Any ideas on electric backup for hot water oil heat?

[Seasoned Oak]

My problem is i have oil hot water heat in several investment properties that is not 100% reliable. Either running out of oil or furnace malfunction will leave the property without heat.
IF its not discovered in time a lot of busted water pipes may result. The ELectric furnaces i have seen advertised are over a $1000. A lot of dough for a backup heat source that may never be used.
A $200, 30 gallon hot water heater could be converted to do this backup but the problem is if its left cold and filled with water for an extended period it will rust out very quickly.
I do not need to heat the house with this backup, just provide enough hot water to keep the heat pipes from freezing and a small amount of heat to keep the home temp above 32 for the rest of the plumbing

 

[DBoon]

If you are worried about a cold hot water tank rusting out, check out the Marathon hot water heaters. They are a polybutylene tank with no metal or anode. They should last virtually forever unless you have very hard water.

 

[pybyr]

What about some form of tankless water heater?

With a tank-type water heater, I'd expect that it might take a considerable period of time for it to supply enough BTUs if it is having to climb from stone cold and deliver heat to a load at the same time.

 

[Seasoned Oak]

Im now Re-thinking my idea of using a standard hot water heater as a freeze proof backup heat ,probably the best approach is a very small electric hydronic furnace, as it actually designed to be an inline instantaneous water heater,or even a small domestic in line water heater as the load will be a fraction of that needed to heat the space to room temp. Id be happy with 40 degrees room temp,just enoughto keep things from freezing. Only problem with these two ideas is the big upfront cost.

 

[Gooserider]

No idea if it would meet code, or have other issues from a functional standpoint, but I've heard of people doing a home brew flow-through water heater by taking a length of fairly large diameter (3-4"?) schedule 40 steel pipe, and mounting a water heater element in one end cap, and adding appropriate end fittings to hook up to the system - sort of like doing a sidearm HX only with a heater element in the middle instead of a hot water supply...

No idea how well it worked in practice, but seems like it might be a way to do an electric backup heat source w/o needing a lot of expensive hardware... It would probably want to have some pretty solid control hardware though, as you'd want to be certain you had flow any time the power was on, among other issues....

Gooserider

 

[Seasoned Oak]

No idea if it would meet code, or have other issues from a functional standpoint, but I've heard of people doing a home brew flow-through water heater by taking a length of fairly large diameter (3-4"?) schedule 40 steel pipe, and mounting a water heater element in one end cap, and adding appropriate end fittings to hook up to the system - sort of like doing a sidearm HX only with a heater element in the middle instead of a hot water supply...

No idea how well it worked in practice, but seems like it might be a way to do an electric backup heat source w/o needing a lot of expensive hardware... It would probably want to have some pretty solid control hardware though, as you'd want to be certain you had flow any time the power was on, among other issues....

Gooserider

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I was thinking of something similar. Water heater elements are fairly cheap, and im thinking something i could supply with a piece of #8 electric wire on a 40 or 50Amp breaker.
Another alternative is to just buy a small electric boiler, perhaps from Ebay. THe ones iv seen in use are pretty small in size, but they were heating the whole house on a continuous basis to 70 Deg
Regards

 

[Vtgent49]

There are lots of empty second homes around here (ski country VT) and they have similar issues. Almost all use glycol in their boiler as one way to prevent damage during a freeze-up.
I supply a lot of electronic monitors that watch the temp and watch for water spillage/leak/sump pump failure. These are one time cost, not a monthly fee to monitor the system, and can be owner installed. The Monitor will call up to 3 phone numbers in the event of an alarm. They watch temps, water leak and power outages of an hour or more. More info on my website on the unit I think is best, but there are many similar units available. You have to have an active landline, and if you have multiple units installed, then you have to note the caller ID when a call comes in.