GEARLASSO 8KW Portable Diesel Air Heater 12V/24V All-in-One Parking Heater

How big a space can this heater warm?

The listing says it heats areas up to 25m². Output runs from 4,700 to 17,000 BTU. The heater has two speeds and a temperature range of 8°C to 40°C.

What does that look like in real use? One buyer runs it in a 6.5 x 3.5m summerhouse. That is about 23m². They say it heats the space well on half power. Others use it in garages and workshops. A campervan or boat cabin is much smaller than 25m² and should warm faster.

How long does it take to warm up?

The listing gives a heat-up time of 5 to 10 minutes. A workshop owner says it heats the space "in no time at all". Another buyer says it heated their cabin well.

Starting can take a moment. One buyer needed two attempts to fire up after filling the tank with fuel. The fuel line has to be fully primed first. Once running it held steady for a long time.

Does it really produce 8KW of heat?

It is rated as an 8KW unit. The listed output is 4,700 to 17,000 BTU. Not everyone is convinced. One reviewer says it does not put 8KW of heat into a room.

Most buyers are happy with the warmth. Around 87% of the 112 ratings are 4 or 5 stars. Heat output was praised by 7 of the 8 customers who mentioned it. Treat the 8KW figure as a maximum and size it to your space.

How much diesel does it use and how long does one tank last?

Fuel use is 0.15 to 0.45 litres per hour. The tank holds 5 litres. At full power that gives roughly 11 hours. At the lowest setting it could run for around 33 hours.

The listing says combustion is nearly 100%. This comes from a precision oil pump and a ceramic glow plug. One buyer ran it for 6 hours and then nearly 12 hours on full power the next day. They described fuel use as minimal.

Is it safe to leave on overnight?

The listing says yes. It has smart thermostat control and automatic shutdown protection against overheating. The exhaust is external so fumes stay outside the living space.

Fit it correctly though. The exhaust pipe must vent outdoors and have clearance from anything that can burn. The unit has an exhaust heat shield made with glass wool. A German buyer says it itched their hands for about three days. Wear gloves when you handle it.

What power supply does it need and how do I control it?

It runs on 12V or 24V. It does not plug into a household socket. A buyer who runs it away from a vehicle bought a small battery for it. The unit is rated to work from -40°C to +50°C.

You get an LCD panel on the unit and a wireless remote. Both adjust temperature, heating mode and fuel pump frequency. The colour listed is "No App" so there is no phone control. The remote means you do not need to leave your bed.

How noisy is the Diesel Air Heater 8KW?

The listing mentions low-noise technology and a muffler silencer. Buyers still report some noise. The main source is the fuel pump. One calls it a bit noisy. A German buyer says the pump clicks loudly.

That buyer would mind it in a camper but not in a garage or garden room. Another reviewer says some noise is normal for this type of heater. Mount the pump away from your sleeping area if you can.

What problems should I watch for when setting it up?

Reviewers raise three points. The first is the instruction booklet. Three say it is hard to follow. One learned more from YouTube videos than from the booklet. The second is the exhaust pipe. Two buyers found it too short. One ordered a 3m replacement with heat protection tubing. The third is the fuel line. One buyer found pressure popped the line off because the ends were not tight. Check both ends before you fill the tank.

Other points came up too. One buyer added wooden blocks under the feet to lift the exhaust pipe. Another found the air outlet pipe short. A buyer who wanted two outlets bought a double vent. The box contains the heater only. The listing has a 2 year warranty and a 30-day right of return.