HowTo ·

The Professional Finish: Installing Your AVC Espar Heater Trim Unit

Hey everybody, Matt here for AVC and welcome back to the blog!

We've been working closely with Espar to ensure their D2L/S2D2L furnaces are properly integrated into the Ford Transit platform. To further this integration, we developed this custom AVC Espar Trim Unit. This unit ensures proper duct alignment, a superior fit with the Ford Transit seat base, and a professional, finished appearance.

Whether you're a DIY-er or a professional installer, this trim unit is designed to give your heater better performance and a clean look.

Key Features of the AVC Trim Unit

The unit is designed to utilize existing factory features for a flawless installation:

  • Factory Alignment: The three holes on top align perfectly with the factory mounting holes on your Transit seat base.

  • Duct Alignment: The mounting point for the ducting register aligns precisely with a correctly placed Espar furnace.

  • Customizable Plug: The small tree logo on the bottom right can be twisted out and replaced with a 12V or USB charging plug.

Now, let’s get to work!

Step 1: Remove the Seat and Inverter

To gain clear access to the seat base, you need to remove the passenger seat and the factory inverter.

  1. Remove Seat: Use a 10mm socket to remove the four bolts securing the seat to the base. Use a 7mm socket to disconnect the wiring harnesses underneath the seat. Optional: Remove the seat belt attachment (T50 Torx) to completely clear the work area.

  2. Remove Inverter: The Ford Transit often comes with a 400-watt square wave inverter inside the seat base. We recommend removing this.

    • Use a deep well 10mm socket to remove the three bolts securing it.

    • Disconnect the wiring and set the unit aside.

  3. Remove Seat Base: Use a 15mm socket and a long extension to remove the four main bolts securing the seat base to the floor of the van.

  4. Disconnect Wiring: Use a panel popper tool and your fingers to pop off any remaining wiring harness connections secured to the base.

Step 2: Modify the Seat Base

The stock seat base has several components that must be removed or cut to allow the furnace and ducting to pass through.

  1. Cut the Hoop: Use an angle grinder to cut off the large metal hoop at the very top of the seat base.

  2. Mark the Ducting Area: Dry-fit the seat base back into the van and place the AVC trim unit over the mounting holes. Use a marker to trace the area where the ducting will exit, ensuring you flare the lines out slightly to give the duct plenty of room.

  3. Mark the Heater Placement: Use the AVC template to mark the consistent placement of the Espar unit on the van floor, centered over the factory bolts.

  4. Cut the Floor Bolts: Use a vibrating saw (multi-tool) to cut the two bolts securing the old inverter flat to the floor. Avoid cutoff discs or flap wheels inside the van to minimize sparks and potential rust.

Step 3: Cut the Base for Ducting Access

With the seat base back on the bench, use your markings to cut the necessary openings.

  1. Define the Cut: Connect your marks to form a large, diagonally-shaped opening at the back of the seat base. This provides room for the ducting and tool access.

  2. Critical Integrity: DO NOT cut into the following areas:

    • Any factory welds securing the seat base together.

    • The rolled (bent) metal edge around the bottom, as this provides crucial structure and strength.

  3. Cut and Prep: Use an angle grinder to cut out the marked section. Paint all raw metal edges immediately to prevent rust.

Step 4: Assemble the Trim Unit

The final installation steps are done outside the van for easy access.

  1. Install the Register: Place the Espar ducting register onto the back of the AVC trim unit, aligning the three pilot holes. Secure it using three self-tapping screws (a wood screw will also work in the aluminum).

  2. Attach Ducting: Install the 60mm heater ducting onto the register and secure it tightly with the provided clamp.

  3. Install the Grille: Snap the grille onto the front. We recommend orienting the grille to blow the hot air upwards rather than forcing it down onto the floor.

⚡️ Optional: Add a Charging Port

To install a charging plug in place of the logo:

  1. Remove Logo: Take the trim unit and twist the small tree logo back and forth until the connecting aluminum tabs fatigue and break, allowing the logo to pop out.

  2. Install Plug: Slide your 12V or USB outlet into the opening and secure it with its locking nut on the back.

Step 5: Final Installation

  1. Attach Trim to Base: Place the AVC trim unit onto the modified seat base. Use the included stainless hardware: thread the large washer and stainless Allen bolts through the top, and secure them underneath with the small washer and a 5mm Nylock nut.

  2. Reinstall Heater: At this stage, you would typically install your Espar unit (a separate process) on the floor over your template marks.

  3. Reinstall Seat Base: Bolt the modified seat base, with the attached trim unit, back into the van floor.

  4. Reinstall Seat: Reconnect the wiring and bolt the passenger seat back onto the base.

The AVC trim unit integrates perfectly with the floor system and provides a clean, professional finish for your Espar heater installation.

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