After more than 10 years building high-end campervans through Vanlife Conversions, we've installed our fair share of diesel heaters. Some have been fantastic, while others have taught us a few expensive lessons!

We've worked with Webasto, Autoterm and the budget-friendly Vevor heaters, so when we installed the HLN Aerolyn 4000 in my own Fiat Ducato, I was keen to see how it compared.

And so far, it's been a pleasant surprise.

Not All Diesel Heaters Are Created Equal

We've installed two Vevor 2kW heaters for customers looking to keep their conversion costs down. Unfortunately, both ended up being replaced under warranty, at our own labour expense.

We found the controllers cheaply made, the buttons prone to jamming and the heaters noisier than their more expensive counterparts. We also experienced soot buildup and reliability issues. Needless to say, we won't be installing them again.

On the other hand, we've had good experiences with both Webasto and Autoterm.

Webasto sits at the premium end of the market, with excellent build quality and technical support, something we really value as professional installers. Autoterm is another solid option, generally a little more affordable, although we've found technical support less accessible.

So where does HLN fit in?

The HLN Aerolyn 4000

At $699 AUD for the complete kit, including your choice of WiFi or Bluetooth ComfortStart controller, the Aerolyn 4000 sits at a very attractive price point.

The heater itself presents well. It's compact, feels solid and is similar in size to other units we've installed.

HLN has been manufacturing diesel heating systems for more than 50 years and supplies equipment to major vehicle manufacturers. According to HLN, the company has also had a historical manufacturing relationship with Webasto.

That's reassuring background for a brand entering the Australian campervan market.

The Controller Is a Standout

One of my favourite things about this heater is the ComfortStart controller.

It's clear, intuitive and doesn't feel like an afterthought. You can choose between manual heating, automatic thermostat control or ventilation-only mode for warmer weather.

There are six programmable timers, on-screen diagnostics and the option to control the heater from your phone. The Bluetooth version works without internet, which is particularly handy when you're camping somewhere with no reception.

The heater also has a clever shutdown process. When switched off, it runs a carbon burn-off cycle before completing its cool-down, helping reduce soot buildup in the combustion chamber.

The fan continues running for around three minutes after the fuel pump stops, so it's important never to disconnect the main power during shutdown.

It's these little details that make a difference over time.

Performance in the Ducato

We've installed the Aerolyn 4000 in my Fiat Ducato, and it's been doing a wonderful job of keeping the space warm.

Despite the 4000 name, the heater has an adjustable output of 1.0–3.5kW, with diesel consumption ranging from approximately 0.12 to 0.43 litres per hour.

The thermostat makes it easy to maintain a comfortable temperature without constantly fiddling with settings.

It also features automatic altitude compensation, with a built-in pressure sensor adjusting the fuel-to-air ratio at higher elevations. HLN rates the unit to 5,000 metres, although we haven't personally tested that capability.

For Australian alpine trips, it's a useful feature to have.

A Few Installation Considerations

The Aerolyn 4000 is available in 12V and 24V versions and comes with a full installation kit.

Like any diesel heater, correct installation is essential. You'll need to consider the mounting position, combustion air intake, exhaust routing, electrical supply and fuel connections.

The heater can be supplied from a separate diesel tank or connected to the vehicle's existing fuel supply, using an appropriate pickup that preserves enough fuel to drive.

Always maintain the manufacturer's required clearances around the heater and ducting, and never allow clothing, bedding or stored items to obstruct airflow.

While experienced DIYers may be comfortable tackling an installation, we'd recommend professional fitting, particularly when dealing with fuel systems and combustion exhaust.

A properly installed carbon monoxide alarm is also essential.

The Verdict

For $699, the HLN Aerolyn 4000 offers a lot.

The build quality feels good, the ComfortStart controller is excellent, and the heating performance in our Ducato has been impressive.

The kit also comes with a two-year parts warranty, although installation labour isn't covered.

Of course, this is the first HLN heater we've installed, so we're not going to claim years of proven reliability just yet. That's something only time will tell.

But based on our experience so far, it's a promising alternative to both the cheaper budget heaters and the more expensive established brands.

Would we install another one? Absolutely, based on what we've seen so far.

And after the lessons we've learnt with some of the cheaper heaters, that's not something we say lightly.

About Vanlife Conversions

We're a campervan conversion business with workshops in Newcastle, NSW, and Torquay, Victoria. With more than a decade of experience building high-end campervans, we specialise in complete conversions, electrical systems, heating and upgrades.

We also offer professional diesel heater installations at both locations.

Disclosure: This review is part of a paid collaboration with HLN Heaters. The Aerolyn 4000 was installed in my own Fiat Ducato, and the opinions shared are based on our hands-on experience.

By Jared Campbell | Vanlife Conversions

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