Gas/Diesel Heater DIY Install Guide for Vans (Transit/Sprinter/ProMaster)

Gasoline

Diesel

Cold air is sucked in from the passenger feet area (that’s the coldest place in the van), warmed up, and then expelled at floor level towards the kitchen. As a result, the floor, the living room (swivel seats area), and the kitchen are nice and warm:

Hot air rises, so the bedroom area is also nice and warm. Shutting the curtain minimizes the heat transfer between the kitchen and the garage; in other words, there’s no need to heat the garage. BUT when it’s very cold outside (like below -15°C), heating the garage is necessary so it doesn’t freeze and to control the relative humidity (prevent condensation). So we open the curtain as needed. Therefore, if you are building a winter van, we don’t recommend completely closing the garage to allow some heat transfer.

Remove the 2 screws in the front with a 10mm hex socket:

Remove the 2 screws in the back with a 10mm hex socket:

Disconnect the wiring harness with a 7mm hex socket and detach any clip attached to the seat:

Put the seat aside and remove the liner to get access to the seat pedestal:

Remove the inverter/bracket assembly from the floor with a 10mm hex socket, and disconnect the electrical connectors:

If you want to reuse the inverter, remove it from the bracket with a T-25 torx bit and an 8mm hex socket:

There is a plastic liner at the bottom of the passenger pedestal:

You can trim it to facilitate the next steps:

Remove the four 15mm screws and then the seat pedestal:

Seat pedestal removed!

Mark the hole contour and center. You can use the 67mm (2-5/8″) hole saw as an aid:

Use a center punch to mark the center of the hole (optional, but it prevents the drill from roaming on the surface; highly recommended for your build!). Then pilot the center hole with a 1/8″ drill bit (or such). At last, make the hole with a 67mm (2-5/8″) hole saw:

Debur with a file (or a deburring tool), smooth the edge with sanding paper, clean with Isopropyl alcohol, and then seal with primer and topcoat:

Note: Some YouTubers recommended daubers (shown below), I still prefer Q-Tips for relatively short edges…

Trim the two inverter’s studs flush:
(first time using an oscillating tool 😬)

Success! This thing makes it SO easy! It doesn’t cut like butter, but the final result is dead flush and clean:

While I thought I would just “make” the cutout and move on, I actually spent most of the morning (yep) finding the location of the cutout by transcribing the undercarriage frames using the spot weld (mostly). The areas between the dashed lines are no-drill zones:

Here’s what’s happening under the floor:

The EsparParts.com kit comes with a mounting plate. It’s a generic plate to accommodate various installations, it is a bit larger than what we need for our specific case. The sides of the plate will be trimmed as follows (hatched areas), and new holes will be drilled to match the holes present in the foam seal:

This is to clear the bulge (near the inverter’s stud), and to clear the valley in the floor, which could both prevent a good seal between the mounting plate and the floor (very important to avoid carbon monoxide from being ingested inside the van). This is also to clear the no-drill zones (undercarriage frames):

The final result after trimming the four sides with a jigsaw (thick metal blade). Note that the four original holes are gone, what we see below are four holes that I drilled to match the foam seal holes (included with the kit):

The foam seal was trimmed to match the new contour (this photo was taken a few steps later…):

Note: I was on autopilot and painted the mounting plate. This is actually stainless steel and doesn’t have to be painted 🙂

First, drill a small hole to validate the location of the cutout (better safe than sorry) and drill a hole large enough so that the jigsaw blade can pass through:

Trim the contour with a thin metal blade:
NOTE: Use painter’s tape to protect the surface from the jigsaw! I forgot, and there are scratches all over the floor…

Meanwhile under the floor:

Drill the four holes that will attach the mounting plate. I will be using M6 rivet-nuts, so I drilled the holes to 9.0mm – 9.15mm with a 23/64″ drill bit (per Threaded Inserts Guide):

Debur, smooth, clean, prime, and paint all bare metal. I had several scratches from the jigsaw, not my finest work but hey no big deal… at least I won’t do that mistake when installing the Maxfan!

Install the four M6 rivet nuts. Gasoline/diesel heaters require periodic maintenance, so using rivet nuts will allow the heater to be removed and reinstalled easily:

Rivet nuts installed! We’re getting somewhere!

We will route the harnesses under the center plastic trim and into the passenger seat pedestal like so:

First, pull up to remove the plastic trim:

Remove the two nuts with a 15mm hex socket:

Here is what you will find under:

Route the lead harness, EasyStart Pro controller harness, and fuel pump harness from the driver side to the passenger seat pedestal:

Note: I chose not to use split loom tubing because the plastic trim will encapsulate and protect the harnesses.

Make sure to route the correct extremity of the harnesses, as shown below:

Reinstall the plastic trims:

Install the heater on the mounting plate:

Close-up:

Note: Also install the heat sheath over the fuel line! (not shown below, but shown in the next photo)

Route the intake, exhaust, and fuel line through the cutout (the fuel line goes over the vehicle exhaust, towards the driver side as shown below in Fuel Supply):

NOTE: I already reinstalled the seat pedestal, but next time I would do it after I’m done installing the heater…

Secure the heater assembly with four M6 screws (as always, stainless steel):

Driving on RhinoGear Ramps MAX (16,000 lbs capacity) will make the next steps more enjoyable (always use the parking brake AND wheel chocks). If you don’t have ramps, that’s fine too, but from what we’ve seen from others, you will have to jack the van a bit to be able to slide the tank out:

Mark the fuel straps (#1, #2, #3, #4) for subsequent reinstallation (we have the 32-gallon extended-range tank, not sure if the “normal” tank has 4 straps):

Remove straps #2 and #3 with a 13mm socket and a 10in extension bar:

Place an ATV jack (or such) under the tank to assist with the removal. Here is my poor man’s Multi-Level-Fuel-Tank-Jack-2000-Station (the tank is just a big plastic box; it is not that heavy if emptied properly):

Unsnap the fuel line between straps #1 and #2:

Unsnap the fuel lines at the front of the tank. You will have to hurt SpongeBob a bit:

There are 3 fuel lines and 2 electrical plugs to disconnect on top of the sender unit. It’s not as easy as it sounds, so we will review them one-by-one:

1. Push the red tab away.
2. Push down on the grey tab.
3. Pull the connector:

1. Push down on the tab.
2. Pull the connector:

1. Push the green tab up.
2. Pull the connector.
3. Repeat for the red tab:

1. Pull the red tab up (you may have to spread the arms away and wiggle a bit).
2. Pull the connector:

This is at the front of the tank:

1. Pull the red tab.
2. Pull the connector:

Disconnect the fill hose with a 7mm socket (only if you emptied the tank first!):

Slide the tank out of the van. Sit down, relax, regroup. Be happy but don’t celebrate just yet; there is more work to do:

Remove the 3 nuts with a 10mm socket:

Remove the plastic retainer:

Use a hammer with a softer-ish material (e.g. wood) to unlock the metal lock ring:

The sender unit is free to go! Gently pull up to remove it. It’s very tight but it goes:

Angle the sender unit to clear the float through the fuel tank cutout:

There will be fuel left in the sender unit!! You can drain it by pressing the valve underneath (we know because when putting the sender on our floor, it started to drain all…)

Let’s examine this strange creature:

Another angle:

The Espar pickup standpipe will be added somewhere around here:

There is an electrical connector underneath, not much space to work with. Here’s a tip: place the standpipe’s washer on top and use a flashlight. The washer can then be “seen” from underneath. Use the washer to find the exact location of the standpipe:

Pilot the center of the hole with a 1/16″ drill bit, 1/8″, and finally with a 21/64″ drill bit. Make sure plastic doesn’t fall into the sender below, and be careful not to damage the electrical connector underneath…

Insert the standpipe. The pipe will have to be bent to clear the float (see next steps), so the location you choose now is important. The clocking I chose interfered with the plastic lock ring, but it miraculously worked by clocking it slightly counterclockwise (it was extremely tight). Below is how I would do it if I had to start over (more clearance during reinstallation later):

Clock the standpipe to its final position. Bend the pipe to clear the float. You want small, gentle bends. Too much, and the center will kink and restrict the flow! Leave the interior nylon protector during the bend operation (maybe it helps prevent kinks). Make sure the float clears the standpipe during its full travel (move the float up and down):

Insert the standpipe fully and trim it to your desired length. If the pipe goes all the way to the bottom of the tank, you may wake up one day with an empty tank… But the reason we cut it is to account for the “spring” when reinstalling the sender unit into the tank (try it: press on the top of the sender and notice how it “springs” down). If the pipe is too long, you won’t be able to reinstall it fully. So we trimmed about half an inch using a Dremel with a metal cutting disk:

Remove the nylon insert before trimming. Clear the hole after trimming (make sure it is full size and not clogged):

Insert the washer and nut:

There is no room for a wrench, so insert a long 12mm socket. Finger-tight, then add about a quarter turn (I used vise grips onto the socket for the last quarter turn):

Gently reinstall the sender unit into the tank (careful with the float and the standpipe), then reinstall the metal lock ring and plastic retainer. Remove the nylon insert if you didn’t already (in the standpipe), then install the butt joint and fuel line:

I had to relocate the fuel clamp to prevent chafing, see next photo)

Bring the tank back under the van and reconnect all the fittings on the sender, the fuel line at the front, and the fill hose. We indicated below how we would clock the standpipe if we had to start over (because the butt joint and fuel hose clamps are very tight, we got lucky that it doesn’t chafe on anything!). And at last we encapsulated the fuel line in 1/4″ split loom tubing:

Make sure to insert the connectors fully, all the way, before locking them in place!

Reinstall the fuel tank (remember to snap the fuel lines back into place). You can seize the opportunity to install the fuel pump bracket when reinstalling strap #3. Here is a photo from the future to show how it goes:

That’s it. You can pass out now.

Route the fuel line over the vehicle exhaust from the heater towards the driver side. Use a stainless steel pipe clamp to keep the Espar fuel line as far as possible from the vehicle exhaust (heat shield):

The pipe clamp is secured with a stainless steel M6 bolt. Drill a 1/4″ diameter hole (smooth, prime, and paint the edges) through the floor for the bolt:

First, remove the cap and keep it (it will be installed on the controller’s harness). Install the connector that mates with the lead harness near the heater unit. Here is the order of the components:

Crimp the connectors using pliers:

The lower wings are crimped to the wire insulation to prevent pullout:

Push each wire firmly into the connector in order to match the colors:

Gently insert the orange thingy:

Here is how it looks inside:

On the other end of the harness, connect the EasyStart Pro connector AND the cap that was previously removed from the lead harness:

Note: This cap contains a resistor and must be installed!

How you route the harness depends on your layout/installation. We are just starting our conversion at this time, so we designed and 3D printed a temporary control panel to house the EasyStart Pro controller:

First, install the fuel pump connector that mates with the lead harness near the heater unit. Here is the order of the components:

Slide the rubber seals over the wires and crimp the connectors using pliers:

Insert the two wires into the connector:

Final result. You can now connect the fuel pump connector to the lead harness:

The routing of the fuel pump harness depends on your installation. In our van, we routed the harness through the floor via the pass-through hole that we created in the wall behind the driver seat:

The harness is then routed to the fuel pump. Use split loom tubing to protect the harness and secure it with zip ties:

At last, plug the harness into the fuel pump (the connector is already pre-installed):

The power cables are at the far end of the lead harness (away from the heater unit). Most people, including us, connect these wires to their house battery bank (aka auxiliary system) via the fuse block. In this case, there is no need to use the inline fuse included in the Espar kit.

We still haven’t built our electrical system… so for now, we will temporarily use the vehicle’s electrical system to power the Espar. Therefore, we need to use the inline fuse included with the kit as follows:

We are using the CCP2 (on the driver seat pedestal), which is capable of providing 12V power up to 175A, and is always hot (unless the power-saving function of the vehicle kicks in! In this case, it may cut power when the van is parked):

NOTE: Remove the fuse from the fuse holder when making the connection! Insert it after your installation is final.

For the negative connection, we are temporarily using the BEMM recommended ground point between the passenger and driver seat:

Reinstall the passenger seat pedestal and connect the hot air flexible pipe from the heater to the connection socket:

Note: The pipe is very rigid; it is quite difficult to make it fit… but it does fit with a bit of perseverance and patience!

Same same but side view:

Note: There is about an inch of clearance between the pedestal and the heater’s intake (front), even if the photo makes it look like less!

To access the workshop menu on the EasyStart Pro: enter the settings menu, then press the back button for more than 2 seconds:

You’re in!

1. Power the Espar system by inserting the inline fuse, or by inserting the fuse into your fuse block:

NOTE: Make sure to use the correct fuse. The EsparParts kit includes a 20A fuse for 12V systems, and a 15A fuse for 24V systems.

2. Follow the prompts on the EasyStart Pro controller: language, 12h/24h, time, day, units, etc:

Note: The “Control Sensor” prompt allows to read and control the temperature from the sensor located in the heater itself (“Air Heater”) or use the sensor inside the EasyStart Pro controller (“Control Unit”). We recommend the latter, because the temperature near the heater (e.g. under passenger seat) is generally not representative of the living space temperature.

3. Make sure you have enough gas in the tank. Otherwise, the pump will suck air, not gas! (yep, that’s a very common mistake):

4. Set the heater to the maximum temperature (to make sure that it starts and runs for the whole test):

5. The fan should slowly ramp up. Here we go! After a few seconds, the fuel pump will start ticking. At this point, go to the fuel pump and check that the fuel line is priming (fuel is coming out of the fuel tank, through the pump, and slowly making its way toward the heater).

Note: Because it’s the very first start and the fuel line is empty, it may take a second startup attempt for the fuel to reach the heater. No worries, this is normal! Access the Workshop menu and clear the error code and start the heater again (as required):

Note: Bubbles in the fuel line are an indication that some joints were not properly made. In this case, make sure that the fuel lines are fully inserted in the butt joints and that the “wings” of the fuel hose clamps are touching (the screw is fully tightened).

6. Success? Don’t turn off the heater just yet! Remember:

• Short cycles are not ideal for carbon buildup. Always run the heater for at least 10 minutes, so that it reaches a high temperature.
• It’s good practice to run the heater at maximum intensity for 10 minutes before shutting it off. It helps keep it clean and prevents carbon buildup.

7. Always shut down the heater with the EasyStart Pro controller. Do not just cut electrical power; the heater needs to complete its shut-down procedure (i.e., evacuate residual fuel and heat to prevent overheating and damage):