Boiler electricity consumption is one of the most important factors to be considered when choosing a boiler. It is necessary for you to know how much energy your boiler consumes. In this article, we’ll walk you through a step-by-step process to calculate the electricity consumption of your boiler. And help you make informed decisions about what type of boiler to buy.

Step 1: Determine the electrical load

The first step in calculating the boiler’s electrical consumption is to determine the electrical load. The electrical load is the amount of electricity used by the boiler and it is measured in kilowatts (kW). It depends on several factors:

The size of your boiler and its type (gas or oil or electricity). This information can typically be found on a sticker attached to your unit.

The efficiency rating of your heating system (if applicable). If you have an older system, it may not have been rated yet. However, there are ways for you to approximate their efficiency levels based on factors such as age and condition.

Building heating needs (e.g., number of rooms)

For example, if you have an 80-gallon hot water tank. And use 30 gallons per day on average during wintertime (when temperatures stay below 50 degrees Fahrenheit). Then an 80 kW boiler will be able to meet your needs without any problems.

Step 2: Convert electrical load to BTU/hour

The next step is to convert the electrical load to BTU/hour. First, you need to know:

1 kW = 3,413 BTU/h (rounded up)

For example: If you have an electric water heater with a capacity of 50 kW, then this would equate to approximately 50 * 3,416 = 170,650 BTU/hr.

Step 3: Determine the theoretical boiler efficiency

Boiler efficiency is a crucial factor in calculating electricity consumption. It is calculated by dividing the heat output by the fuel input. It represents the percentage of energy that the boiler can convert into useful heat.

Theoretical Boiler Efficiency = [(Heat Output – Heat Losses)/Fuel Input] x 100%

For example, if you have a boiler that produces 40 million Btu per hour and uses 14,000 pounds of coal per hour, then its theoretical boiler efficiency is: 40 Million Btu / 14000 Pounds = 2.93 Million BTU/Pound of Coal (or 93%)

Step 4: Calculate energy use in kilograms/kWh

This is the most important step and will determine how much you pay for your boiler each year. You can do this by multiplying the BTU/hour by your boiler efficiency. The formula is:

Energy use in kilograms/kWh = BTU/hour x boiler efficiency

For example, if your boiler uses 10,000 Btu/hr and has an efficiency of 80%, then its kWh will be 833 kWh per month:

10,000 Btu/hr x 0.8 = 833 kWh / month


Which furnace uses electricity?

An electric furnace uses electricity as its power source. Electric furnaces have heater coils made of nickel-chromium that produce heat when electricity is supplied to them. They also have a thermostat that regulates the heat and controls when the heating elements turn on or off based on your demand.

How much electricity does a boiler use?

A small residential gas or electric boiler might consume around 4-8 kWh (kilowatt-hours) per hour of operation, while larger commercial or industrial boilers may consume more electricity.

How much electricity does an electric boiler use per year?

A small residential electric boiler with a power rating of around 10-15 kW might consume anywhere between 2,000 to 4,000 kWh per year in typical use. Larger electric boilers or those used in commercial or industrial settings can consume significantly more electricity.

How much electricity does an oil furnace use?

On average, a residential oil furnace may consume around 300 to 600 kWh of electricity per year. The exact electricity usage of an oil furnace can vary depending on factors such as the furnace’s size, efficiency, and frequency of use.

How much electricity does a wood boiler use?

Some wood boiler models may consume around 100 to 500 kWh (kilowatt-hours) of electricity per year for auxiliary components, while others may use less or more.


By following the above simple steps, you can accurately calculate the electricity consumption of your boiler. Understanding your boiler’s electricity usage will empower you to make energy-efficient choices, save on utility bills, and contribute to a more sustainable environment. If you want to learn about the details of boiler electricity consumption, please contact us at +0086 186-2391-5479.

About the author

About the author

Yunchong Shang

Yunchong is a seasoned boiler expert with over five years of hands-on experience in the boiler industry. He has expertise in various types of boilers, including fire-tube, water-tube, and steam boilers, while also staying up-to-date with the latest technological boiler.

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