How to fit an Eberspacher D2 heater in a VW T6

The Problem

The installer found the hard plastic factory plug under the driver's seat could not be resealed around the heater wiring after being drilled through, and the blue fuel tube was almost impossible to push fully home into the heater and pump bodies. No prior fix had been attempted for either issue as both were discovered mid-installation.

Solution

1. Raise the van on timber blocks and remove the plastic under-body panels on both sides to expose the chassis.
2. Locate the factory rivnut positions under the driver's seat area, fit two M6 rivnuts, and test-fit the heater bracket using stainless steel fixings throughout to prevent corrosion.
3. Attach the heater bracket to the heater body, fit the flexi pipe on the high-pressure side, then bolt the whole assembly up to the chassis rivnuts.
4. Route the high-pressure fuel line using rubber-lined P clips clipped into factory holes, following existing clip positions toward the fuel tank.
5. Mount the fuel pump using an existing hex-shaped hole in the chassis at approximately exhaust level on the driver's side; lightly file the hole, tap in a 6mm rivnut, then apply the rivnut gun.
   • The pump can sit at any convenient point: Eberspacher spec allows up to 5 m from tank to pump and up to 6 m from pump to heater.
6. Route fuel lines with a general upward slope on the delivery side from pump to heater; a slight downslope on the intake side from tank to pump is acceptable, but avoid downward loops on the delivery side where air bubbles can accumulate.
7. To bring wiring into the cab, pull out the hard plastic factory plug from the grommet hole under the driver's seat and replace it with a correctly sized rubber grommet that seals around the cable.
8. To insert the blue fuel tube fully into the pump or heater body, knead the rubber collar with pliers to soften it, then apply a drop of diesel or light oil as lubricant before pushing the tube home.
9. Wrap the exhaust outlet pipe in fiberglass sleeve or heat-wrap tape for thermal insulation.

Safety Notes

• Fuel line push-fit connections not fully seated can drip diesel onto hot exhaust components; confirm every connection is fully home before running the heater for the first time.
• Never work under a vehicle supported only by a hydraulic jack; use rated timber blocks or axle stands before going underneath.