Domestic Hot water question

ok, my source of heating my domestic hot water is a oil fired hot water radiation furnace system.
my problem is it takes way too long from the time I turn on my hot water taps to the point where i actually get hot water. The furnace has to turn on, water has to flow though the coil in the furnace and then flow upward to my taps. What I want to do is put in a non-heated storage tank (about 40 gallon) right after it comes out of the furnace. So when I turn on the hot water taps, it immediately comes from the storage tank, as it gets filled by the hot water coming from the furnace.
The tank would obviously be insulated very well to keep in the heat. Temp of water going into the tank would be about 180-190 degrees.
Does anyone see any problems with this setup? Have any suggestions or comments? I'm just throwing this idea out there.
My storage tank is an old oil fired hot water tank.
Thanks, Steve Cornick
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You may have several existing problems. With a domestic coil, the boiler should be maintaining hot water all the time, and should only need to fire when it's temp drops below the set minimum temperature. Your taps may be to far from the boiler and need a recirculating loop and pump installed to maintain hot water in the lines near the taps. If you want to use a storage tank, the most efficient thing to do, is get an indirect water heater, an insulated tank with a big coil in it, controlled by an aquastat and circulating pump off the boiler

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You have one of the most inefficient systems available. Makes a lot of hot water, but not very economical. That coil is not well insulated and the boiler kicks on too often just to keep some water hot. Last year I had a new boiler and indirect fired water heater installed. My oil savings so far are 32% for the same number of degree days.
This is what I have. http://www.energykinetics.com/productGallery.shtml#tanks The first hour water draw is over 200 gallons.
With the new boiler and water heater, I expect to save about 250 gallons of oil a year. Depending on the price of oil, payback will be from 6 to 12 years. TI was ready for a new boiler so I bought the most efficient I could find.
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Steve wrote:

Wouldn't your scheme mean you'd have to drain an extra 40 gallons from the system before your morning shower? That is, can you provide enough insulation to maintain an acceptable temperature for 12 or more hours?
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That's a good questoin. I guess I'd have to try it and find out what temperature I can maintain and for how long.
Steve
"HeyBub" wrote in message

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Your idea is a good one but may not be needed. Your domestic hot water thermostst may be bad. When I had an oil fired furnace/water heater the domestic water was hot all the time.
If you want to go with a storage tank they make them that behave as an additional heating zone on your furnace. http://www.ebuild.com/articles/521433.hwx
If the problem is that your faucets are too far away you may want to consider a hot water recirculation loop. This would require more plumbing work and depending on your house tearing into walls. http://www.redytemp.com/hot-water-recirculator-how-it-works.htm
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Lots of good advice above. To which I'd add, that if you were to implement a storage tank, I'd probably just get an electric water heater as the storage tank. That way it's guaranteed to have water at or above X temp. Since you'd be pre-heating the water, the electric usage would be very small. In the off heating season months, it may also be cheaper to just use the electric heater. Electric costs more, but it's 100% efficient, vs a lot less for a boiler that's just being used for hot water.
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snipped-for-privacy@optonline.net wrote:

walls.http://www.redytemp.com/hot-water-recirculator-how-it-works.htm- Hide quoted text -

If you add an electric water heater be sure to set its temperature below the furnace water temperature. This way the electric only draws current when the furnace cannot keep up with the load.
EJ in NJ
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I see the real purpose of the electric water heater being to kick in to MAINTAIN the tank temp, ie make up for the slow cooling of the water, not to increase the ability to handle a load. If you just had a 40 gallon storage tank with no heating capability, you'd have a problem when it does cool down. For example, you go on vacation for a week. Then you'd have to go through 40 gallons of cool water sitting in the tank.
I do agree the temp of the water heater should be lower than the temp of the boiler hot water. Still, the bigger problem is that something is clearly wrong here. Boiler delivered hot water should not take a long time.
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At my mothers house, she has an Amitrol BoilerMate water tank. It has a connection to an oil fired boiler. When the water in the tank drops below a certain temperature it signals the boiler to come on. The boiler heats water and it is sent through a coil in the BoilerMate to heat the water in the tank.
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Someone posted this link recently and I thought it looked like an interesting approach:
http://www.chilipepperapp.com /
If you click around the website it explains the whole system in detail, how it works, etc.
Steve wrote:

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Steve wrote:

the time the boiler coil puts out it heats the point of use heater back up. You can put a 6 gallon unit right under the sink. No tank is going to stay hot without a heat source.
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I can not see how what you have now, even if it was working correctly is an efficient way to heat water in summer when the boiler is off. A storage tank will just cool and waste energy if you pay to heat it to 180-190. Depending on your KWH cost a seperate Propane water heater tank or electric is an idea. In winter what you have should heat fairly efficiently. Look at a System 2000 for oil its better all around.
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An oil-fired furnace that provides domestic hot water is in effect an instant water heater. They only keep a few gallons of water hot when idle and can easily keep up with showering and washing clothes. Another benefit is the furnace stays running year round and doesn't collect moisture and rust out.

That is exactly what an electric/propane/gas water heater does/is so it would be just as efficient and ignoring the sillyness of last year oil is cheaper than gas and way cheaper than electric.
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An oil-fired furnace that provides domestic hot water is in effect an instant water heater. They only keep a few gallons of water hot when idle and can easily keep up with showering and washing clothes. Another benefit is the furnace stays running year round and doesn't collect moisture and rust out.
*******************************************************
Next to electric though, it is the most expensive way to heat water in the off heating season. Many times at night I'd lay in bed and hear the boiler turn on to keep the water hot as it is a poorly insulated setup. The utility are is also considerably warmer than it has to be from the heat lost to atmosphere. With my new system, that part of the house has dropped about 10 degrees. There are many better ways of heating water. Yes, it does keep up as you say, but at a cost.

That is exactly what an electric/propane/gas water heater does/is so it would be just as efficient and ignoring the sillyness of last year oil is cheaper than gas and way cheaper than electric.
****************************************************** Keeping 40 or 50 gallons hot in a well insualted tank is economical though. My tanks loses about 6 degrees in 24 hours. It can go a day, maybe two, without the boiler running at all. New tanks generally have two inches of foam insulation on all sides. It should not be heated to 180 degrees anyway. 130 is sufficient.
As for oil cheaper than gas, perhaps where you live. Where I live it is about 50% higher.
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