RV water heaters come in various types, including diesel, gasoline, propane, electric, or tankless models. Hot water systems have a lot of essential components, from heating elements and thermostats to anodes and exhaust systems.

Comfort on the road is extremely important, and two most trusted names in the automotive heating industry are Webasto and Espar (Eberspacher). How to know which one is the best for you?

This in-depth guide compares these industry giants, with real-world feedback, expert opinions, and side-by-side evaluations to help you choose the right one.

Webasto is a well-known manufacturer, based in Stockdorf, Germany. Founded in 1901, the company provides heating, cooling, and solar technology to the automotive sector.

Webasto has built a reputation for offering compact and reliable air heaters that work exceptionally well in vehicles like camper vans and trucks. Their systems are especially appreciated for their fuel efficiency and availability of spare parts.

On the other hand, Espar, a subsidiary of Eberspächer, is another German engineering titan. Founded in 1865, Eberspächer has a long history of innovation in climate solutions, including hydrogen initiatives.

Espar products are highly valued for their high-altitude capabilities, quiet operation, and easy integration into more complex van conversions.

While both companies produce exceptional heating solutions, their design philosophies differ slightly. Webasto focuses on simplicity and economy, while Espar prioritizes performance, especially in harsh or high-altitude environments.

When choosing a heater model, it’s important to understand the differences between diesel and petrol heaters. Each has its own pros and cons depending on your travel style and vehicle type.

Diesel heaters are typically preferred for full-time travelers using vehicles powered by diesel. These units are more efficient in colder weather and consume less fuel per hour.

They’re also more popular in larger rigs and marine applications. However, diesel heaters are slightly more expensive and require more effort during installation.

Petrol (gasoline) heaters are ideal for vehicles running on petrol, as they avoid the need for an auxiliary fuel tank. They’re easier to install and slightly cheaper, though they may release more odor during operation and can be less efficient at high altitudes.

As a rule of thumb, match your heater's fuel type to your vehicle's fuel type for easier installation and refueling.

Webasto's Air Top 2000 STC is one of the most widely used gasoline heaters in the van life community. The Webasto Air Top is a series of exceptionally energy efficient heaters, with a heat output ranging between 2 and 5,5KW.

With a compact 2kW heat output, it’s ideal for small to medium-sized vans. Fuel efficiency and space-saving installation options make this system great - it can be mounted either externally or under a seat. Air top heaters can only be mounted externally if boxed in a protective cover box.

Altitude performance, however, is limited. This heater works well up to 1,500 meters (around 5,000 feet), which might not be enough for mountain explorers. It supports multi-controllers, allowing users to efficiently read the temperature in the cabin.

The Espar AM3 B4L  on the other hand, delivers a powerful 4kW of heat - double that of the Webasto STC. This model is designed for high-altitude use, capable of operating at elevations up to 5,500 meters (almost 18,000 feet). That makes it ideal for exploring high-altitude national parks in the USA.

With automatic temperature control and an improved burner, it will quickly and quietly warm your cabin to the right temperature. It includes a fuel line and a 12V fuel pump that allows the heater to be connected directly to the vehicle's fuel tank.

The heater pairs with the EasyStart Pro controller, which displays fault codes, controls temperature precisely, and even has scheduling functionality.

If budget is your primary concern, Webasto is a smart and reliable choice for most vehicles. Due to its small size and great fuel and power efficiency, you'll stay warm without breaking the bank.

However, if you plan to go into colder and higher areas frequently, Espar’s B4L will give you better performance. It generates twice as much heat as the Air Top and can handle high altitudes, making it ideal for larger automotive applications.

It's also a better choice for DIY installations, thanks to its plug-and-play feature that requires fewer tools and no wires to crimp.

The diesel variant of the Webasto Air Top 2000 STC shares most of the same features as its petrol alternative, but with improved fuel efficiency - ranging between 0.12 to 0.27 liters per hour. This makes it a great option for long-term travel and off-grid setups.

Its compact size and wide range of aftermarket parts make it one of the most DIY-friendly diesel heaters around.

Espar’s D2L model is the updated version of the much-loved Airtronic D2. With 2kW power, it’s great for small to medium vehicles. It’s designed for ultra-quiet operation, automatic temperature control, and can be used at altitudes up to 10,000 feet without modification.

It also has a ventilation mode that circulates cool air in warmer months. Combined with its diagnostic capabilities and long product life, it’s one of the most premium diesel heaters on the market.

When it comes to diesel heaters, Webasto and Espar both offer top of the line options. Webasto has more affordable diesel heaters better fit for regular use at lower altitudes. Adjusting the Air Top 2000 STC to high altitudes is known to be challenging, but that's balanced out by its record breaking fuel efficiency.

With the release of their newest 3rd generation Airtronic heaters, Espar has definitely outperformed all its competitors, at least for the time being.

The newest AS3 D2L and AM3 D4L are several times quieter than their Webasto competitors, more fuel-efficient, heat the room faster, and can reach high altitudes. All of that comes with a premium price, which in our opinion is well worth it.

Installation varies between the two brands. Webasto heaters often require connecting wires and following in-depth instructions, though plenty of tutorials and third-party kits are readily available. Espar, on the other hand, makes it easy to use with plug-and-play options and clearly labeled parts.

Maintenance is similar for both. Glow plugs, combustion chambers, and fuel lines should be cleaned or replaced every couple of seasons. Webasto heaters may have more accessible spare parts due to a larger distribution.

In terms of control, Webasto's MultiController gets the job done but lacks the diagnostic features of Espar’s EasyStart Pro, which gives users a better experience with onboard error readouts and scheduling.

Both Webasto and Espar provide high-quality, reliable heating solutions. Your decision should reflect your travel style, climate, and budget.

Choose Webasto if:

• You have a limited budget.
• You plan to install it yourself with online guides.
• You're traveling at moderate altitudes.
• You want reliable heating with a low fuel consumption.

Choose Espar if:

• You frequently stay at high elevations.
• You prefer quieter operation and modern controllers.
• You need faster cabin heat-up times.
• You're okay with spending more for comfort and ease.

No matter which brand you go with, a quality heater can transform your lifestyle. From weekend getaways to full-time van life, both Webasto and Espar keep you comfortable when you need it most.

Still unsure? Send us a message - we’re here to help you stay warm wherever the road leads.

Yes. Many DIYers install these heaters successfully with online tutorials, but a professional install can guarantee better reliability and safety.

Absolutely. Both Espar and Webasto heaters are designed to operate while the vehicle is in motion.

If you're consistently travelling above 1,500m (5,000 ft), yes. Espar handles this better out of the box, but Webasto needs a kit.

Technically yes, but you’ll need to add a separate diesel tank. For best results, it is advisable to match your vehicle’s fuel type with the heater.