Best Diesel Heaters Under $300

A bargain split heater for a van, RV or workshop on a budget. Expect closer to 5 kW than the 8 kW on the box, and no stated warranty.

A 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.

A cheap split kit with Bluetooth control and automatic altitude adjustment, for DIY installs in vans and campers that travel high. Real output is far below 8 kW.

A bargain split heater kit for a van, truck or camper install, with app control and a thermostat. Expect about 3.5 kW of heat, not 8.

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.

A small, cheap split heater with Bluetooth control and automatic altitude adjustment, sized for cars, small vans and boat cabins.

A complete split kit with a big tank and remote for trucks, trailers and boats, but it is a generic clone priced well above others like it.

A bare-bones, very cheap split heater kit for DIY installs in trucks, campers and boats at low altitude. Real output is closer to 3 kW than 8.

A very cheap complete split kit with thermostat mode and a remote, for DIY installs in RVs, garages and trucks. Specs and support are thin.

A bare-bones split heater for DIY installs in trucks, RVs and boats on a tight budget. Real output is closer to 3 kW than 8.

A quieter brushless take on the Chinese split heater for vans and RVs. Expect about 3 kW of heat, and few published specs to check it against.

An aluminum cased split kit with an honest 5 kW rating, a big tank and a remote, for truck cabs and campers. It costs more than most clones.

A small, cheap split heater for cars, truck cabs and boat cabins, with a credible 2 kW rating and a 12V or 24V supply.

A low cost 5 kW split kit for DIY truck and RV installs, sold with almost no published specs or warranty.

An aluminum cased split kit with a big tank and remote for truckers and RVers who want a sturdier clone. Its real output matches the cheaper 5 kW model.

A basic 5 kW split kit for truck, RV and boat installs, with a timer but no thermostat.

A budget 5 kW split kit with tank and remote for cars, vans and small shops, with few published specs to back it up.

A well documented budget split heater for a van, camper or truck, with a big tank and a low power draw. Treat it as about a 3 kW heater, not 8 kW.

A low cost split heater kit for a van, truck or RV that wants WiFi control and a big tank. Treat it as about a 4 kW heater, not 8 kW.

A brushless split heater with automatic altitude adjustment for vans, trucks and RVs at 12V. The listing publishes too few figures to judge its real output.

A brushless split heater with automatic altitude adjustment for vans, trucks and RVs at 12V. The listing publishes too few figures to judge its real output.

A compact 2 kW split heater for car and small truck cabs, though it costs as much as LF Bros’s 5 kW kit.

A cheap app-controlled split heater for DIY van and RV installs, though Hcalory publishes few specs for this 5 kW version.

A bare bones split heater for DIY installers in the mountains who want automatic altitude adjustment at the lowest price. The short warranty and missing specs make it a gamble.

A cheap split kit with its own tank and automatic altitude adjustment, for DIY van and truck builds at elevation. The 3 month warranty is the catch.

A cheap all-in-one heater for tents, garages and vans that adds a CO shutoff and automatic altitude adjustment, though its real output is well under the 8 kW rating.

A very cheap heater with thermostat, app control and a two year warranty, for tents, garages and occasional van use. Expect closer to 4.2 kW than the 8 kW on the box.

A cheap upright all-in-one heater with an app, timer and automatic altitude adjustment, for tents, garages and high-country camping. Expect well under its 8 kW rating.

A cheap all-in-one heater with app control and a two year warranty, for tents and small vans, with real output closer to 3.6 kW.

A budget toolbox heater for tents, garages and vans with a CO shutoff and a thermostat. Treat it as about a 4 kW heater, not 8 kW.

A cheap carry-handle heater for garages, campers and vans that still holds a set temperature. Expect about 3.6 kW of heat, not 8.

A budget toolbox heater for vans, garages and camps with the smart controls of pricier models. Expect about 3 kW of heat, not 8.

A budget all-in-one heater with a big tank and automatic altitude adjustment, for garages, tents and campers that need long runtimes.

A basic all-in-one heater with a big tank and a wall adapter, for garages and tents where an app and altitude mode are not needed.

A mid-priced toolbox heater for vans, cabins and camps that holds a room temperature well and handles high altitude. Expect about 3 kW of heat, not 8.

A rolling toolbox heater with app control and a CO alarm, for garages and job sites, though its 8 kW rating has no fuel figure behind it.

A low-cost all-in-one heater with a large tank and a wall adapter, for garages and tents at low altitude.

A plain all-in-one heater with a big tank and a wall adapter, for garages and workshops that want long runtimes without extras.

A budget portable heater for garages, tents and vans with a thermostat, timer and wall power. Treat it as about a 3 kW heater, not 8 kW.

A portable all-in-one heater with a CO shutoff and Bluetooth control, for garages, workshops and camping. Expect well under half its 8 kW rating.

A portable all-in-one heater with a CO shutoff and Bluetooth control in a camouflage case, for camping, garages and workshops. Real output is well under 8 kW.

A portable heater for tents, garages and vans with WiFi control, a thermostat and a CO shutoff at a mid price. Treat it as about a 4 kW heater, not 8 kW.

A well-equipped toolbox heater for campers and garages that want long runtimes, altitude adjustment and quiet nights. Expect about 3 kW of heat, not 8.

A portable toolbox heater for tents, garages and vans that wants WiFi control and a CO shutoff. Treat it as about a 4 kW heater, not 8 kW.

A small portable heater for a car, truck cab or tent where 8 kW clones are far too much. Its fuel figures back up its 2 kW rating.

A basic all-in-one heater with a remote and wall power, but its listing leaves out too many details to recommend over better documented rivals.

A compact portable heater for small garages, tents and vans that need mains or battery power and a timer.

A portable heater with app control and tidy storage for garages, trucks and camps. Expect about 3 kW of heat, not 8.

A portable heater for tents, ice fishing and car camping from a brand that publishes honest output and power figures. Good for running off a power station.

A portable heater for tents, garages and vans for buyers who want brushless motors, WiFi control and a CO shutoff. Treat it as about a 4 kW heater, not 8 kW.

A pricier all-in-one heater with Bluetooth control and an insulated case, for tents and boats, but with no fuel figures to check its 5 kW rating.

A small, cheap portable heater for a car, tent or small camper, with a CO shutoff that most budget heaters lack.

A portable toolbox heater for a garage, shop, tent or camper that has a wall outlet or a battery. Treat it as about a 3 kW heater, not 9 kW.

A plug-and-play portable heater for garages, workshops and tents, with mains power included but few controls.

One of the cheapest all-in-one heaters with Bluetooth control, for tents and small spaces, though its 8 kW rating has no fuel figure behind it.

A quiet, low-draw portable heater for tents and vans that runs off a battery, with honest output figures but no app.