Hcalory UNIT 2 8kW Diesel Heater
#12 in SplitFull review
A well-featured split heater for van and RV builds that want automatic altitude handling and a big tank; expect about 3 kW of real heat, not 8.
Amazon $169.99$169.99
The Hcalory UNIT 2 8kW Diesel Heater rates 3.2 among split diesel heaters; the Hcalory Toolbox Compact 2S rates 3.1 among all in one ones. The Hcalory Toolbox Compact 2S costs $40 less ($129.99 vs $169.99).
Hcalory Toolbox Compact 2S
#8 in All in oneFull review
A budget toolbox heater for vans, garages and camps with the smart controls of pricier models. Expect about 3 kW of heat, not 8.
Amazon $129.99$129.99
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.
Scores side by side
These two sit in different type classes (split and all in one), and each is scored against the reference points for its own class, so a rating says how well each does among its own type peers. How we rank explains each factor.
| Factor weight | Hcalory UNIT 2 8kW Diesel Heater | Hcalory Toolbox Compact 2S |
|---|---|---|
| Overall rating | 3.2/5 | 3.1/5 |
| Value 25% | 72 $61 per kW ($169.99, 2.8 kW); 8 kW claimed, more than its fuel burn can supply | 70 $45 per kW ($129.99, 2.9 kW); 8 kW claimed, more than its fuel burn can supply |
| Type approval 20% | 0 no type approval published | 0 no type approval published |
| Controls and safety 15% | 90 holds a set temperature, automatic altitude, app, timer | 90 holds a set temperature, automatic altitude, app, timer |
| Power draw 15% | 50 power draw not published (neutral score used) | 50 power draw not published (neutral score used) |
| Warranty 15% | 0 1-year warranty | 0 1-year warranty |
| Low setting 10% | 83 down to 1 kW (from its lowest fuel burn) | 83 down to 1 kW (from its lowest fuel burn) |
Specifications
| Hcalory UNIT 2 8kW Diesel Heater | Hcalory Toolbox Compact 2S | |
|---|---|---|
| Heating | ||
| Heat output (maker) | 8 kW claimed (about 2.8 kW from its fuel burn) | 8 kW claimed (about 2.9 kW from its fuel burn) |
| Fuel burn | 0.12 to 0.35 L/h | 0.12 to 0.36 L/h |
| Fuel tank | 15 L | 5 L |
| Build | Split (installed) | All in one |
| Power | ||
| Supply | 12V/24V | 12V/24V/110V |
| Controls and safety | ||
| Thermostat | Yes | Yes |
| Automatic altitude | Yes, to 16,400 ft | Yes, to 18,000 ft |
| App | Bluetooth | Bluetooth |
| Timer | Yes | Yes |
| Remote | Yes | Yes |
| Type approval | None published | None published |
| Build | ||
| Dimensions | 15.71 x 5.59 x 6.97 in | 16.5 x 10.6 x 11.8 in |
| Weight | 16.8 lb | 24.7 lb |
| Warranty | 1 year | 1 year |
| Released | 2026-07 | 2025-09 |