Got a diesel space heater that won’t start? You might be dealing with a common cold-weather issue: fuel waxing. In this video, Shane from Fanmaster Australia walks you through how to service your diesel space heater and clear wax blockages fast — so you’re ready for winter without delays.
Why Wax Build-Up Happens in Diesel Heaters
Diesel fuel naturally contains wax. While helpful for combustion, that wax starts to crystallise when temperatures drop, especially in colder climates. This can block:
- Fuel lines
- Fuel filters
- Nozzles
You’ll often see a cloudy white or yellow residue in the fuel tank — that’s wax, and it’s likely the reason your heater won’t start or is struggling to ignite.
Step-by-Step: Fixing Wax Blockages in a Diesel Heater
⚠️ Safety First: Always turn off and unplug your heater before servicing.
1. Check & Clean the Fuel Line and Filter
- Remove the top cover (10 screws).
- Take off the side cover (opposite side to the switch).
- Unclip the fuel line from the adaptor plate and filter.
- Inspect for cracks or wax build-up. Replace if necessary.
- Remove the fuel filter from the tank. Clean and check it’s clear.
- Reassemble all components in reverse order.
2. Inspect the Airline
- Remove top and side covers again.
- Take off the rear grill.
- Unclip the airline from the motor and adaptor plate.
- Look for cracks, wear or wax build-up.
- Replace if needed and reassemble.
3. Clean the Magic Eye Sensor
This sensor detects ignition and must be clean to work properly.
- Remove the top cover.
- Carefully pull out the magic eye sensor near the spark plug.
- Wipe it clean with a soft cloth, tissue, or cotton bud.
- Reinsert and secure it.
Still Not Working?
If your heater won’t start after these checks:
- You may have a deeper fuel system or electrical issue.
- Take it to a qualified service technician.
- Never attempt to service electrical components yourself. This must be done by a licensed professional.
Tips to Prevent Future Wax Blockages
- Use kerosene or diesel to clean parts — never water.
- If water is used, ensure parts are completely dry before reassembly.
- Store heaters indoors when not in use, and cover them once cool.
- In colder areas (like alpine or inland regions), use a kerosene/diesel blend to lower the fuel’s cloud point and avoid waxing.
For recommended fuel mix ratios and other winter-ready tips, visit the Resources page.
Fanmaster: More Than Just Fans
When it comes to heating, cooling and ventilation, Fanmaster is your expert partner for commercial and industrial solutions.
👉 Need spare parts or a new diesel heater? Get in touch with us or shop online.