the heater is running so you definitely don’t want it mounted inside!

We mounted the fuel pump to an unused hole in one of the body mount brackets, hoping that mounting it to the frame rather than the body would reduce the noise.  We can still hear it a little, but it’s not too bad. 

Fuel Lines

The kit came with quite a bit of stiff nylon fuel line, a section of rubber hose and a bunch of little clamps.  The section of rubber hose is intended to be cut into approximately two-inch sections to use as connectors between the nylon line and barbed fittings on the filter, pump, and heater. 

We ran fuel lines from the heater to the pump, then to a temporary tank sitting on the ground for testing purposes before we sorted out the permanent fuel tank. Zip ties were used to secure the lines every few inches while keeping them away from hot or moving objects. Where necessary we also sleeved the nylon line with a larger diameter piece of tubing line to provide additional extra protection.

Exhaust and Intake

After sorting out the fuel lines, we mocked up the exhaust and intake lines. For the exhaust, we ran it down from the heater itself and out near the wheel well. The whole thing is at a slight downward angle so any water or condensation will drain. The exhaust was attached to the heater unit with a hose clamp and stainless steel wire to hold it in place under the van. Remember the exhaust gets very hot keep it away from anything flammable or temperature sensitive!

The intake was routed up on top of the frame rail, in a spot that is nice and dry and out of the way. You will want to make sure that your intake and exhaust are not next to each other! The intake was attached to the heater unit with a hose clamp and held in place with zip ties.

Testing the Diesel Heater Install

Once everything was in place we fired the heater back up and ran it on high to make sure it didn’t get too hot or that there weren’t any issues with the mounting locations. We wanted to make sure everything worked and fit together before sealing everything up.

Sealing Everything Up

After successfully testing, we took everything apart, and installed the mounting plate using 3M 5200 marine adhesive sealant. Mostly because it was the best stuff we had laying around but this stuff is gold. Once that cured, we reinstall the diesel heater unit, and all of its plumbing and electrical.

Installing a Diesel Fuel Tank on a Gasoline Van

Installing a diesel fuel tank on a gasoline van was probably the hardest part of this project. A couple of things we were taking into consideration.

• We didn’t want to mount the tank inside. Diesel stinks, and once it gets into fabrics or wood it never comes out.
• Our van doesn’t have a spare tire rack or anything hanging off the back that would make for a good place to mount it to.
• We still needed to be able to fill the tank and access it.

We couldn’t make the tank that came with the heater work, so we bought a small 2-gallon tank that could be mounted to the frame rail and lower down to fill. Andy thought he wanted to make the mount out of plywood, but when he mocked it up he found he really didn’t like it, but he did figure out where he wanted to mount it this way. We settled on fabricating a fiberglass bracket that would hug the tank and mount to the frame rail.

Using the 2-gallon plastic tank as a mold, Andy wrapped it in plastic wrap and covered it in fiberglass cloth and epoxy resin. Once it cured he sanded and painted it. He then drilled a few holes in the bottom to allow water to drain out if necessary and four holes in the sides. We then used two large hose clamps to strap it to the frame. This allows us the ability to move the tank if necessary or remove the whole bracket.

We have been using a bungee cord to hold the 2-gallon tank in the fiberglass bracket and that has been working great.

Make It Look Pretty

The final location of our diesel heater install was in a spot we were using for our trash can. We didn’t want to lose that horizontal space so we built a plywood box around the heater to both protect the heater and give us a small shelf that we could put the trashcan back on.

We took the van out for our first winter adventure after the diesel heater install. It got down to 6F overnight and we were still toasty warm!

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