Webasto Air Top Pro 25 Diesel 12V Heater Kit with Controller

Quiet 12V Diesel Parking Heater for Camper Vans, RVs, and Truck Sleepers

The Webasto Air Top Pro 25 Diesel 12V Heater Kit with Controller gives diesel-powered camper vans, work vehicles and truck sleeper cabs dependable cabin heat while parked. Its stepless 2,400–7,000 BTU/h (0.7–2.0 kW) output is designed for comfortable overnight temperatures, while the 8,500 BTU/h (2.5 kW) boost mode helps warm a cold interior quickly. Choose a factory kit with a Rheostat Controller (5014433A) or Webasto MultiControl (5014494A).

Benefits & Everyday Use

• Steady overnight comfort: Continuous heat modulation down to 0.7 kW reduces the need for frequent restarts in milder conditions.
• Fast cold-weather warm-up: 8,500 BTU/h (2.5 kW) boost output for up to 6 hours.
• Quieter sleeping spaces: A new fan concept and brushless EC motor support whisper-quiet operation in eco mode.
• Less engine idling: Designed to heat an occupied cabin while the vehicle engine is off, with a suitable battery and fuel supply.
• Mountain-ready performance: Automatic altitude adjustment for travel to high-elevation destinations.
• Diesel fuel flexibility: Webasto also specifies paraffinic fuels such as HVO/GTL for the diesel version.
• Controller choice: Pick a simple rotary-style Rheostat or the more advanced Webasto MultiControl with display and timer.
• RVIA standards-compliant for RV and camper van applications, making it a great heating solution for diesel camper vans, Class B motorhomes, truck campers, and overland vehicles.

Who Is This Heater Best For?

This 12V diesel version is particularly well suited to vehicles where heat, battery efficiency and quiet operation matter during long stationary periods. Check the vehicle's fuel supply, 12V electrical system and installation space before ordering.

• Diesel camper vans and van conversions: A practical option for overnight camping and cold-weather road trips.
• Class B RVs and compact motorhomes: Consistent interior heating without operating the main vehicle engine.
• 12V truck sleepers: Cabin comfort for drivers during rest breaks and overnight stops.
• Overland rigs and expedition vehicles: Automatic altitude functionality is valuable on mountain routes.
• Diesel service vans and work vehicles: Heat for stationary crews, cargo-area workspaces and mobile operations where permitted.
• Suitable marine cabin applications: Webasto lists marine as an application area; confirm the exact installation approval and requirements for your vessel.

Technical Specifications

• Fuel: Diesel; manufacturer-specified paraffinic fuel (HVO/GTL).
• Rated Voltage: 12V DC.
• Continuous Heat Output: 2,400–7,000 BTU/h (0.7–2.0 kW).
• Fuel Consumption: 85–305 mL/h.
• Electrical Power Consumption: Maximum 21 W (heater specification).
• Boost Mode: 8,500 BTU/h (2.5 kW), for up to 6 hours.
• Ambient Operating Temperature: -40°F to 104°F (-40°C to 40°C).
• Altitude Capability: Automatic adjustment; operation up to approximately 18,045 ft (5,500 m), with maximum heating output available up to approximately 9,843 ft (3,000 m).
• Heater Dimensions (L × W × H): 12.6 × 5.0 × 4.9 in (321 × 127 × 124 mm).
• Heater Weight: 6.5 lb (2.95 kg); this is not the packaged kit or shipping weight.
• RV Compliance: RVIA standards compliant for RV and camper van applications.
• Mounting: Can be installed inside the vehicle or externally on the chassis, subject to Webasto installation requirements.
• Mechanical Interface: Retains the Air Top 2000 STC footplate and air inlet/outlet diameters; overall heater dimensions differ.
• Electrical Interface: Heater-side 500 mm wiring harness with an 8-pin connector and a separate 1,000 mm dosing-pump cable, or the manufacturer-specified integrated harness arrangement.
• Communications: W-Bus, LIN and CI-Bus; CAN J1939 implementation is identified by Webasto as forthcoming.
• Conformity: ECE R10, ECE R122 and CE; designed with cybersecurity requirements according to ISO/SAE 21434.

Kit Includes

• Air Top Pro 25
• Rotary Control or MultiControl
• Wire Harness ATP25 Rheostat
• Tube Flex AA 22mm x 0.5M
• Wiring Harness Extension 2M DP42 ATP25
• Standpipe 4.76 x 828mm 0.25" NPT
• Tube Flex SS 22mm x 1M with End Cap
• Tube Flex Pak 60mm x 1M
• Bag Install Hardware AT 2000 ST STC
• Bag Parts Intake Exhaust AT2000
  
• Bag Parts Fuel System Evaporative Heater
  
• Kit Mounting Plate Air Top Series
• Bag Fuel Pump DP42 ATP25

Browse Webasto Manuals & Technical Documentation

Choose Your Diesel 12V Factory Kit

Webasto Air Top Pro 25 vs. Air Top 2000 STC

Compared with the previous-generation Air Top 2000 STC, the Air Top Pro 25 expands the low-output operating range, adds a 2.5 kW boost mode and introduces automatic altitude adjustment. The specifications below compare the same fuel and voltage category, not every kit component.

Air Top 2000 STC Replacement Part Numbers

Webasto identifies 5014433A as the new-generation kit corresponding to Air Top 2000 STC diesel 12V Sleeper Kit 5012550A. The table also shows the other manufacturer-designated replacement part numbers for shoppers comparing installations.

FAQs

Will my Webasto heater still keep me warm at high altitudes?

Yes. The Air Top Pro 25 automatically adjusts for altitude and is specified to operate up to approximately 18,045 ft (5,500 m). Webasto states that maximum heating output is available up to approximately 9,843 ft (3,000 m). Above that elevation, the heater can continue operating within its stated range, but peak heat output may be reduced. Actual cabin comfort also depends on outside temperature, insulation and installation.

Can I replace my Webasto Air Top 2000 STC with the new Air Top Pro 25 without modifying my setup?

Not necessarily. Webasto retains the Air Top 2000 STC footplate and air inlet/outlet diameters, which helps with replacement installations. However, the heater body is not exactly the same size: the Air Top Pro 25 measures 321 × 127 × 124 mm, compared with 311 × 120 × 121 mm for the Air Top 2000 STC. The electrical connector, wiring harness arrangement and control interfaces also differ. Plan to check physical clearance, wiring and controller compatibility; do not assume a plug-and-play swap or reuse of every existing component. Follow Webasto installation instructions or consult a qualified installer.

What is the difference between the Rheostat and Webasto MultiControl?

The Rheostat Controller provides straightforward rotary heating control. Webasto MultiControl adds a TFT display, an instant-start button, heating and ventilation modes, and a programmable 7-day timer. Select the corresponding factory SKU rather than assuming you can interchange included components.

Can the Air Top Pro 25 heat a camper van while the engine is off?

Yes. The Air Top Pro 25 is designed for parked-vehicle cabin heating. It still needs the correct diesel fuel supply, 12V electrical power and a properly installed combustion-air and exhaust system.

Can the heater be mounted outside the vehicle?

Webasto specifies installation inside the vehicle or externally on the chassis. Mounting position, airflow, exhaust routing and water protection must follow the official installation instructions for the chosen application.

Does the kit include every installation component?

Not necessarily. Webasto offers different factory kit configurations, and the supplied launch documents do not provide a complete item-by-item list for each box. Check the confirmed contents of your selected kit before purchasing additional installation parts.

Is the Webasto Air Top Pro 25 RVIA compliant?

Yes. The Webasto Air Top Pro 25 meets RVIA standards for RV and camper van applications. It is designed for use in recreational vehicles, camper vans, and other compatible mobile heating installations. Always follow Webasto's installation instructions and applicable vehicle requirements.