Electric boiler for cast iron radiators?

BoilerinBrunswick

Hey guys,

I currently have cast iron radiators with a heating oil boiler (circa 1985), no natural gas lines in my area. I'm thinking of going solar and have been researching electric boilers to replace my heating oil boiler. I can't seem to find much user data for electric boilers, anyone out there have an electric boiler and feel like sharing some usage data?

Most of the plumbers I talk to seem to think my electricity bills will be astronomical. Most solar people I talk to say they won't be too high, but none of them have an electric boiler. Based on my oil usage from last winter, I've estimated how many kWh of electricity I'd use (base on 70% efficiency for my current boiler which I think might be generous), it's not too bad, about what I paid for oil, before factoring in the solar. I only have one winter of data, and it was a fairly average winter. I also heat partially with a wood stove, and it wouldn't be too difficult to put radiant floor heating on the first floor, which I understand is more efficient than radiators and needs a lower water temp.

Another potential option is ductless mini splits, but I really love my radiators.

Any suggestions? My house is old but seems surprisingly tight, newer, high end windows, 1680 square feet, when the temp outside changes the house holds its temp for days before I have to turn on the heat. I planned to add insulation in the attic and basement as well.

leonz

If you have not had a heat loss study done I would see about having it done to save even more fuel.

Your boiler is 32 plus years old now. How much work has been done to maintain it? has the burner blower been cleaned?
Have you had the burners blower checked for combustion rates using manometer probe in the stack pipe?

Have the boiler tubes been brushed out and the dust and ash vacuumed out?

Has the barometric damper been removed, scrubbed and cleaned in hot water with dawn dish soap? Is the damper door weight in the correct position?

Have the radiators ever been flushed with a cleaner of some kind or just hot water?

Have you thought about using a smaller oil nozzle The burner will run longer but the consumption of oil per hour will decrease.

my thoughts anyway.

jumper

Presume you have hot water & not steam? You may get a break on electricity rate with time of use meter. Then you can think about thermal storage. Definitely a more efficient method to store solar electric energy than batteries. Plus air to water heat pumps are becoming more common.

What you say about electric boilers is the real problem. Nobody seems interested in selling a reasonably priced unpressurised storage electric boiler. You can make one yourself but that might not be legal. I'd install separate elements for metered and solar electricity. You'd have to figure out a strategy for using metered depending on weather forecast.

Jamie Hall

Depends some -- like a lot -- on where you live, since electric rates by about a factor of 5 between high cost areas and low cost areas. In any event, you have to remember that a BTU is a BTU, regardless of whether it comes in a tank or on a wire. A gallon of oil is around 140,000 BTU. A kilowatt hour is around 3,000 BTU. So you just need to do the math to figure out which is cheaper (multiply your electric rate by 47 and compare that number with a gallon of oil. Take into account efficiency, if you have real numbers on that (don't believe all the numbers on the appliance stickers!).

hot_rod

Is LP and option? It may be cheaper that electricity. I'd guess your design load under 30,000. A load calc would help drill down the operating cost difference. Plenty of online energy calculators.

Henry

Is your square footage for one floor or two. Your winter temperatures are similar to here in Montreal. If you have one floor, your load is 45,360 BTU. I use Thermolec boilers as they are made of S/S and are install and forget. You will need a B-15 which is 15Kw. Here due to our cheap electricity, savings from going oil to electric is between 40 to 50%! You can easily calculate your electrical cost by rule of thumb used by our utilities: 1000 hours of operation which in NB would probably be around 900.
thermolec.com/_documentationcache/cd-264-English%20Boiler%20flyer%20booklet.pdf

Leon82

Only way I would do it is if I owned the panels.
If you go with the free panels with a ppa the kw price raises every year.