12V 5KW Diesel Air Heater

How much heat does this heater produce and is 5KW enough for a van or motorhome?

The Diesel air heater 12V 5KW gives a heat output of 4700-17000BTU. That is roughly 1.4kW at its lowest setting and 5kW at its highest. The range matters because the unit raises and lowers its output to hold the temperature you set.

Is that enough for a large vehicle? One reviewer got a large van up to 25°C in no time. They tested it with an outside temperature of -15°C. Another owner used it in a Sprinter and called it more than adequate. A French owner with a six-berth motorhome said it heated very well and even too much. Their old 4kW heater could be limited in power. They said this one pushed the cabin to almost 25°C even on the lowest setting unless they switched it off.

So 5KW suits vans and motorhomes well. For a small car or a compact camper it may be more than you need.

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

Fuel consumption is 0.18-0.53L per hour. The low figure applies at minimum output and the high figure at maximum. Real use depends on the temperature you set and how cold it is outside.

The tank size is listed differently across the page. The title says 9L and the bullet points say 10L. One buyer measured the tank supplied at 7.33 litres. Here is what each size gives you:

9L tank: about 17 hours at maximum output and about 50 hours at minimum.

7.33L tank: about 14 hours at maximum and about 41 hours at minimum.

One buyer upgraded to a bigger tank because they found the supplied one small. They still rated the heater itself highly.

Does it need drilling or cutting into the vehicle?

The title says no-punching. The heater comes as a split unit with its own separate fuel tank. That means you do not need to cut into your main fuel tank to run it. One reviewer fitted it to a Talbot motorhome and said the tank was a perfect size for the seat base.

The pack contains the heater and an instruction manual. The listing says nothing else is included. Reviewers mention a tank and a clear fuel pipe arriving with theirs. Check what you receive before you start.

Some people still run their own wiring. One buyer used 4.5mm flat automotive cable for the run to the battery. They also added an inline fuse holder as close to the battery as possible.

Is it difficult to install?

Reviewers say no. One buyer swapped it like for like in a campervan. They described themselves as not a mechanic in any sense and followed YouTube videos. Another fitted it in a car and had the temperature rising within three minutes.

There is one gap in the paperwork. A Spanish reviewer said the manual should tell you to purge the fuel circuit before the first start. Without this the pump has no fuel in the line. Prime the fuel line first and the heater should fire up as expected.

One more point from a reviewer with an older Talbot motorhome. The tank did not come with the pickup piece that goes into a vehicle fuel tank. It did not matter for them because an older vehicle tank has no place for it. Check this if you plan to draw from your main tank.

How loud is it and does the muffler help?

The listing says a muffler is included and describes low-noise running. One reviewer said it made the heater quiet and unobtrusive. No decibel figure is given so I cannot give you an exact number.

One thing to know about diesel heaters in general. The fuel pump makes a ticking sound as it pulses. A reviewer said they may swap to a silent diesel pump later. They called it a luxury rather than a need. Where you mount the pump and tank makes a difference to how much of that you hear.

How does the remote control work and how far does it reach?

You get an LCD display on the unit and a remote. Both let you adjust the temperature. The timer and thermostat can be set automatically or by hand through the display. The remote lets you preheat the vehicle before you get in.

What about range? A Spanish reviewer measured about 20m without obstacles. A UK buyer said you need to be pretty close and so rarely bothers with it. Walls and bodywork cut the signal. One owner also said they had not needed to buy a replacement remote after months of use.

What safety features does it have and how much power does it draw from the battery?

The heater has protection against overheating and short circuits. It also covers overcurrent and overvoltage. Reverse connection is protected too. If it overheats it powers off automatically. The case is made of heat-resistant aluminium alloy.

Battery drain is low. The same Spanish reviewer measured 0.2 milliamps on standby and 0.3 milliamps when awake but not running. That is barely noticeable even if the vehicle sits for weeks. Running draw is higher while it ignites and burns. A ceramic glow plug lights the fuel. The combustion chamber casing is steel precision casting. The makers say the fuel burns fully so carbon deposits do not build up.

How reliable is it and what do owners complain about?

The heater scores 4.1 out of 5 from 140 ratings. 67% of ratings are five stars and 9% are four stars. 13% are one star. That split tells you most owners are happy but some had real problems.

The main complaint came from a buyer whose unit failed after three months. They said the main board kept blowing the glow plug and pump. Another owner reported it still working perfectly many months on. Most buyers who praised it had used it for days or a few months. Long-term data is limited. The listing first appeared on 16 December 2023.

Amazon allows returns within 30 days on many products. The Diesel air heater 12V 5KW weighs 6.11kg and measures 36 x 26 x 20cm. Test it soon after delivery so you can return it if it has a fault. Delivery outside mainland UK is not available for some products.