Espar Heater Installation

Installing an Espar D2 diesel heater in a 2014 Sprinter van

The Espar diesel heater I installed does what it’s made to do: it blows very hot air into my van and keeps things toasty and cozy. The Espar heater installation instructions, on the other hand, are frustrating and intimidating. Having reached the happy and unexpected outcome of a working heater, I decided to document my process to help others with this daunting task. I’m a neuroscientist, not an electrical engineer, but I do have heat in my van, so take that as you will.

I bought the Espar S2-D2L heater, specifically the Sprinter package. I installed it in my 2014 144" Sprinter under the passenger seat. Here’s how.

Big Picture

Diesel heaters are relatively simple contraptions. Diesel fuel gets pumped from your vehicle’s fuel tank to the heater. This fuel is combusted to heat coils over which air is blown, heating your space.

One technical point that is helpful to understand is the two separate air paths. The air that heats your space is entirely internal to your van: it gets sucked into and blown out of the heater from the two large ports on either side of the device. Combustion also requires air, but this air is entirely external to your van: it comes from the intake and exhaust pipes you will install below your van. This is because the exhaust air contains water vapor and unpleasant diesel fumes, neither of which you want in your space. In fact, some cheaper…