yes theres a better way tankless water heaters................ you could hook up the electric hot water heater and then take a calculation of what it will cost to take a shower.

It all depends on your cost of electricity in cents per KWH (killowatt- hour).
For example if your cost is , say 10 cents per KWH and oil is going to cost $5 per gallon, then I would use an electric hot water heater and perhaps consider a heat pump for heating and cooling, or other options.
Post your cost and your geographical location and we can give you an idea.

I live in the North East. I have a new oil fired boiler (1 year old), forced hot water system. It has 4 zones, one of which is for my domestic hot water tank. The boiler will only fire if the aquastat is below setpoint and there is a call from any zone, so it does not run to maintain a boiler setpoint (which is good). With the price of home heating oil averaging $4.75 a gallon, I am taking some steps to cut back on costs. One of which has been the recent purchase of a Pellet stove. I plan on this being my primary means of heating my house. I am questioning whether or not to install an electric hot water tank as my primary source of domestic hot water instead of my indirect domestic hot water tank. I have asked around, both via associates in the trade and reading the online forums. Pretty much everyone seems to believe electric hot water is cheaper. I want to believe that is true, but my calculations tell me other wise. I could be overlooking something, I sure hope so. Anyway, please review the following and advice. Thanks

Home heating oil produces about 140,000 BTU per Gal
My boiler is 84% efficient, which yields me 117,000 BTU per Gal.
Heat losses due to piping etc I cant calculate, so I will stretch a guess and say 10% heat losses. So now I yield 105,850 BTU per gallon.

Circulator pump and Burner motor running consume 2.41 amps combined, consuming .2892 KWH @ $.18415071 per kwh = $.05 an hour to run. (is that right?)

So to get the 105,850 BTUH from a gal of oil it costs me $4.75 + $.05 for pump and burner run time for a total of $4.80

Now to get the same 105,850 BTU from an electric hot water tank, and figuring electric heat at 100% efficiency ( I realize its probably more like 97% in reality).
1 KW = 3,413 BTU.
So 105,850 BTU divided by 3,413 BTU = 31.01 KW needed to produce the 105,850 BTUÂs
So 31.01 KW times the cost of $.18415071 per kwh = $5.71.

My calculations here tell me to get 105,850 BTUH from my oil burner cost me $4.80
My calculations here tell me to get 105,850 BTUH from Electric hot water tank cost me $5.71. What am I doing wrong here? Thanks

I was looking into this and went to the Central Maine Power web site and found these FAQs:
Question: I use a lot of hot water, even in the summer. Is it less expensive to heat my water in the summer with electricity than with oil?

Answer: Yes, it is less expensive to use an electric water heater than to run the boiler just for the purpose of heating water. The efficiency of an oil-fired boiler used only to heat water is lower than when it's being used to heat your house as well. Although documented data regarding this efficiency is limited, a separate oil-fired water heater has an efficiency just over 50%. A boiler would have to operate at over 65% efficiency to heat water at a lower cost than an electric water heater."

Question: I heat my water with oil. Should I switch to an electric water heater?

Answer: Depending on how efficient your oil-fired water heating system is, it may be less expensive to use an electric water heater. Many people have an oil-fired boiler that provides space and water heating. For older, less efficient systems it will cost more to use oil.

With electricity prices as of July 2008, it is also less expensive to use an electric water heater than a propane-fired one. If you only use propane to heat your water and not for space heating as well, electric water heaters can be a lot less expensive than propane-fired ones.

To estimate your kilowatt-hour use for heating water with an electric water heater, go to our online energy calculator and page down to the water heater section.

(Note: the efficiency measured when a boiler is serviced is the combustion efficiency. This is higher than the efficiency when it operates in the non-heating season.)

So, maybe you shouldn't be using the 80+% efficiency numbers for comparison of water heating only. I do realize that they are going to try to present facts in their favor, but there were times where thay said there wouldn't be savings for the electric options.

The link to their calculator is:
http://www2.cmpco.com/EnergyCalculator/default.jsp

Here is a link that might be useful: CMP heating FAQs

To the original question, I would plumb the electric water heater in after the boiler and set the boiler to operate only when household heat is needed. When the boiler is operating it will supply the electric water heater with hot water hence, the electric will not come on, any other time the electric will ensure hot water.

I would look into a Marathon lifetime warranty conventional electric water heater (they have a plastic tank) and extra insulation. I would also look into a heat pump water heating unit and get 2-3 units of hot water per unit of electricity!!

I have a 40 yr old boiler original to my house. Forced hot water by oil. It is a tankless hot water system. The boiler runs at 86% efficiency. I don't know if that is the same as a 1 or 2 year old system running at the same 86% efficiency. Is it cheaper to run an indirect Amtrol Boilermate type system or an electric hot water heater (tank)As it stands right now, every time the hot water is turned on, the boiler turns on. Oil is $3.59 to $3.89 per gallon. It's killin me. Anyone out there please advise.

Thanks

Same here, my mom has an oil furnace that also heats her water. I'm considering getting a regular hot water heater and let the oil furnace supply the heat not the hot water.

in nfld and lab now heating oil is around 9.00 dollars gallon and electricty is around 15 cents kilowat hour so replacing my hot water boiler with a electric hot water boiler for heating purposes and installing a separate electric hot water tank for domectic hot water .....not sure what would be cheaper

Is natural gas an option at your location?

What’s the capacity of your electrical entrance 100amp or 200amp?

What temperature hot water do your radiators want to see?

You should start a new thread. This one’s 14-yrs old!

SR