Espar Airtronic S3 D2L
#2 in SplitFull review
For van, truck and boat owners who want a quiet, type-approved 2 kW heater that works at high altitude. It costs much more than clones but is built to run for thousands of hours.
Amazon $1,250$1,250
The Espar Airtronic S3 D2L and the Autoterm Air 2D are evenly matched, rated 3.5 and 3.5. The Espar Airtronic S3 D2L leads on controls and safety. The Autoterm Air 2D costs $300.01 less ($949.99 vs $1,250).
Autoterm Air 2D
#3 in SplitFull review
For van and boat owners who want a type-approved 2 kW heater for less than Webasto or Espar. Add a timer panel if you want it warm before you wake.
Amazon $949.99$949.99
Prices were last checked October 30, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Espar Airtronic S3 D2L for controls and safety (holds a set temperature, automatic altitude; no CO sensor vs holds a set temperature, automatic altitude; no CO sensor).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every split diesel heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Espar Airtronic S3 D2L | Autoterm Air 2D |
|---|---|---|
| Overall rating | 3.5/5 | 3.5/5 |
| Value 25% | 2 $568 per kW ($1,250, 2.2 kW) | 7 $475 per kW ($949.99, 2 kW) |
| Type approval 20% | 100 type approved (ECE R122) | 100 type approved (ECE R122) |
| Controls and safety 15% | 65 holds a set temperature, automatic altitude; no CO sensor | 50 holds a set temperature, automatic altitude; no CO sensor |
| Power draw 15% | 73 up to 27 W running | 69 up to 29 W running |
| Warranty 15% | 50 2-year warranty | 50 2-year warranty |
| Low setting 10% | 96 down to 0.8 kW | 100 down to 0.8 kW |
Specifications
| Espar Airtronic S3 D2L | Autoterm Air 2D | |
|---|---|---|
| Heating | ||
| Heat output (maker) | 2.2 kW | 2 kW |
| Lowest output | 0.8 kW | 0.8 kW |
| Fuel burn | 0.1 to 0.27 L/h | 0.1 to 0.24 L/h |
| Build | Split (installed) | Split (installed) |
| Power | ||
| Supply | 12V | 12V |
| Running draw | 6 to 27 W | 10 to 29 W |
| Starting draw | 90 W | - |
| Controls and safety | ||
| Thermostat | Yes | Yes |
| Automatic altitude | Yes, to 13,120 ft | Yes, to 13,780 ft |
| App | - | No |
| Timer | - | No |
| Remote | - | No |
| CO shutoff | No | No |
| Type approval | ECE R122 | ECE R122 |
| Build | ||
| Dimensions | 12.2 x 4.5 x 4.8 in | 12.2 x 4.7 x 5.7 in |
| Weight | 5.5 lb | 6.4 lb |
| Warranty | 2 years | 2 years |
| Released | 2021 | - |