electric immersion water heater power consumption

If you are planning to buy a new electric immersion water heater or wondering how much electricity your existing immersion heater is consuming then this article is for you. In this article, we will calculate the power consumption of an immersion water heater and also look at how much it costs to use one.

Also by the end, you will learn to calculate the power consumption of any electric immersion water heater using a simple calculator.

Electric immersion heaters are normally rated between 300 watts to 1500 watts. A 1000 watts immersion heater running for 10 minutes in a day will consume around 0.167 kWh of electricity in a day. This adds up to around 5 kWh of electricity in a month.


Immersion Water Heater Power Consumption:

The power consumption of an immersion water heater (for that matter any electrical appliance) depends upon two main things

  1. First is the wattage of your immersion water heater,
  2. And second is the electricity tariff in your area.

Before we jump into calculating the power consumption of your immersion water heater let’s see what these terms are and how you can find out your electric immersion water heater wattage and the electricity tariff of your locality.

If you already know these terms and just want to use the calculator then please scroll down to use the calculator.


What is the Wattage of an Electric Immersion Water Heater:

electric immersion water heater wattage
600 Watt Immersion Water Heater

The wattage of an electric immersion heater varies from 300 watts to 1500 watts.

You can find the wattage of your immersion water heater by reading on the label in it or just look for your immersion water heater on amazon and you will find its wattage in the description section.

(If you don’t have time to do this, then don’t worry I have put together a table at the end that shows the power consumption of a range of immersion water heaters with different wattages.)

If you don’t know what a watt is then here it is,

Watt is the unit of power. It means the rate at which electricity is consumed or produced by a device. For example, a 50-watt TV consumes power at a rate of 50 watts per hour, it does not mean that the TV consumed 50 units of electricity, it means it will consume power at a rate of 50 watts every hour.

So in short, the wattage of an electric immersion water heater lies between 300 watts to 1500 watts and you can find it by looking at the label on it. With that out of the way, let’s look at what is electricity tariff.


What is your Electricity Tariff:

In simple words, an electricity tariff is the amount your electricity provider charges you for one unit (kWh) of electricity. I live in Mumbai, India here the electricity tariff is Rs 12/kWh.

(What is a Kilowatt hour (kWh) Kilowatt hours or units of electricity is the energy consumption of a device. For example, a 50-watt table fan running for 50 hours will consume 50 watts x 50 hours = 2500-watt hours = 2.5-kilowatt hours of electricity = 2.5 units of electricity. (1 kWh of electricity = 1 unit of electricity))

To find your electricity tariff, just look into your previous month’s electricity bill and find out your monthly electricity consumption, then just divide your monthly electricity consumption by your total monthly electricity bill, the figure you get is approximately your electricity tariff.

If you don’t want to do any of this then just google electricity tariff followed by your location.


Calculate electric Immersion Water Heater Power Consumption:

With these two pieces of information in hand, you are ready to find the power consumption of your immersion water heater.

immersion water heater rod wattage
1500 Watt Immersion Water Heater

Let me show you an example,

I have selected a 1500-watt electric immersion water heater listed on amazon. Let’s assume we will be using it for 10 minutes every day throughout the year.

Hence, we will calculate the power consumption of this 1500 watts immersion water heater in a day, in a month, and in an entire year.

With the knowledge of your immersion water heater wattage and your electricity tariff, just use this simple formula to calculate power consumption.

Power consumption of a 1500-watt immersion water heater = Wattage of the immersion water heater X operational hours

Cost to run a 1500-watt immersion water heater = Power consumption of the immersion water heater X electricity tariff.

(Operational hours is basically the number of hours you are using your immersion water heater)

Now let’s calculate


Electricity consumption of A 1500 Watt Immersion Water Heater:

In our case, wattage is 1500 watt and operational hours is 10 minutes (0.167 hours) in a day, 5 hours in a month, and 60.83 hours in a year.

Hence by using the above formula.

Power consumption of a 1500-watt immersion water heater in a day (10 minutes) = 1500 watts X 0.167 hours = 0.25 kilowatt hours (kWh)

Similarly, the power consumption of a 1500-watt immersion water heater in a month (5 hours) = 1500 watts X 5 hours = 7.5 kWh

And Power consumption of a 1500-watt immersion water heater in a year (60 hours) = 1500 watts X 60 hours = 90 kWh

Now that we know the power consumption just multiply it by your electricity tariff and you will get how much it will cost you to run your electric immersion water heater.

let’s calculate how much it will cost to run this 1500 watts immersion water heater for an entire day in Los Angeles, London, and in Mumbai.

  • In case of Los Angeles, the electricity tariff in Los Angeles is around 25.8 cents per kilowatt hour (kWh), hence it will cost around $ 1.94 (7.5 kWh X 25.8 cents) to run this 1500 watts immersion water heater for 10 minutes every day for an entire month.
  • In case of London, the electricity tariff in London is around 36p/kWh, hence it will cost around £ 2.7 (7.5 kWh X 36p/kWh) to run this 1500 watts immersion water heater for 10 minutes every day for an entire month.
  • In case of Mumbai, the electricity tariff in Mumbai is around Rs 10 per kilowatt hour (kWh), hence it will cost around Rs 75 (7.5 kWh X Rs 10) to run this 1500 watts immersion water heater for 10 minutes every day for an entire month.

For your reference, I have calculated the cost to run this 1500-watt electric immersion heater for 10 minutes daily throughout the year in Los Angeles, London and Mumbai.

Country (Tariff)Daily Power Consumption
(1500 Watt @ 10 min
)
Monthly Power Consumption
(1500 Watt @ 5 hours)
Annual Power Consumption
(1500 Watt @ 60 hours)
Los Angeles (25.8 c/kWh)0.25 kWh, cents 6.457.5 kWh, $ 1.9490 kWh, $ 23.22
London (36p/kWh)0.25 kWh, pence 97.5 kWh, £ 2.790 kWh, £ 32.40
Mumbai (Rs 10/kWh)0.25 kWh, Rs 2.57.5 kWh, Rs 7590 kWh, Rs 900

As you can see from the above table, it would cost you $23.22 (in LA), £ 32.40 (in London), and Rs 900 (in Mumbai) to run a 1500-watt immersion water heater for 10 minutes daily for an entire year.

The above figures suggest the maximum power consumption of a 1500-watt immersion water heater, however, the actual power consumption would be 5% to 10% less than this value.


Electricity consumption for different Wattage Immersion Water Heater:

For your reference, I have made the below table which shows the power consumption of a range of immersion water heaters having different wattages. I have assumed 10 minutes of operation every day for the entire month.

Immersion Water
Heater Wattage
Daily Power Consumption
(10 minutes)
Monthly Power Consumption
(300 min or 5 hours)
Annual Power Consumption
(60 hours)
300 watts0.05 kWh1.5 kWh18 kWh
750 watts0.125 kWh3.75 kWh45 kWh
1000 watts0.167 kWh5 kWh60 kWh
1500 watts0.25 kWh7.50 kWh90 kWh

You can multiply the above power consumption figures by your electricity tariff to get the final cost of using an immersion water heater.

Now go ahead and use the below calculator to find out the power consumption of your electric immersion water heater.

Just type the wattage of your immersion water heating rod, hours of usage, and your electricity tariff, and let the calculator do the math for you.


Immersion Water Heater power consumption calculator:

If you are not happy with the approximate results and want to know the exact power consumption, then I would suggest you buy a cheap Kill A Watt Meter from amazon.


Calculate The exact power consumption using Kill A Watt Meter:

Kill A Watt Meter is a simple device that gives real-time data on the power consumption of any device.

You can check it on amazon using this link – Kill A Watt Electricity Usage Monitor

To use a kill-a-watt meter to calculate the power consumption of your immersion water heater, first, connect your immersion water heater plug into the kill-a-watt meter and then plug the kill-a-watt meter in your wall socket and you are good to go.

Then start using your water heater and you can see in real-time how many kWh (units) of electricity it is consuming.

You can check out this article to know more about the power consumption of common household appliances.

Check out my articles on solar power for home and how it can help you save your electricity bill.

Thank you for reading.

Aavjo 👋


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