Espar Airtronic M2 D4L
#6 in SplitFull review
For 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 $1,675$1,675
The Espar Airtronic M2 D4L is the better diesel heater overall, rated 3.4 to 2.9. The Espar Airtronic M2 D4L leads on type approval. The TJHSM 5kW Diesel Heater costs $1,591.72 less ($83.28 vs $1,675).
TJHSM 5kW Diesel Heater
#23 in SplitFull review
A low cost 5 kW split kit for DIY truck and RV installs, sold with almost no published specs or warranty.
Amazon $83.28$83.28
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 M2 D4L for type approval (type approved (ECE R122) vs no type approval published).
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 M2 D4L | TJHSM 5kW Diesel Heater |
|---|---|---|
| Overall rating | 3.4/5 | 2.9/5 |
| Value 25% | 11 $419 per kW ($1,675, 4 kW) | 50 no credible heat rating (neutral score used) |
| Type approval 20% | 100 type approved (ECE R122) | 0 no type approval published |
| Controls and safety 15% | 65 holds a set temperature, automatic altitude, timer; no CO sensor | 57 timer |
| Power draw 15% | 40 up to 42 W running | 50 power draw not published (neutral score used) |
| Warranty 15% | 50 warranty not published (neutral score used) | 50 warranty not published (neutral score used) |
| Low setting 10% | 92 down to 0.9 kW | 50 lowest setting not published (neutral score used) |
Specifications
| Espar Airtronic M2 D4L | TJHSM 5kW Diesel Heater | |
|---|---|---|
| Heating | ||
| Heat output (maker) | 4 kW | 5 kW |
| Lowest output | 0.9 kW | - |
| Fuel burn | 0.11 to 0.51 L/h | - |
| Build | Split (installed) | Split (installed) |
| Power | ||
| Supply | 12V | 12V |
| Running draw | 6 to 42 W | - |
| Starting draw | 100 W | - |
| Controls and safety | ||
| Thermostat | Yes | - |
| Automatic altitude | Yes, to 9,840 ft | - |
| App | No | - |
| Timer | Yes | Yes |
| Remote | No | Yes |
| CO shutoff | No | - |
| Type approval | ECE R122 | None published |
| Build | ||
| Dimensions | 14.8 x 5.5 x 5.9 in | - |
| Weight | 9.9 lb | - |
| Released | 2018-07 | - |