Succinct and pertinent information regarding the install of a cheap, Chinese diesel heater in your van, trailer, or motorhome.
Chinese diesel heaters have become all the rage with the explosion of “Van Life” and DIY Aisrtream and RV restorations. For around $200 for a 5KW unit, there is NO cheaper way to get a LOT of heat into your rig’s living space. There isn’t a lot of quality control, and there is certainly NO chance of holding one of these manufacturers responsible for anything that goes wrong, so using one of these heaters is solely the risk and responsibility of the person purchasing and installing them. As such, one should take every measure to mitigate any possible dangers or faults that might result from the install. There’s nothing you can do about defective equipment or something that wasn’t put together correctly at the factory (except not buy one of these in the first place), so it’s even more important to make sure the install is as perfect as possible.
If the above information worries you and you have a little more cash to spend (well… quite a bit more, actually), you are in luck. Eberspacher and Webasto are two companies that have been making these heaters for decades (and even ones that run on regular fuel instead of diesel), so you have the option of spending around $2-4k for a really fantastic version of these Chinese risks. :-D Buying from Eberspacher or Webasto also means you will get great customer service to help with the purchase and install, as well as a warranty. These companies really are excellent, so if you have the money, I highly recommend going the much safer route.
Before I get to the installation information (that’s fun to say!), I want to point out that there is a lovely Australian gentleman who goes by John McK 47 on YouTube who has put together a series of around 20 videos that present the most useful and pertinent information on this subject anywhere. Seriously. I can’t believe how thorough and informative these videos are (and I don’t think he’s even monetized his videos –he’s just created and presented all this stuff for the good of humankind!). You would be doing yourself a huge favor to watch every single one of his videos on the Chinese diesel heater topic.
Finally, this is far from the most comprehensive post on the topic of Chinese diesel heaters. Think of it more like the information you need for your install once you’re sick of reading the hundreds and hundreds of posts on this topic and you just want to get to putting the heater in your vehicle. So let’s go…
Mounting the Heater Body
On my first install it took me a while to decide how to mount the unit, and what kind of a hole was necessary for the intake/exhaust ports on the bottom of the unit. Now that I’ve installed a couple of these, I feel like I’ve got it down. Here are some tips regarding mounting the heater to the floor…
The metal plate should be mounted to a flat and stable surface. The plate doesn’t seem to get that hot, but on my first install I thought I would go the extra mile and place ceramic fiber blanket between the mounting plate and the deck (the subfloor of the trailer). After a bit of use, I think the ceramic blanket is overkill, but I do think a sheet of high temp silicone (the material used for modern oven mitts) can be a good idea. Not only does it offer peace of mind regarding high temps against wood decking, but it also offers a little vibration absorption to help mitigate the noise caused by the heater being fastened to a huge flat surface which inevitably acts as a drum/amplifier.
Pro tip: you should put almost everything together before you fasten the heater to the floor; this way, you don’t have to make all the connections on your back while crawling under the vehicle. Thread the fuel pump electrical wire and coupler through the deck plate keyhole (that little extra hole connected to the intake hose hole), then fasten the deck plate to the heater. Fasten both the exhaust hose and intake hose, and then attach a small piece of rubber fuel hose to the fuel port to be used for attaching the nylon fuel feed tube once it’s time to hook up the fuel pump. When you’ve got all this put together, you can see what kind of hole you should create in your mounting surface. It can be rectangular or round. Just make sure of two things: the hole should be smaller than the mounting plate, but it should be big enough to give as much clearance as possible for any heat coming off the exhaust outlet.
The end of the exhaust hose should not be anywhere near the opening of the air intake hose. If you are installing the heater on a moving vehicle, make sure the exhaust is behind the intake. Also make sure your exhaust hose does not have any low points between the heater and it’s termination point. Moisture is one of the things being “exhausted,” so if there is a low point in the exhaust hose, then water will pool in that area.
Along the same lines, make sure you position the exhaust muffler on it’s side. It might seem like it’s meant to be mounted flat against the deck/floor, but it actually has a top and bottom edge, and should be mounted against a side support, so moisture can drain out of tiny holes in the bottom edge of the muffler.
The fewer bends in your intake/exhaust, the more efficiently your heater will run. There are specific guidelines on maximum lengths and number of bends, but I’m trying to keep this post tight! Just remember, the fewer restrictions on your lines, the happier your heater will be.
On the *feed* side of the pump (between the pump and the heater), you want hard nylon tubing, not soft rubber. These pumps are made to feed intermittent fuel to the heater separated by tiny bubbles. If you use rubber tubing, the vibration will be absorbed and the bubbles won’t properly form. Typical rubber fuel lines can be used on the intake side of the pump (from the tank to the fuel pump), but anything after the pump should be the hard nylon line. Your heater most likely came with some rubber fuel line (hopefully in addition to the hard nylon line), and that rubber hose should be used as the unions where the nylon tube attaches to things like the pump, filter, and heater. Make sure that the nylon tubing presses directly against anything with which it is being coupled. If there is a gap inside the rubber fuel line being used as a union, air gaps can form inside the rubber hose and will disrupt the flow of fuel to the heater. From what I have read, it’s not a good idea to make the nylon supply line any longer than around 3 meters (15 feet) and the supply side rubber hose shouldn’t be any longer than 3 feet. In any case, the shorter the fuel lines the better.
The Fuel Pump
The fuel pump should be placed as close to the fuel source (the tank) as possible. It is easier for the small pump to push fuel than to pull it. The fuel pump should also be placed on a slight incline. By design, these pumps make tiny little bubbles that you want *floating up.* You can get away with placing the pump completely horizontal, but if the flow is positioned at all down, the pump will not function properly, so it’s best to position it with the “out” port above the “in” port. You also want your fuel
The Plastic Fuel Tank
I’m not sure how great these tanks are for this purpose. The tanks that are included with these heaters are translucent plastic. If you mount them exposed to sunlight (whether it’s inside or outside the vehicle), your fuel will be compromised by UV rays. Not only that, but the plastic tank itself will also break down over time. I think it would be better to utilize an aluminum or stainless tank.
The included plastic tank does not come with the “bung” (the fuel port) installed. You need to drill a hole and install the port. If you haven’t done it before, it seems impossible. How in the world do you hold the port from the back side… inside the tank?! The answer is either a wire or string. Drill the hole for the port, then feed a wire, coat hanger, or string through the hole from outside of the tank, through the tank, and out through the fill port (where you pour the fuel in). Next place the bung over the wire or string and let it slide down to the hole. If you used a string, tie a nut to the far end so you can pull the string tight to pull the bung through the hole. If you used a wire or coat hanger, bend the far end into an L shape, so you can pull the bung through the hole. You can make the hole a bit smaller than the bung threads so that the bung actually threads into the plastic, or you can just rely solely on the rubber washers pressed on the inside and outside of the tank.
Some people say putting a bung in the bottom of the tank isn’t a good idea because you’ll get sediment in your fuel line. The preferred method is using an “uptake” line positioned 2cm from the bottom of the tank (like in a car’s fuel tank). With these little pumps, I don’t think it’s a good idea to make them work harder in order to *suck* fuel up a fuel uptake. Since you want the pump as close to the fuel source as possible, if you’re adding a fuel uptake, you’re basically moving the pump farther away from the source and making it work harder. Not only that, but if your heater is mounted on the floor, it’s usually going to be difficult to place the tank much lower than the heater (to keep the fuel feed moving up as it should). Therefore, it’s best to let gravity do it’s work with getting fuel to the pump, and the bung needs to go in the bottom of the tank. Just make sure you check your fuel filter regularly so the flow of fuel isn’t being blocked by sediment that may collect in the bottom of the tank. The bung is also made with extra material on the inside of the tank, so that the port is actually around 1cm above the very bottom of the tank. Thus, even a bottom mounted bung is pulling fuel from a similar gap to what an uptake would utilize.
Additional (important) information…
Make sure you prime the fuel pump before starting the heater. Simply put, this means getting fuel going through the fuel lines without actually running the heater. This clears the air from the fuel lines and allows the fuel to lubricate the interior heater parts, so the heater is not “running dry” when it begins the start cycle. For units with a digital panel, priming is activated by pressing the down arrow and OK button at the same time until the read out shows H-OF. The pump will activate when you let go of those buttons and press the up arrow so the read out reads H-ON. Press the down arrow again to halt the pump. If you have a manual knob controller, turn the knob so that the low/high indicator lights up, then press the “off” button for more than three seconds to activate the pump. Once you have let the pump run for a while to prime the pump and lines, press “off” again to halt the flow of fuel.
The flexible tubes (exhaust, intake, heat routing) that come with these units aren’t of the greatest quality. You may want to update your tubes, dude.
Though it may seem like a good idea to put the heater on a switch, DON’T DO IT. These heaters have various cycles that keep them functioning efficiently and safely. If the power is cut before the heater can finish one or more of these cycles, it can damage the heater and/or lead to dangerous operating conditions.
Finally, make sure you install a carbon monoxide detector! It could be the difference between life or death. If that sounds dire… it is!
For more complete information, I think this guy put together a pretty good (and more comprehensive) post on the subject of Chinese diesel heaters (probably the “easiest” single-source on the topic, if that’s more what you’re after): https://www.vanlifeuksurvivorsguide.co.uk/post/fitting-your-own-chinese-diesel-heater-everything-you-need-to-know