By Joe Gresh
Towards the end of last year’s heating season the Vevor 12-volt, 5kw diesel heater started shutting down and giving an error code. The big blue, start/stop button on the front of the machine blinks the code number between pauses. I counted an error No. 8, which the owner’s manual said was a problem with the temperature sensor. This was a little disappointing because I had only run 10 gallons of diesel through the heater. (It runs a long time on a gallon, like 8 hours) I didn’t mess with it at the time as it was warming up and I was busy doing other vital, yet unimportant tasks.
Fast-forward to winter, 2024 and it’s cold again so I figured I’d better fix the heater. I looked up a new temperature sensor for $4 on Amazon and after waiting a few weeks the thing came all the way from China. Installing the new temperature sensor changed nothing. The heater kept shutting down with an error code No. 8.
Utube Academy provided some more ideas, one of which was the fuel pump was not functioning good enough to keep the fire going. I bought a new fuel pump on Amazon for $18 and installed it. After bleeding the air out of the pump the heater turned on for a few minutes and then shut down showing error code No. 8 again.
Another Utube suggestion was that the glow plug was bad, failing to ignite the diesel fuel. While looking up the glow plug @ $19 I found a complete new heater for $90 with free delivery. I stuck the new heater in the shopping cart and it showed up a few days later.
The new heater was almost an exact duplicate of the Vevor unit and in fact it had a more advanced keypad display instead of a blue button. The replacement unit swapped out easily and in no time I had heat in the shed.
A few more weeks passed and the new glow plug showed up. Taking the unit apart to gain access to the plug was easy and I pulled the wires off of the glow plug so I could put a socket on the thing. That wasn’t a good idea. Turns out the wires are non-removable and you need a special 12mm slotted deep socket to unscrew the plug. When I pulled the wires off I actually broke the glow plug ceramic. The special socket for the plug was helpfully included in the box with the new glow plug. Unfortunately, I didn’t realize this before destroying the old glow plug. That’s just how I roll.
None of this mattered because once I started taking the heater apart I noticed the exhaust port was almost plugged with diesel soot.
It was so clogged I had to take the fuel feed pipe and the combustion chamber apart to clean out all the soot.
The gaskets tore when I dismantled the fuel feed and the combustion chamber so I had to order new gaskets from Amazon @$16. If you’re keeping count I now had almost as much in parts as a heater costs.
These Chinese diesel heaters are pretty simple to work on and after cleaning the combustion chamber and exhaust pipe it was only a few minutes to put the whole thing back together. I rigged it up for a test run and the heater put out plenty of hot air and ran for as long as I wanted to hear it run. It seems to be fixed but I don’t understand why it sooted up so soon. Maybe there was another issue that I have inadvertently fixed while swapping out parts? Maybe not. Keep clicking on ExhaustNotes and I’ll report on this situation as it develops.
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How long will these heaters run on a full tank of D?
How many BTU?
And how are you venting these?
Interesting thread .
I’m not sure the BTU, the heater is rated in KW. You control the heat by changing the frequency on the fuel pump pulses.
Venting is done by running the exhaust and intake outside the building. The inside heat exchanger is just hot air.
You could put the entire unit outside and run vent/return ducting into the building. That would be quieter.
Thanks for talking me out of one of these things for my shed. I lived in NM for a few months during the early spring. It gets cold at night, but it’s a dry cold. I think you should go with a small wood stove and start collecting wood pallets. The good oak ones.
Pallets are a PIA. Especially breaking them down to wood stove size.
I think the best deal is running some type of solar powered electrical heat.
I believe so too but nighttime would be a problem. I’ve seen people make solar heaters out of aluminum beer cans enclosed in a wood frame and glass case with a small solar cell to operate a fan.
Interesting Project… I too had looked at those for a small building, after seeing the clogged exhaust I am glad I choose to re-purpose an RV furnace for my small machine shop.
Burns Clean LP, no odor, automatic with a thermostat, but even used not nearly as cheap to buy and fix.
Thanks for the Nice Article,
Lance
It’s hard to know, sometimes, when you’ve reached the repair cost tipping point. But the psychological exercise and the happiness at finding and fixing the problems are positive and significant. We need to remember to factor those in too, if you’re not doing it for a living.
Those of us of a certain age would almost always attempt to repair something rather than toss/repurchase regardless of cost. I think it is the triumph of user over suspect manufacturer that keeps us going.
Used Triumphs certainly fit this category!
Its cheap. Its Chinese. Its going to have problems.
Maybe you’d received a used unit?
Sometimes we get into parts replacing since we can’t anticipate the outcome. You looked at symptoms like anyone would. I like the perseverance and honesty in sharing the process. Like you, wondering what caused the initial sooting. It’ll either manifest again or it is fixed for good. The Chinese diesel heaters are a big subject on the camper conversion sites I look at. Nomads use them in a variety of ways. Incredibly efficient and supposedly simple to install and operate. Thanks for sharing
There is no sooting with LP. And in some cases no venting required.
From what I’ve read the heaters don’t clog up all that often. They will need to be cleaned eventually. There is an altitude function on the remote that I may look into. Possibly it is burning too rich? The new heater has no altitude function.
It’s not hard to take apart and I’ve learned to check for clogging before buying parts.
Save the slotted socket as it may come in handy for use on O2 sensors in the exhaust system of four-wheeled vehicles. 12mm is probably too small for most of them, but you never know.
Thanks for the article. I never knew these existed. I have owned a forced air propane heater for several years, and it has worked flawlessly, however, it runs on 120v, and I imagine the fan would drain a 12v battery with an inverter rather quickly. Also it doesn’t appear to run as efficiently as your diesel heater. I may look into one of these in the future.