"I just bought 18L of kerosene, but it's already running low." As it gets colder, this concern often arises. The first things to check are not additives, but the set temperature, operating time, room insulation, and the condition of the appliance. Let's break down the reasons why you might feel your kerosene consumption is high, step by step.
Conclusion: Kerosene consumption varies significantly with heating output
Some kerosene fan heaters have fuel consumption rates that change based on the heating intensity. According to published specifications for the Corona FH-CPF33A, it consumes approximately 0.321 L/h on high and approximately 0.061 L/h on low. Please note that this is specific to this model and does not apply to all heaters. First, please check the fuel consumption in the instruction manual for your specific model.
1. Try lowering the set temperature by just 1°C
Attempting to maintain a high set temperature tends to keep the heater running at high intensity for longer. According to energy-saving information from the Agency for Natural Resources and Energy, based on specific trial conditions (6°C outside temperature, 9 hours of use per day), lowering the set temperature from 21°C to 20°C can reduce annual kerosene consumption for a fan heater by approximately 10.22L. Actual savings will vary depending on the equipment, housing, and temperature. Try lowering it by 1°C first, and if you feel cold, use extra clothing or focus on keeping your feet warm.
2. Track your operating time for one week
Keep a note for just one week of how many hours you have the heater on in the morning, evening, and night. Also, check if you are leaving it on until just before you go out or go to sleep. Always turn it off when you leave the house or go to bed. The fundamental rule is never to leave the room while the heater is running.
3. Check if heat is escaping through windows or doors
Cold air from windows, drafts, or frequently opened doors will force the heater to continue burning to maintain the room temperature. Check your curtains, floor insulation, and measures against drafts. However, blocking ventilation ducts or sealing a room airtight is dangerous. Open-type combustion heaters require proper ventilation.
4. Clean the filters
If dust accumulates on the intake filter, the heater cannot perform at its full heating capacity. After turning off the heater and letting it cool down thoroughly, clean it according to the instruction manual for your model. Avoid DIY disassembly or adjustments to the combustion chamber or safety devices. It is also important not to place laundry or furniture too close to the air outlet.
5. Compare room size with heater capacity
If the room is large, the ceilings are high, or insulation is poor, the heater may remain in high-intensity operation. Compare the recommended floor area for wooden or concrete structures with the actual conditions of your room. If you are comparing your usage to last year, ensure that the temperature, the room being used, and the operating time are the same.
6. Stop use and inspect if there are strange odors, white smoke, soot, or if it shuts off
If you are simply concerned about the rate of kerosene consumption, you can review your usage conditions. However, if you notice symptoms such as a strong, unusual odor, white smoke or soot, failure to ignite, frequent mid-operation shut-offs, or persistent errors, that is a different matter. Stop using the device, ventilate the room, and follow the instructions in the manual for troubleshooting. If the situation does not improve, contact the manufacturer or dealer for an inspection.
The National Institute of Technology and Evaluation (NITE) urges caution regarding carbon monoxide poisoning due to lack of ventilation. When using open-type kerosene fan heaters or kerosene stoves, ventilate the room once or twice an hour for 1–2 minutes at a time. If you feel unwell, stop using the device immediately, move to a safe location, and seek emergency medical attention if necessary.
Related article: Causes of unpleasant odors or white smoke from kerosene fan heaters
Related article: Can you use last year's kerosene? Criteria for old kerosene
7. Consider GERHON for Kerosene only after confirming your kerosene and equipment are normal
Once you have checked your operating conditions and equipment status, and are using standard kerosene properly, GERHON Fuel Conditioning for Kerosene is available as a fuel care option. The specified dosage is 9mL per 18L of kerosene, or 10mL per 20L. It is available in 200mL and 1L bottles.
However, please check your equipment's manual and the manufacturer's specifications before use. Do not use this in equipment where additives are not permitted. GERHON is not intended to fix malfunctions or regenerate degraded kerosene. We do not guarantee any improvement in kerosene consumption or heating duration. Please judge the necessity of this product based on its cost and your needs.
Related article: How many mL of GERHON for 18L of kerosene?
Related article: Capacity and cost comparison for GERHON for Kerosene
Things you can try starting today
First, try recording your "set temperature," "usage time," and "number of days to use up 18L" for one week. Instead of relying on a sense of comparison with last year, confirming your usage with numbers is the shortest route to reducing wasteful spending. If there are no abnormalities, review your settings in the order of set temperature, operating time, filter, and insulation.
Check usage conditions and capacity for GERHON for Kerosene
Reference Materials
Content verified as of October 17, 2026.