Campervan Heating Systems.

The 30-Second Answer.

If you just want heat and want to keep it simple, a diesel air heater like the CaveWave is hard to beat — it taps your van's existing fuel tank, the new units have an intuitive hibernation mode, and they pair with 12V AC right from an app.

If you want an interior shower, radiant floor heat, or you hate the dry, forced-hot-air feeling, a hydronic system is the better call because it gives you instant hot water and gentle radiator heat instead of blowing air.

Most of our customers land on one of those two paths — and which is "right" comes down to whether you want hot water and how you actually live in the van, not which one is "better." Here's the honest version, from a shop that installs and repairs basically every brand on the market.

Two Paths: Forced Hot Air vs Hydronic.

There are really two families of van heat, and almost every decision flows from which one you pick.

Forced Hot Air (diesel or gas air heaters)

These burn a small amount of fuel from your van's tank, heat a metal exchanger, and blow warm air into the cabin. Simple, fuel-sipping, fast to warm up, and far more affordable. The tradeoff: it's forced air — if you have allergies or don't like the dried-out feeling that comes with blown heat, this can bother you. CaveWave, Autoterm, Webasto, Espar (Eberspächer), Rixen, and the cheap Chinese units all live here.

Hydronic

Instead of blowing air, a hydronic system heats fluid and circulates it — gentle radiator "kick" heaters mounted on the side of cabinets warm the space, and the same system gives you instant hot water for an interior shower. If you want a real interior shower, radiant floor heat, or that even, non-drying warmth, this is the path. The catch is cost — a hydronic system is a significant step up over a fuel-based forced-hot-air unit.

And here's where it gets interesting: once you have a dedicated interior shower running off instant hot water, you can add our Infinity Shower — a recirculating system that runs your shower water through a UV sterilizer and micron filter, reheats it, and sends it back to the head. Less than a gallon recirculates the whole time, so you can take an hour-long hot shower on a 20-gallon tank without rationing. It's a +$8,500 upgrade over the dedicated interior shower (which it requires), and for full-timers it solves the water-anxiety problem the same way a big lithium bank solves power anxiety. The hydronic system is what makes that endless hot water possible.

What About Hot Water Without Going Full Hydronic?

This is the middle path a lot of people miss. If you want forced hot air and some hot water — but don't want to pay for a full hydronic system — you can pair a diesel air heater with a small 120V mini hot water heater (about 1.6 gallons). It's a basic, cost-effective setup that gives you hot water at the sink and a quick warm shower in the rear. It's not the "have it all" system, but it's a great option for someone who doesn't need everything.

For what it's worth: I run an interior diesel heater in my own van. I don't have an interior shower I use in the summer season, so I don't need instant hot water — and I don't mind what I have. The point isn't that one system wins. It's matching the system to how you actually travel.

Your Chassis Changes the Install (and the Cost).

Here's something most buyers don't know until the quote comes back: the van you choose affects what your heater costs to install. Diesel and gas air heaters tap into your van's fuel tank through an accessory fuel port.

On a Sprinter or ProMaster, that port is easy to access — it's a clean, straightforward install. On a Transit, it's a much bigger job: you often have to fully drop the fuel tank to make the connection. Same heater, very different labor.

So if you're cross-shopping chassis and planning a fuel-tapped heater, factor that in. It's not a reason to rule out a Transit — but it's a real line item, and you should know about it before you're surprised by it. It's the kind of detail we walk through when we spec a Scout or a Loft on your chosen platform.

The Altitude Filter: Ask This Before You Buy Anything.

If there's one thing in this whole guide that will save you the most grief, it's this: most diesel heaters are tested and rated for lower elevations. They work great down low. Take them up high, into thin air and deep cold, and a lot of them struggle — harder starts, more carbon soot, unreliable performance exactly when you need heat most.

Here's the problem: manufacturers don't always tell you the altitude ceiling clearly. So the single most important question to ask before you buy any heater is: "What elevation is this rated and tested to perform at?" If the company can't give you a straight answer, that is your answer — assume it's a low-elevation unit and move on.

This matters because your plans should drive the decision. If you're a serious skier or you chase the high country in winter, a big chunk of what's on the market should come off your list immediately — not because those units are bad, but because they weren't built for where you're going. You need a system proven at the highest elevations in the lowest temperatures. Everyone else — weekenders, fair-weather travelers, lower-elevation trips — has far more options.

In our experience, the systems that genuinely perform in demanding high-elevation, low-temp conditions are Velit, CaveWave, Aqua-Hot, and Rixen. The CaveWave units, for example, use barometer-based adjustment to tune the air-fuel mix automatically up to around 16,000 feet, which both keeps it running reliably and minimizes the carbon buildup that causes most cold-weather failures. That's not a luxury feature for a high-altitude traveler — it's the whole ballgame.

The Reliability Truth.

The number one thing customers worry about is a heater dying on the road in the cold. Here's the honest truth from our service bay: they all need maintenance, and the more intuitive and feature-packed the unit, the more maintenance it tends to need. There's no magic box you install and forget.

What actually needs attention, across the diesel air heaters:

• Run it hot, regularly. Running the heater on high for 30+ minutes periodically burns off carbon soot before it hardens on the burner mesh; short-cycling a too-big heater in a small van is how you clog a burner in weeks.
• Run it in the off-season too. Even when you're not using it for heat, run the unit ~20–30 minutes every 4–6 weeks to keep the fuel pump's bellows lubricated and burn off deposits; the better modern units (like CaveWave) will actually remind you to do this from the app.
• The burner chamber and glow pin/screen carbon up over time. That's the routine service: clear the soot, replace the screen, gaskets, and inline fuel filter, roughly annually or every ~500 hours depending on use.
• Fuel, intake, and exhaust get inspected seasonally.
• Altitude makes it worse. More carbon builds up at elevation, so high-country travelers need to run hot more often and want a unit that auto-tunes for altitude.

Our Honest Brand Experience.

We've installed and serviced just about everything, and our decisions come down to three things: sizing, maintenance, and customer-service infrastructure.

We started where a lot of people start — the cheap Chinese diesel heaters. They're everywhere and tempting on price. The problem is what happens when something goes wrong: no real customer service, instructions barely in English, parts and support that leave you stranded. They can work — but you're on your own.

The Euro and US heaters (Webasto, Espar/Eberspächer, Velit, Rixen, Timberline, Autoterm) are a different tier — better build, real support networks, fault-code diagnostics. We work on all of them. Webasto in particular is regarded as one of the most robust air heaters out there — essentially no moving parts except the fan, with combustion-chamber carbon being the main long-term wear item.

CaveWave is where we point a lot of "I just want heat" customers right now — intuitive hibernation mode, connects to their 12V AC units in one app (Bluetooth up to ~100 ft, multiple units in one app), built-in gas safety sensors, and barometric high-altitude tuning to ~16,000 ft. On high-elevation performance specifically, the systems we've had great experience with are Velit, CaveWave, Aqua-Hot, and Rixen.

Aqua-Hot has been our hydronic workhorse, but honestly we've been having issues with them lately, and we're looking hard at Rixen as where we're heading on the hydronic side. On water heaters: we've used the Duetto 12V (works great, but super big), the Whale 12V (worked pretty well), and there's Isotherm plus others. Lots of options — which is exactly why this decision is worth thinking through.

The Warranty Trap Nobody Warns You About.

Here's the one I really want you to hear, because it costs people whole seasons. Even a heater with a great warranty can still have issues — and getting it serviced can be a pain.

If you pick a heater that's widely used on mainstream campers, the company will proudly tell you it can be serviced at dealerships all over the country. That sounds great, and it does add to that brand's network. But here's the catch: those dealership service centers are always slammed. It can take you six months to get heater work done at a dealership. A great warranty doesn't help much if you can't get in the door until spring.

When we evaluate a brand, "how hard is it to actually get this serviced" weighs as heavily as the spec sheet.

So Which One Should You Get?

If you're new to the heater game, read this twice.

• Just want heat, keep it simple, modern features: a diesel air heater (we like CaveWave right now) — easy install on Sprinter/ProMaster, bigger job on Transit.
• Want an interior shower, radiant floor, or hate dry forced air: hydronic — instant hot water, gentle radiator heat, at a real step up in cost.
• Want hot water without the full hydronic price: diesel air heater + a 1.6-gallon 120V mini water heater — hot water at the sink, quick warm rear shower, much more affordable.

There's no universally "best" heater — there's the right heater for your application. Our advice is built from real installs and real repairs across every brand, and we're happy to talk through what fits how you actually travel.