Compare an Electric Water Heater with a Tankless

Costs of an Electric Water Heater Compared to a Tankless

First off let’s reiterate that this comparison has been done here in Ontario where electricity is not that expensive… That’s a joke; it is crazy how much we get taken advantage of…

I don’t know which tank you have and I can only make an estimate that an electric water heater will roughly use about 5000 kWh per year.  Festival Hydro in London Ontario suggests that a family of 4 will use about 375-525 kWh per month (4500-6300 kWh per year). 

Now, how much will this electricity cost? Well Ontario Hydro is good at hiding costs in their bills.  So I thought it would be most accurate to take my last bill and simply divide the cost by the total kWh’s used. 

I had a metered usage of 276 kWh’s but there is an adjustment factor of 1.085 which totals to a use of 299 kWh’s.  

I then simply took the total of the bill at $65.85 and divided the two numbers (65.85 / 299 = 0.22) giving me a final price of 22 cents per kWh

Thats really expensive for electricity, and when you multiply the kWh rate by the average kWh’s an electric water heater consumes a year you suddenly realize how expensive they are.  For those of you counting that’s over $1100 a year in electricity ($91.76 a month).  (5000 x .22 =$1100)

If anyone is questioning why my electricity bill was a bit low, It’s because I don’t use an electric water heater.


Comparing an Electric Tank to a Tankless


I used the CMHC report that stated average tankless water heater gas use is .79 m3/day.  I should note that this is the average and it could be as low as .2 and as high as 1.9 cubic meters a day.

Since I used my total electrical consumption divided by the cost for my effective rate I will do the same for my gas bill.

I used 21 m3 and was charged $25.17 which works out to $1.20 per cubic meter (25.17 / 21 = 1.198).  This is a bit skewed here since Enbridge charges me $20 a month to be a customer no matter how much natural gas I use.  Even though I’m below the average gas use for a tankless if I was one of the power users in the CMHC study using 1.9 m3 a day my bill would only rise slightly.

Here is the math on why.

25.17 – 20 = 5.17 (that actual charge for natural gas)

5.17 / 21 = 0.2462 (so effectively a rate of 24.62 cents per cubic meter)

1.9 x 30 = 57 m3 (CMHC max tankless m3 gas use per day times 30 days)

57 x 0.2462 = 14.03 (this would be the gas charge for a tankless is used a lot)

20 + 14.03 = $34.03 is what the persons bill would have been with a very high use tankless (including the Enbridge $20 customer fee).

$14.03 is the natural gas cost on a high use tankless per month! That’s 168$ a year. 




I can guarantee you that a tankless is going to cost you more to purchase and install over an electric tank but I feel I adequately proved that it will more than catch up and surpass an electric system in just a few short years.

We have had a tankless in our home for a number of years and I can say we are more than happy with its performance and reliability. 

If you are interested in getting a price on a tankless for your home we offer free consultations.  A REP will be able to assess your home and help you choose a few places the system could be installed.  With this information we can provide you with an exact quote for a tankless system and full installation.


Call Anytime: (647) 925-1930 Or Have Us Call You By Filling Out Our Contact Form



Author: John

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