Which diesel night heater to fit in a campervan (VW Transporter T5/T6 routing)

The Problem

The van owner wanted to fit a diesel night heater but was undecided between well-known brands like Eberspacher and Webasto and cheaper Chinese alternatives. The van — a VW Transporter T5/T6 — was already insulated with a rib bed fitted, but no heater had been installed yet.

Solution

1. Choose an AutoTerm Planar 2D (2kW, 12V) heater with a comfort or afterburner controller as a cheaper proven alternative to Webasto or Eberspacher. The AutoTerm model designation is Planar 2D-12 (verify part number before ordering, as kit/controller bundles vary).

   • Budget alternatives such as the Lavaner Pro or HLN diesel heaters were also recommended at around £180 delivered (verify exact model/part numbers before ordering — fit and compatibility vary across these unbranded variants).

2. Route the ducting through the original B pillar ductwork and feed the electrics down through the original grommet under the right-hand seat. These routing points are specific to the VW Transporter T5/T6 — if you have a different van, identify the equivalent factory ducting and cable runs for your model.

3. Wire the heater to the fuse box under the passenger seat (again, T5/T6-specific). These heaters draw a high current during glow-plug start-up — roughly 8–10A on a 2kW 12V unit. Use the heater's supplied power loom wherever possible. If you need to extend it, run a minimum 4mm² cable on a dedicated supply protected by a 15A fuse. Confirm the exact cable gauge and fuse rating against your heater's installation manual before wiring, as it is a safety-critical detail.

4. Mount the air intake in the step and ensure the seal is tight to prevent exhaust fumes from recirculating into the van.

5. Once installed, tune the air–fuel ratio (AFR) using the controller: run the heater at full output and reduce the fuel rate (Hz) gradually until the heat-exchanger body temperature — as shown on the controller display readout — begins to drop.

   • Allow 5 minutes between each adjustment. The sweet spot is around 200–210°C at maximum output (controller-displayed body temperature).

6. Fit a carbon monoxide alarm low down in the van, as CO and other heavy gases accumulate at floor level.