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Electric tankless water heater VS Gas hot water tank?

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Oct 16, 2014
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North York, ON

Electric tankless water heater VS Gas hot water tank?

Say for the same small house (1 bathroom, 2 toilets, 1 kitchen, 1 washing machine). Will the electric tankless SIGNIFICANTLY raise the HYDRO BILL, over the gas bill of the hot water tank?

When installing an electric tankless, is it the same HVAC guy who will do the electrical, or will it be a separate electrician?

For those with experience changing their Gas hot water tank to tankless Electric or Gas, how much did it cost you?
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Feb 11, 2007
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Yes, electric heater only makes sense if you live in Quebec where electricity is cheap. Gas is significantly cheaper in Ontario for heating (air or water).
Your only consideration should be what type of gas heater to get (tankless, vs powervent tank, vs non-powervent tank).
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Dec 9, 2009
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I went from a power vented gas tank to gas tankless myself. Bought the tankless, and had a company install. I was totally nailed on the install cost (because I didn't buy the unit from the installer). In hindsight, I would probably stick with a power vent gas tank, avoid electric (esp. in Ontario). The tankless is great from a "more space" perspective, but first impressions from an energy-saving perspective is that little energy is being saved by going to the tankless (despite claims that you'll save). I personally don't know much about electric tankless myself, but given the choice between gas or electric tankless, I would go gas. You'll likely save money in the long run versus electric.
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Jun 11, 2010
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buliwyf wrote: Say for the same small house (1 bathroom, 2 toilets, 1 kitchen, 1 washing machine). Will the electric tankless SIGNIFICANTLY raise the HYDRO BILL, over the gas bill of the hot water tank?

When installing an electric tankless, is it the same HVAC guy who will do the electrical, or will it be a separate electrician?

For those with experience changing their Gas hot water tank to tankless Electric or Gas, how much did it cost you?
My old place had a powervent natural gas 40gal water heater tank (brand new), and my new place has an electric 40gal tank (17 years old). My old Hydro usage was about $65/month, my new usage is about $95/month. Now, to be fair the place is a little bit bigger, probably 200sqft, and probably less efficient so the furnace runs more often. Not only that but the GF likes to cook whenever regardless of hydro rates, and we've started using a slow cooker and dishwasher. So let's say it's about a $20 increase. I don't think the natural gas usage has dropped by that much as I'd previously pay $80/month for about 8 months and then nothing for the last 4 because Enbridge owed me money. So when I replace my tank I think I'll be going with natural gas, depending on how much I'd get charged to run a line over from the furnace.
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You need to have an enormous electric service to handle a tankless electric heater, plus all the other stuff in your home.

Stick with gas. With a quality power vent tank, you'll use about 0.8-1m3 of gas per day to heat hot water, which works out to $80 or $90 a year.
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Feb 8, 2014
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Electricity will costs about 5x what gas will.
In fact in Rand McNally they wear hats on their feet and hamburgers eat people
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Apr 20, 2011
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engineered wrote: Yes, electric heater only makes sense if you live in Quebec where electricity is cheap. Gas is significantly cheaper in Ontario for heating (air or water).
Your only consideration should be what type of gas heater to get (tankless, vs powervent tank, vs non-powervent tank).
Yes.*

*Only if you already have other gas appliances. It might not be worth it for hot water alone when you pay $25 service fee and $5 gas. Better off to just pay $30 hydro in that case.

Electric tankless - don't bother unless you have a spare 100A and only use hot water off peak.
Only tankless to consider is gas.
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Jan 25, 2007
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Quentin5 wrote: Electricity will costs about 5x what gas will.
BTU to BTU of electric:gas I think it's closer to 10:1
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Jerico wrote: BTU to BTU of electric:gas I think it's closer to 10:1
1m3 of natural gas contains about 10.5kW, determine its cost (including delivery and fees) and compare to electricity which is about 20c/kWh (off peak/mid peak/peak averaged). Remember to assume about 75% efficiency, combustion efficiency and standby losses.
It works out to about 5x.
In fact in Rand McNally they wear hats on their feet and hamburgers eat people
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Quentin5 wrote: 1m3 of natural gas contains about 10.5kW, determine its cost (including delivery and fees) and compare to electricity which is about 20c/kWh (off peak/mid peak/peak averaged). Remember to assume about 75% efficiency, combustion efficiency and standby losses.
It works out to about 5x.
11 cents for 40k BTU vs $1.10. 10:1.
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aqnd wrote: Yes.*

*Only if you already have other gas appliances. It might not be worth it for hot water alone when you pay $25 service fee and $5 gas. Better off to just pay $30 hydro in that case.

Electric tankless - don't bother unless you have a spare 100A and only use hot water off peak.
Only tankless to consider is gas.
Maybe if OP is a single guy who likes cold showers and is paying a fortune for electric heat. Otherwise electric water heater is going to cost way more than $30 for a typical family.
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Jerico wrote: 11 cents for 40k BTU vs $1.10. 10:1.
You gotta be kidding :facepalm:

According to here the current price for natural gas per cubic meter is 25.6823c/m3
so 10.5kWh costs 2.45 cents times 75% efficiency (tank loses, burner efficiency) is ~3.3 c/kWh. Condensing tank assumed, if you use non condensing then the cost is higher meaning more per kWh strengthening my argument. I also assumed a house using natural gas for heating at the average rate, if its natural gas only for the water its a higher delivery charge plus the monthly charges you would not otherwise have. So i am working in your favour 3x in my assumptions.
Electricity costs about 20c/kWh averaged. If most of the heating is done in off peak then lower electricity cost, closer to 15c/kWh (tankless after all), again strengthening my argument.
So with a total of 4 assumptions working in your favour it makes 6.06x not 10x
In fact in Rand McNally they wear hats on their feet and hamburgers eat people
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Quentin5 wrote: You gotta be kidding :facepalm:

According to here the current price for natural gas per cubic meter is 25.6823c/m3
so 10.5kWh costs 2.45 cents times 75% efficiency (tank loses, burner efficiency) is ~3.3 c/kWh. Condensing tank assumed, if you use non condensing then the cost is higher meaning more per kWh strengthening my argument. I also assumed a house using natural gas for heating at the average rate, if its natural gas only for the water its a higher delivery charge plus the monthly charges you would not otherwise have. So i am working in your favour 3x in my assumptions.
Electricity costs about 20c/kWh averaged. If most of the heating is done in off peak then lower electricity cost, closer to 15c/kWh (tankless after all), again strengthening my argument.
So with a total of 4 assumptions working in your favour it makes 6.06x not 10x
75% is a hefty loss for a water heater. Maybe on a stove. So let's go back to raw power at 2.45 cents since electric tanks have energy losses as well.

My average electricity usage 2 years ago was 18.4 cents. I don't think you can buy electricity for 15 cents in this province right now.

So I'll settle on 7.5 times which is dead nuts in the middle.
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Jerico wrote: 75% is a hefty loss for a water heater. Maybe on a stove. So let's go back to raw power at 2.45 cents since electric tanks have energy losses as well.

My average electricity usage 2 years ago was 18.4 cents. I don't think you can buy electricity for 15 cents in this province right now.

So I'll settle on 7.5 times which is dead nuts in the middle.
25% loss, as in 75% efficient. Feel free to check your electricity prices here
http://www.ontarioenergyboard.ca/OEB/Co ... ty+Utility
Be sure to start with zero to subtract fixed cost and adjust TOU percentages, you can use hot water off peak and save (assuming you work). Also this thread is about tankless, but if you want to burn more expensive electricity...
In fact in Rand McNally they wear hats on their feet and hamburgers eat people
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Jan 25, 2007
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Quentin5 wrote: 25% loss, as in 75% efficient. Feel free to check your electricity prices here
http://www.ontarioenergyboard.ca/OEB/Co ... ty+Utility
Be sure to start with zero to subtract fixed cost and adjust TOU percentages, you can use hot water off peak and save (assuming you work). Also this thread is about tankless, but if you want to burn more expensive electricity...
why not say 65% efficient to support your alternative facts? Or 55%?
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May 12, 2014
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Quentin5 wrote: Electricity costs about 20c/kWh averaged.... it makes 6.06x not 10x
So even at Quebec's rate of 4 cents a Kw/H it still seems cheaper to heat with gas? And yet, from my observation, many people around here have air and water heating with electric systems.
Wonder if it's worth it to convert a currently fully electric system to gas.
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FrancisBacon wrote: So even at Quebec's rate of 4 cents a Kw/H it still seems cheaper to heat with gas? And yet, from my observation, many people around here have air and water heating with electric systems.
Wonder if it's worth it to convert a currently fully electric system to gas.
Electric heaters are also cheaper to buy, install and maintain.
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FrancisBacon wrote: So even at Quebec's rate of 4 cents a Kw/H it still seems cheaper to heat with gas? And yet, from my observation, many people around here have air and water heating with electric systems.
Wonder if it's worth it to convert a currently fully electric system to gas.
This is like the gas guzzling cars and trucks from a few years ago. Fuel at the pumps was very cheap so there wasn't a need to upgrade to more efficient vehicles. As fuel prices got higher, people made the switch. The major Electric to NG switch happened in Ontario in the 70s. Electric cost went up, cheap NG showed up. The Ontario govt had programs to subsidize the switch-over cost for existing homes back then.

The cost to switch over might be holding people back in Quebec. As long as Quebec has cheap and abundant Electricity it's hard to justify.

Gas hardware usually have a higher upfront cost over electric and need specialized licensed contractors to install(at least in Ontario), I know Quebec has more lax policies on who can install or work on electrical hardware.
Gas dryers cost around $300 more for hardware and install; 10 baseboard electric heaters are almost 50% cheaper then a furnace; 3 heat pumps are cheaper then furnace + a/c + ductwork etc

I used 1571 m3 of NG last year(Gas Dryer, water heater, Cooking (Stove & BBQ), heating (Firplace and Furnace). Acoordring to the Estimate on Gazmetro, if I lived in Quebec my cost in NG would have been $888, Electric $1438.

An estimate savings of $5500 over 10 years will hardly cover the cost to switch all my consumption to NG. If I plan to upgrade houses then I'd not even consider it.
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bubuski wrote: This is like the gas guzzling cars and trucks from a few years ago. Fuel at the pumps was very cheap so there wasn't a need to upgrade to more efficient vehicles. As fuel prices got higher, people made the switch. The major Electric to NG switch happened in Ontario in the 70s. Electric cost went up, cheap NG showed up. The Ontario govt had programs to subsidize the switch-over cost for existing homes back then.

The cost to switch over might be holding people back in Quebec. As long as Quebec has cheap and abundant Electricity it's hard to justify.

Gas hardware usually have a higher upfront cost over electric and need specialized licensed contractors to install(at least in Ontario), I know Quebec has more lax policies on who can install or work on electrical hardware.
Gas dryers cost around $300 more for hardware and install; 10 baseboard electric heaters are almost 50% cheaper then a furnace; 3 heat pumps are cheaper then furnace + a/c + ductwork etc

I used 1571 m3 of NG last year(Gas Dryer, water heater, Cooking (Stove & BBQ), heating (Firplace and Furnace). Acoordring to the Estimate on Gazmetro, if I lived in Quebec my cost in NG would have been $888, Electric $1438.

An estimate savings of $5500 over 10 years will hardly cover the cost to switch all my consumption to NG. If I plan to upgrade houses then I'd not even consider it.
From what someone said in another thread electricity is about 7c kWh in Quebec after all fees, which is a bargain compared to Ontario but still double the natural gas. Also not everyone has natural gas hookups to their house.
That said eventually we will have to retire natural gas as we fight climate change, and heat pump water heaters that run on have a COP of about 3 (think A/C in reverse to heat water) though they are not commonly available yet and probably not as reliable as the standard electric resistance. I hope in the future there are also incentives for switching.

Jerico wrote: why not say 65% efficient to support your alternative facts? Or 55%?
I'm getting sick of this, if you don't like math then whats the point in arguing?
In fact in Rand McNally they wear hats on their feet and hamburgers eat people
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Jan 25, 2007
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Quentin5 wrote:
I'm getting sick of this, if you don't like math then whats the point in arguing?
I don't like your made up assumptions.

Natural gas generates a lot of power in Ontario at the moment.

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