For van and truck owners who want a new type-approved 2 kW heater with altitude adjustment and a very low idle setting, or a drop-in replacement for an Air Top 2000 STC. It costs far more than clone heaters of the same size.
Price checked October 30, 2026. As an Amazon Associate we earn from qualifying purchases.
The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its type. How we rank explains each one.
| Model number | Air Top Pro 25 diesel 12V high altitude rheostat kit (5014433A) |
|---|---|
| Heating | |
| Heat output (maker) | 2.5 kW |
| Lowest output | 0.7 kW |
| Build | Split (installed) |
| Power | |
| Supply | 12V |
| Controls and safety | |
| Thermostat | Yes |
| Automatic altitude | Yes, to 18,045 ft |
| App | No |
| Timer | No |
| Remote | No |
| CO shutoff | No |
| Type approval | ECE R122 |
| Build | |
| Dimensions | 12.6 x 5 x 4.9 in |
| Weight | 6.5 lb |
| Released | 2026-07 |
For larger vans, trucks and boats that need a type-approved 4 kW heater that works anywhere, including high mountain passes. It costs far more than clones but is built for years of daily use.
Amazon $1,675For larger vans, sleeper cabs and boats that need a type-approved 4 kW heater with a wide turndown. The M3 D4L that replaces it costs the same and draws less power.
Amazon $1,675A cheap small split heater for a van, truck cab or small boat cabin. Its fuel burn backs up the 2 kW rating, but the maker gives no warranty length or power figures.
Amazon $99.99Compare the Webasto Air Top Pro 25 with any other diesel heater →
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