How Much Power Does An Oil Heater Use?

As winter approaches in Australia, Aussies start looking for energy-efficient heaters. Among the multiple options available, oil heaters remain popular choices due to their silent operation, thermal mass, and even heat distribution. But exactly how much power does an oil heater use? Let's dive deeper to understand.

Power Consumption of Oil Heaters

The total power consumption of an oil heater mainly depends on three main factors: the heater's wattage (power draw), the duty cycle determined by your thermostat setting and room insulation, and your local electricity rate.

By combining all three factors, the average power consumption of an oil heater in Australia is typically 600–2,400Wh per hour. To better understand, let's explore how to calculate power consumption.

Firstly, the rated wattage of the device: typically 600W to 2,400W for residential models. (Note: Wattage measures power draw; energy consumption is measured in kilowatt-hours or kWh.)

Secondly, the thermostat setting and room conditions. Oil heaters cycle on and off once the oil reaches the target temperature. In a well-insulated room, the heater may only run 30–50% of the time (the duty cycle), significantly reducing actual energy use versus continuous operation.

Thirdly, the electricity cost, which is different for each region. For Australia, national averages range from 26¢ to 40¢/kWh depending on your state and retailer, with Victoria and Queensland typically on the lower end and South Australia higher. Peak time-of-use rates (usually 3 pm–9 pm weekdays in applicable states) can reach 40–50¢/kWh, while off-peak rates may drop to 10–15¢/kWh.

When combining these factors, a typical 1,500W oil heater consuming 1.5kW when running will use between 0.75kWh and 1.5kWh per hour of clock time, depending on how frequently the thermostat cycles.

How to Calculate the Power Consumption of an Oil Heater

Here is a simple and easy way to calculate the power consumption of an oil heater.

Power consumption (in kWh) = wattage (in kW) × hours used

"Wattage" indicates the heater's power draw when the element is active. You can find this on the manufacturer's label. Because oil heaters cycle via thermostat, the actual running time is usually less than the clock time the device is plugged in. "Hours used" refers to the time the heating element is actively drawing power, not just the time the switch is on.

Let's take an example:

A 1,500-watt oil heater is used for 60 minutes. What could be the power consumption?

First, convert the watts to kilowatts and minutes to hours. So 1,500 watts will become 1.5 kW, and 60 minutes will become 1 h.

Power consumed = 1.5kW × 1 hour = 1.5kWh.

Now, to calculate the bill's cost, we need to multiply it by the electricity cost, which is, on average, 33c/kWh in Australia.

1.5 kWh × 33c/kWh = 49.5c per hour or $0.495 per hour.

For daily usage (5 hours):

5 × $0.495 = $2.475 per 5 hours

For monthly usage (150 hours):

150 × $0.495 = $74.25 per month.

For the winter season in Australia (450 hours or 90 days):

450 × $0.495 = $222.75 per winter season

This means many Australians spend around $74 per month or $223 per winter season on an oil heater, depending on local rates. Note: These are estimates; actual costs vary with usage and rates.

In real-world conditions with proper thermostat cycling, expect 30–50% lower costs than these continuous-operation figures. Many Australian households spend approximately $40–$100 per month during winter, depending on insulation, climate zone, and usage patterns.

Factors Affecting the Power Consumption Of Oil Heaters

Factors that affect the power consumption of an oil heater are:

Incorrect Sizing

Heater sizing significantly impacts efficiency. Choosing a small-sized heater for a big area could cost more in total energy use because it will keep running continuously without reaching the thermostat setpoint, never achieving the duty cycle that saves power. Conversely, an oversized heater cycles frequently, which is also inefficient. A room with a 20 m² area typically requires 1,000–1,500W, while larger open-plan spaces may require 2,000W or more.

Home Design and Layout

Home design also plays an important role in power consumption. High ceilings, large windows, and open-plan designs increase heat loss. Standard ceiling heights (2.4m) with closed doors retain heat more effectively than cathedral ceilings or drafty floorplans.

Lack of Proper Insulation

A home with proper insulation, like cellulose, fiberglass, or foam, keeps the heat for a longer time. Make sure you install the insulation in walls, roofs, and floors. Without adequate insulation (minimum R2.5 in walls, R4.0+ in ceilings for southern states), any heater will run continuously regardless of type.

Usage Timing and Tariffs

Using it during peak time costs more, especially in Australia, where peak times vary from state to state (for example, 2 pm–8 pm in NSW/Victoria on weekdays, or 4 pm–8 pm in QLD), but off-peak rates (typically 10 pm–7 am) offer significant savings where time-of-use pricing applies.

Tips To Increase the Efficiency of Oil-Filled Heaters

Here are a few important tips that will improve the efficiency and reduce the expenses of the oil heater.

Opting for the Right Oil Heater

Check out your living or office area before buying a heater. If it is up to 20m², go for 1–1.5 kW. If the space is larger or poorly insulated, then go for a higher capacity unit or improve the insulation first. Undersizing is the most common cause of excessive running costs.

Install in an Enclosed Space

By 'enclosed space', we mean a space where there is a lower chance of air exchange with the outdoors, such as a well-sealed living room or office. Avoid placing oil heaters in drafty hallways or near frequently opened external doors, heaters in drafty hallways or near frequently opened external doors, as the thermal mass cannot overcome rapid air changes.

Using an Upgraded Thermostat

Using an upgraded thermostat with a proper on/off cycle significantly improves the efficiency of the oil heater. It allows you to set a specific temperature schedule and avoid unnecessary heating.

Insulation and Draught Seal

Heaters do not work efficiently when heat is lost through poor insulation, windows, and doors. Replacing drafty seals with good insulation and weatherstripping for windows and doors will increase the heater's efficiency. Even heavy curtains can reduce heat loss through glass by 25%.

Safety Considerations

Oil heaters, while generally safe, require proper clearance (minimum 1 metre from curtains, furniture, and bedding). Never drape clothing over the unit to dry—this poses a significant fire risk. Ensure the unit has a tip-over switch (mandatory for new units in Australia) and place it on a flat, stable surface away from high-traffic areas where it could be knocked over. Check the power cord annually for fraying, as damaged cords can overheat.

Annual Maintenance

Maintenance for oil-filled heaters is minimal compared to gas or combustion systems. Unlike oil-burning furnaces, these electric units contain sealed diathermic oil that never requires changing—it circulates passively for the lifetime of the unit (typically 10–15 years). Instead, maintenance involves:

• Dust removal: Vacuum the fins and convection ports annually to prevent dust-burning smells and ensure efficient airflow.
• Wheel and stability check: Ensure casters move freely and the unit sits level to prevent oil stratification or noise.
• Electrical inspection: Have a qualified electrician check the cord and plug if the unit is over 5 years old or shows signs of heat damage.

The previous mention of "changing oil" referred to combustion furnaces and does not apply to electric oil-filled radiators.

Avoid Using During Peak Hours

Avoid using the oil heater during peak hours because it will cost you more. But if you still want to use it in peak hours, then you must use a portable power supply with it.

To help, here's a quick table of peak times by state:

Best Portable Power Backup For Heaters

Once you have decided to use the heater during peak time, it's time to invest in a portable power source. Load shifting—storing energy during cheap off-peak rates or solar generation for use during expensive peak periods—is the primary economic benefit of pairing heaters with battery systems.

For a small area or low-wattage operation (600–1,000W), the BLUETTI Elite 200 V2 Portable Power Station is a good option. It comes with a 2,073 Wh capacity, which can power a 1,000W heater for approximately 1.5–2 hours, or a 600W eco-setting heater for over 3 hours—sufficient to bridge the expensive evening peak period (e.g., 5 pm–8 pm).

But if you want to use a large oil heater (2,000–2,400W) for extended periods, or require whole-room heating overnight, then we recommend the BLUETTI Apex 300 Versatile Power Station. It comes with a base capacity of 2,764.8Wh (2.7kWh), expandable up to 11.5kWh with additional battery modules. At 2.7kWh, it powers a 1,500W heater for approximately 1.5–2 hours of continuous operation, or 3–4 hours with normal thermostat cycling. When expanded to full capacity, it can provide 7–10 hours of heating support, ideal for off-grid cabins or grid-failure backup during cold snaps.

A Portable Power Station may seem expensive, but it's a good investment for the long run. For example, charging at 10¢/kWh off-peak and discharging during 45¢/kWh peak effectively saves 35¢ per kWh used—potentially $50–$100 per month during winter for heavy users. Pairing with solar panels can reduce bills significantly, which can recover the investment in a few years. They are also beneficial in an area with power outages. Additionally, they are portable, so you can easily move them to your office, workshops, or on a trip.

Oil-Filled Heater Vs Other Heaters

There are multiple types of heaters on the market. To buy one, you must check out its power consumption and other features.Here is a comparison of some heaters, including an oil heater. It will make it easy for you to buy one for yourself.

Costs are similar, but oil-filled heaters take the advantage with their long-lasting heat.

What Makes an Oil Heater More Efficient Than Others?

Top 7 reasons you should buy oil heaters instead of others.

• Retained heat after power cycles off (thermal mass)
• Completely silent operation (no fan)
• Even heat distribution through convection
• Do not dry the air or circulate dust
• Ideal for long use and overnight heating
• Neutral aesthetic design suits most decors
• Safe for allergy sufferers (no forced air)

Frequently Asked Questions

Do oil heaters use a lot of electricity?

No, oil heaters do not use a lot of electricity compared to other heaters due to their thermal oil reservoir. At the start, it may use energy to get warm, but once the room temperature reaches the set temperature, the thermostat turns off the power and uses the thermal oil to store heat for heating.

How much does it cost to run a 2000-watt heater for 24 hours?

Running a 2000-watt heater will cost $15.84 for running 24 hours continuously. It is calculated by multiplying the watt in kW by the time in hours and the electricity cost. For Australia, the electricity cost averages 33c/kWh or $0.33/kWh. So power consumption will be 2kW × 24h × $0.33 = $15.84.

Which oil is used in an oil heater?

Oil-filled heaters use diathermic oil that transfers heat energy. Diathermic oil is also stable at high-grade temperatures, which is why it is used in heaters.

How much electricity does an 11-fin 2400-watt electric oil heater use?

A 2400W electric oil heater with 11 fins will use the same energy as the other 2400W oil heaters because fins affect heat distribution, not power consumption.

Conclusion

The short answer to "how much power does an oil heater use?" is that the power consumption of oil-filled heaters varies depending on the device, timing, and electricity cost. The average power consumption for a common heater, which is 1,500 watts, is 7.5 kWh over 5 hours and costs $2.48 at 33c/kWh, which can be more expensive during peak hours. However, with proper thermostat cycling in an insulated room, actual consumption and costs are typically 30–50% lower.

But using it with a portable power source such as the BLUETTI Apex 300 Versatile Power Station (for big heaters) or the BLUETTI Elite 200 V2 Portable Power Station (for small heaters) will help reduce expenses and potentially recoup costs within a few years.

Ready to save on your winter bills? Explore BLUETTI options today for peak-hour and off-grid power solutions.