Espar Airtronic AS3 D2L 12V Diesel Heater - Full Kit

The classic diesel van heater, complete: 7,500 BTU from the fuel already in your tank, with a genuine Eberspächer harness and the Easy Start Pro controller.

The Espar Airtronic AS3 D2L is the heater most professionally built diesel vans in North America end up with, and the reasoning has not changed in twenty years. It burns fuel from the van’s main diesel tank, so there is nothing extra to carry. It draws 4–27 W while running, so it will heat a van all night without meaningfully touching a house battery. And it puts out 7,500 BTU (2.2 kW), which is enough for an insulated van in genuinely cold weather.

This is the full kit — heater, install kit including the fuel standpipe, Easy Start Pro controller, muffler, clamps and exhaust bracket — built around a genuine Eberspächer unit with an Eberspächer harness.

Diesel or gasoline — and will it fit your van?

• Buy the D2L (diesel) if your van runs on diesel — a 2007+ Sprinter, a diesel ProMaster.
• Buy the B2L (gasoline) if your van is gasoline.
• Ford Transit owners: read the fitment note. There is no Espar diesel Transit kit offered at this time.
• Consult a licensed builder or mechanic before installing on a diesel model — the manufacturer recommends it, and so do we.

Vehicle fitment and fuel pickup

These full kits are designed for 2007+ Mercedes Sprinter, 2014+ Ram ProMaster and 2015+ Ford Transit vans. The fuel pickup is where the platforms differ, and it is the part of the job that decides your weekend — read the fitment table before you order.

Specifications

Complete documentation is available — install instructions, operating instructions, technical sheet, troubleshooting guide, spare parts list, repair instructions, plus the Easy Start Pro controller guides and wiring diagram. Ask us for it before ordering if you want to plan the install first.

Package contents

• Espar AS3 D2L 12V heater (diesel)
• Install kit — AIR S3 D2L 12V, including the fuel standpipe
• Control kit — Easy Start Pro controller with adaptor
• Exhaust muffler, 24 mm
• Muffler clamps, 26–28 mm (2)
• Exhaust bracket

Installing it: the fuel pickup is the job

The heater mounts in an afternoon. The fuel pickup decides the rest. On a Sprinter or a ProMaster there is a factory auxiliary port and the supplied hoses clamp straight to it, which is why those two platforms account for most successful DIY installs.

The exhaust is the part people underestimate. It runs hot, it has to be supported so it cannot vibrate against the body, and where it terminates matters — not near a door, not near a window, not where you sit outside with the doors open.

• Fuse and wire for the ~30 A glow plug startup draw.
• Insulation wrap on exterior fuel lines and connections — recommended, not supplied.
• The muffler can face either way; the routing and support are what matter.
• Terminate the exhaust away from doors, windows and your outdoor living space.
• Consult a licensed builder or mechanic before installing on a diesel model.

Questions we get asked about this part

Are these genuine Eberspächer units?

Yes. Not all Espar kits on the market are built the same. These are genuine Eberspächer heaters supplied with high-quality Eberspächer wiring harnesses, rather than a genuine heater bundled with a generic harness.

Will it flatten my batteries?

Running, no — rated power consumption is a handful of watts, which is nothing next to a compressor fridge. Starting, briefly yes: the glow plugs draw roughly 30 A at startup for the first minute or two. Size your wiring and your fuse for the startup draw, not the running draw. That is the single most common electrical mistake on these installs.

How high can I take it?

The kit includes an altitude sensor and the heater is rated for automatic altitude compensation up to 13,120 ft (4,000 m). That covers every paved pass in the continental United States. Without altitude compensation, a fuel-burning heater runs rich at elevation and sooties itself up.

Which way round does the muffler go?

The included muffler does not mark a flow direction. Espar have confirmed it can be mounted in either orientation. What does matter is following the installation guidelines for undercarriage mounting — getting the exhaust routed, supported and terminated correctly is more important than the muffler’s rotation.

Can I fit this to a Ford Transit?

Not with this kit as supplied. A Transit install would require dropping the fuel tank and adding a fuel pickup pipe and components, and an Espar diesel Transit kit option is not offered at this time. If you have a gasoline Transit, look at the AS3 B2L instead.

What is the difference between the D2L and the B2L?

Fuel. The D2L is diesel and produces 7,500 BTU at 4–27 W. The B2L is gasoline and produces 6,824 BTU at 11–26 W. Both share the same physical dimensions, the same 5.5 lb weight, the same 13,120 ft altitude compensation and the same Easy Start Pro controller.

Pairs well with

• Van heating, ventilation and conversion parts

Sold and shipped by Campervan Parts R Us, the parts counter of Noke Van Co. — a working van conversion shop in Roanoke, Virginia. If you are unsure whether this fits your van, email us the year, model and wheelbase and we will check it against a build sheet before you order.