If you’ve got a Chinese diesel heater in your van, chances are it’s been a game-changer for keeping warm during those chilly nights on the road. But like all budget-friendly kit, they can throw a wobbly from time to time. When they do, you’re usually met with an ominous E-code flashing on your controller and a heater that stubbornly refuses to fire up.
Instead of panicking (or cursing while shivering in your sleeping bag), let’s break down the most common errors and how to actually fix them. I’ve been through most of these myself over the past few winters, so this comes from real-world van life experience.
The Root Cause Reality Check
Before we dive into specific codes, here’s the truth about Chinese diesel heaters: 90% of faults come down to four things – dodgy battery voltage, poor wiring connections, blocked airflow, or fuel system issues. Keep that in mind as we go through each error.
E01 – Under Voltage
What it means: Your battery isn’t supplying enough juice. These heaters are power-hungry beasts that need a solid 12V to run properly, and anything below that sends them into shutdown mode. I had a similar issue with my Halford compressor fridge showing E01
How to fix it:
- Check your battery voltage with a multimeter. If it’s below 12V, charge it up properly
- Inspect all your wiring connections – corrosion and loose terminals are voltage killers
- Consider if your battery is getting old and tired. Van life is hard on batteries, and they don’t last forever
- Pro tip: If you’re getting E01 errors mostly at startup, your battery might be fine for lights but struggling with the heater’s initial power draw.
Power Draw Reality Check: Chinese diesel heaters typically draw 6-10 amps during startup for about 2-3 minutes Dieselheat – How much power does a diesel air heater use?, though some users report seeing up to 17-18 amps on startup from the glow plug for a few minutes YBW ForumMotorhomecraic. After the initial startup phase, ongoing power consumption drops to just 1-2 amps depending on the heater’s power output and fan speed Dieselheat – How much power does a diesel air heater use?.
The same high power draw happens during shutdown – most heaters activate the glow plug again during shutdown to help clean it, which results in another short burst of higher power usage Dieselheat – How much power does a diesel air heater use?. This purge cycle burns off excess fuel and prevents carbon buildup.
The Battery Cusp Problem: You might have a battery that’s just on the edge – enough capacity to keep the heater running at 1-2 amps, but not enough to handle the 10+ amp startup or shutdown demands. This is especially common with smaller leisure batteries or older batteries that can’t deliver high current bursts.
Split Charge Relay Tip: If you’re running a split charge relay system, fire up the heater the moment you’ve parked up with the engine still running. This way the startup draw comes from your alternator rather than your leisure battery, giving you maximum battery capacity for the night ahead.
Wire Size Matters: Poor wiring can cause voltage drops that make the heater compensate by drawing even more amps Chinese Diesel Heater, powering the thing. | DIY Solar Power Forum – some users report seeing over 20 amps on undersized wire Chinese Diesel Heater, powering the thing. | DIY Solar Power Forum. Use proper 10-12 AWG wire with good connections to avoid voltage drop issues.
E02 – Over Voltage
What it means: Your heater is getting too much voltage, usually when your engine’s running and the alternator is charging.
How to fix it:
- Check your voltage while the engine is running. Over 14.5V consistently? You might need a voltage regulator
- Double-check your heater wiring isn’t accidentally tapped into a charging circuit
- Some cheap alternators can spike voltage – worth checking if this coincides with engine running
E03 – Glow Plug Fault
What it means: The heater can’t create the spark needed to ignite the fuel, usually due to a carbon-clogged or faulty glow plug.
How to fix it:
- Remove and inspect the glow plug (it unscrews from the combustion chamber)
- If it’s black and crusty with carbon buildup, clean it with fine sandpaper or replace it entirely
- Check all connections to the glow plug – a loose wire here will drive you mad with intermittent faults
- Personal experience: I’ve found cheap glow plugs last about 6-8 months of regular use, so keep a spare handy
E04 – Fuel Pump Disconnected
What it means: The heater isn’t getting fuel because the pump isn’t connected properly or there’s a wiring fault.
How to fix it:
- Check that the fuel pump connector is properly clicked into place (sounds obvious, but vibration can work these loose)
- Inspect all fuel pump wiring for damage or corrosion
- Low battery voltage can also cause the pump to fail, so check that first
- Quick test: You should hear the fuel pump ticking when the heater tries to start
E05 – Overheat
What it means: The heater is running too hot because it can’t breathe properly.
How to fix it:
- Check that your air intake (usually under the van) isn’t blocked with leaves, mud, or snow
- Ensure your exhaust isn’t obstructed – even partially blocked exhausts cause overheating
- Look for crushed or kinked heating ducts inside your van
- Van life hack: If you’ve been running on low power for weeks, blast it on high for 10-15 minutes occasionally to burn off carbon deposits
E06 – Fan Motor Fault
What it means: The internal fan isn’t spinning properly, almost always due to low voltage.
How to fix it:
- Check battery voltage first – weak batteries can’t spin the fan properly
- Look inside the heater (when cool!) for any obvious obstructions around the fan blades
- This error often appears alongside E01, so fix your power issues first
E07 – Communication Error
What it means: The controller on your wall isn’t talking to the main heater unit.
How to fix it:
- Unplug and reconnect the cable between controller and heater
- Check the cable isn’t damaged or pinched somewhere in your van’s structure
- Try a full system reset by turning everything off for 10 minutes, then restarting
E08 – Low Fuel or Air in Fuel Lines
What it means: The heater isn’t getting enough fuel, often after running the tank dry or due to air bubbles in the system.
How to fix it:
- Make sure your fuel tank isn’t empty (yes, really – we’ve all been there)
- Prime the fuel system by running the pump several times to clear air bubbles
- Check and clean your fuel filter if fitted
- Important: After running out of fuel, expect to restart the heater 3-4 times before it fully primes and runs normally
E10 – Multiple Restart Failures
What it means: The heater has tried to start several times and failed, so it’s given up trying.
How to fix it:
- Work through all the above errors and fix any underlying issues first
- Clear the error and restart the heater
- Be patient – if you’ve had fuel issues, it might take several restart attempts to fully clear the system
- Crucial: Don’t turn it off mid-cycle. Let it run through its complete startup or shutdown sequence
Prevention is Better Than Cure
Want to avoid most of these headaches? Here’s what actually works:
Monthly maintenance:
- Clean your air intake and check exhaust isn’t blocked
- Check battery voltage and charging system
- Run the heater on full power for 15 minutes to burn off carbon
Before winter:
- Replace the glow plug if it’s over a season old
- Check all electrical connections are clean and tight
- Test run the heater before you really need it
Never:
- Let your fuel run completely dry
- Turn off the heater mid-cycle (let it complete its shutdown)
- Block air intakes or exhausts with gear
When All Else Fails
If you’ve worked through this list and you’re still getting errors, don’t despair. Chinese diesel heaters are actually pretty robust, and most “unfixable” issues come down to worn-out components rather than fundamental failures.
The most common culprits for persistent problems are old glow plugs, corroded connections, or fuel system contamination. Sometimes the cheapest fix is just replacing the glow plug and giving all your electrical connections a proper clean.
Keep a basic spares kit: spare glow plug, fuel pump, and some extra wire. These heaters might be budget kit, but they’ll keep you warm through the worst weather if you show them a bit of TLC.
Stay warm out there, and drop a comment if you’re wrestling with a particular error – the van life community is always ready to help troubleshoot!
*Have you dealt with any of these errors?
