Boiler backup - electric?

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maple1

Minister of Fire
Sep 15, 2011
11,082
Nova Scotia
Who all is using electric for backup? Like either an electric boiler, or a tank with elements in it. I've been almost set on getting a new compact oil boiler for backup, but with the ever changing price of oil (not that electricity is cheap & stable itself though), and how little I HOPE to be having to use back up, and the thoughts of getting totally rid of oil furnace/tank etc. - well, I'm having second thoughts on it. There seem to be a few fairly new second hand electric boilers around - Thermolec, Slant Fin - are there good & bad? Those who use it, what are your setups and the goods & bads?
 
How do the fuel prices compare, and how often will you be running on back up? The brands you mentioned are all good ones. I like the Thermolec, nice size, well built and I think all models now have a simple outdoor reset function.

Electric boilers are common in areas with low power rates and low off peak rates. Most have a very small fluid capacity and they warm up quickly for those shoulder season start and stops. Pipe the electric boiler directly to the loads, bypassing the storage, unless you have off peak and thermal storage pencils out.

Electric boilers are small and easy to install, service, and repair. But you will need to determine if you have enough capacity in your electrical panel to power it.

hr
 
I guess that's why I don't know much about them - they're not used much here compared to other sources. Or at least haven't been with ready wood access & traditionally high electric rates. I think the ones I'm seeing for sale are due to people converting from electric to geothermal. Right now (CDN after taxes) electric here is around $0.15/kwh, and oil is around $1.10/litre. Electric rates are on a gradual trend up (like everything else), while oil as everyone knows is crazy volatile (a year and a half ago it was $0.85/litre). I'm thinking long term that electric should be more stable although increasing - especially with more wind power coming on line, more hydro getting here, & tidal around the corner. I've been using about 180 gallons/yr of oil for DHW & backup, mostly for DWH - thinking I should be able to cut that in half easily with new furnaces & storage, and maybe even flirt with zero if I can get around to lighting a fire during the summer every few days. We are away from home during the winter for no more than a long weekend, maybe 4-5 days over Christmas too, depending on the year.

We have a 200a entrance, so should be good there - I should have run this by the electrician while he was here last month giving me some generator input.
 
I installed four elements and t'stats in my upper storage tank (two horizontally stacked 800gal) along the center-line of the tank, just in case I want to take a vacation in the winter. So far I haven't turned them on. It was alot cheaper than an electric boiler and didnt require any extra space or piping, materials were about 120$ (couplings, elements, and t'stats). Dont know the cost of the wire and breakers as it was installed with the rest of my house's electrical.

A coworker installed a radiant floor system using one electric element (for one large room) for heat which was threaded into a piece of 2" pipe. He used a modulating controller, but a simple t'stat likely would have worked almost as well. As long as you configure things safely (relief valves piped to floor, exp tank ect.) and wire things to code I don't see a problem with using elements how ever you please.
 
clever idea adding the elements into the storage.

You can buy assembled element/ thermostat immersion setup from Chromolox and others, they will be UL listed or cUL.

Be sure you have a control with over temperature protection. The upper thermostat control used on most electric water heaters has temperature control and a red, re-setable, over temperature reset button.

hr
 
Garth B said:
I installed four elements and t'stats in my upper storage tank (two horizontally stacked 800gal) along the center-line of the tank, just in case I want to take a vacation in the winter. So far I haven't turned them on. It was alot cheaper than an electric boiler and didnt require any extra space or piping, materials were about 120$ (couplings, elements, and t'stats). Dont know the cost of the wire and breakers as it was installed with the rest of my house's electrical.

A coworker installed a radiant floor system using one electric element (for one large room) for heat which was threaded into a piece of 2" pipe. He used a modulating controller, but a simple t'stat likely would have worked almost as well. As long as you configure things safely (relief valves piped to floor, exp tank ect.) and wire things to code I don't see a problem with using elements how ever you please.

Now you've really got me thinking. Does each element have its own thermostat, or one thermostat for each one? Do you know the ratings of your elements? What size did the holes have to be? Where did you use the couplings at? So many questions...
 
There is a house in an adjacent town with a 2500 gallon storage tank that is hooked up to a Madawaska wood boiler (Dick Hills design). In order to get a mortgage on the house the owner installed an electric imersion heater in the tank. NH has an off peak electric storage rate. At some point the wood boiler belched flames at his wife and she wouldnt use it. Last thing I knew the wood boiler is not used and they heat cheaper with electricity. The house is a double envelope house so it doesnt have much heat load.
 
Just FYI. Garn has all of their models available with and electric backup package that can go as high as 200 Amp. There are a few in service near places with off peak hydro rates that have never had a wood fire in them from what I have been told.
They are also in the process of getting final approvals on electrically heated storage tanks that will sit outside and pipe into a house much like a wood burner. In places with good off peak rates it makes a lot of sense ans utilities need somewhere to go with the output from variable sources like wind and tide. It allows them to "park" their power output.
 
I was going to say electric tankless (I have propane tankless) but the in storage element sounds like a great idea. Electric is cheaper than propane for me and I could keep my storage at say 120/130 at the top of the tank. I have the AC service to support it (400A panel - plan for expansion!).
 
There is not much difference between electricity and propane for me, but a 150kw load and the supply needed knocked it out. I had Propane tanks and need it for cooking.
 
Well, this mornings news here is that our power rates will be going up somewhere around 10%.

Does anyone elses electric utility (ours is private) have an 8% guaranteed rate of return for investors factored into the rate setting process?

Oops, I'm getting political and my BP is rising.

I think I'm leaning back to oil backup again - uggghh.
 
They made the contributions to their favourite Politicians, are they not entitled to their return?
 
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